Upon TPA treatment , the activity of ERK1 and ERK2 rapidly increased , with maximal induction between 1 and 3 h , while ERK2 protein levels remained constant .

Upon TPA treatment , the activity of <protein>ERK1</protein> and <protein>ERK2</protein> rapidly increased , with maximal induction between 1 and 3 h , while <protein>ERK2</protein> protein levels remained constant .


The activity of JNK1 was also significantly induced , with JNK1 protein levels increasing moderately during exposure to TPA .

The activity of <protein>JNK1</protein> was also significantly induced , with <protein>JNK1</protein> protein levels increasing moderately during exposure to TPA .


Treatment of cells with PD98059 , a specific inhibitor of mitogen-activated protein kinase kinase ( MEK ) , inhibited TPA-induced ERK2 activity .

Treatment of cells with PD98059 , a specific inhibitor of <protein>mitogen-activated protein kinase kinase</protein> ( <protein>MEK</protein> ) , inhibited TPA-induced <protein>ERK2</protein> activity .


Furthermore , PD98059 completely blocked the TPA-induced differentiation of ML-1 cells , as assessed by a number of features associated with mononuclear differentiation including changes in morphology , nonspecific esterase activity , phagocytic ability , NADPH oxidase activity , mitochondrial respiration , and c-jun mRNA inducibility .

Furthermore , PD98059 completely blocked the TPA-induced differentiation of <cell_line>ML-1 cells</cell_line> , as assessed by a number of features associated with mononuclear differentiation including changes in morphology , nonspecific <protein>esterase</protein> activity , phagocytic ability , <protein>NADPH oxidase</protein> activity , mitochondrial respiration , and <rna>c-jun mRNA</rna> inducibility .


We conclude that activation of the MEK /ERK signaling pathway is necessary for TPA-induced mononuclear cell differentiation .

We conclude that activation of the <protein>MEK</protein> /ERK signaling pathway is necessary for TPA-induced mononuclear cell differentiation .


Glucocorticoid receptors in anorexia nervosa and Cushing 's disease .

<protein>Glucocorticoid receptors</protein> in anorexia nervosa and Cushing 's disease .


BACKGROUND : Patients with anorexia nervosa do not display cushingoid features in spite of elevated cortisol plasma levels .


Whether a cortisol resistance or a reduced availability of the metabolic substrates necessary to develop the effect of glucocorticoids is responsible for this has not been established .


METHODS : Twenty-two patients with severe restrictive anorexia nervosa , 10 patients with active Cushing 's disease , and 24 healthy volunteers without psychiatric disorders or mood alterations were investigated .


Glucocorticoid receptor characteristics were examined on mononuclear leukocytes by measuring [ 3H ] dexamethasone binding and the effect of dexamethasone on [ 3H ] thymidine incorporation , which represents an index of DNA synthesis .

Glucocorticoid receptor characteristics were examined on <cell_type>mononuclear leukocytes</cell_type> by measuring [ 3H ] dexamethasone binding and the effect of dexamethasone on [ 3H ] thymidine incorporation , which represents an index of DNA synthesis .


RESULTS : The number of glucocorticoid receptors on mononuclear leukocytes ( MNL ) was comparable in patients with anorexia nervosa , patients with active Cushing 's disease , and normal subjects ( binding capacity 3.3 +/- 0.23 vs. 3.7 +/- 0.30 and 3.5 +/- 0.20 fmol/10 ( 6 ) cells ) .

RESULTS : The number of <protein>glucocorticoid receptors</protein> on <cell_type>mononuclear leukocytes</cell_type> ( <cell_type>MNL</cell_type> ) was comparable in patients with anorexia nervosa , patients with active Cushing 's disease , and normal subjects ( binding capacity 3.3 +/- 0.23 vs. 3.7 +/- 0.30 and 3.5 +/- 0.20 fmol/10 ( 6 ) cells ) .


Conversely , glucocorticoid receptor affinity was significantly decreased in anorexia nervosa as well as in Cushing 's patients compared to control subjects ( dissociation constant 4.0 +/- 0.31 and 4.1 +/- 0.34 vs. 2.9 +/- 0.29 nmol/L , p < .001 ) and inversely correlated with the levels of urinary free cortisol in both groups of patients .

Conversely , <protein>glucocorticoid receptor</protein> affinity was significantly decreased in anorexia nervosa as well as in Cushing 's patients compared to control subjects ( dissociation constant 4.0 +/- 0.31 and 4.1 +/- 0.34 vs. 2.9 +/- 0.29 nmol/L , p < .001 ) and inversely correlated with the levels of urinary free cortisol in both groups of patients .


Basal [ 3H ] thymidine incorporation in MNL was significantly reduced in anorexia nervosa as well as in Cushing 's patients compared to control subjects ( p < .001 ) and was diminished by dexamethasone to an extent similar to control subjects in patients with anorexia nervosa , but significantly ( p < .001 ) less in those with Cushing 's disease .

Basal [ 3H ] thymidine incorporation in <cell_type>MNL</cell_type> was significantly reduced in anorexia nervosa as well as in Cushing 's patients compared to control subjects ( p < .001 ) and was diminished by dexamethasone to an extent similar to control subjects in patients with anorexia nervosa , but significantly ( p < .001 ) less in those with Cushing 's disease .


In patients with anorexia nervosa , the incorporation of [ 3H ] thymidine into the MNL was inversely correlated with urinary free cortisol levels .

In patients with anorexia nervosa , the incorporation of [ 3H ] thymidine into the <cell_type>MNL</cell_type> was inversely correlated with urinary free cortisol levels .


CONCLUSIONS : These data indicate that the lack of cushingoid features in patients with anorexia nervosa is not ascribable to a reduced sensitivity to glucocorticoids but is more likely due to the paucity of metabolic substrates .


Different sequence requirements for expression in erythroid and megakaryocytic cells within a regulatory element upstream of the GATA-1 gene .

Different sequence requirements for expression in <cell_type>erythroid and megakaryocytic cells</cell_type> within a <dna>regulatory element</dna> upstream of the <dna>GATA-1 gene</dna> .


The lineage-restricted transcription factor GATA-1 is required for differentiation of erythroid and megakaryocytic cells .

The <protein>lineage-restricted transcription factor</protein> <protein>GATA-1</protein> is required for differentiation of <cell_type>erythroid and megakaryocytic cells</cell_type> .


We have localized a 317 base pair cis-acting regulatory element , HS I , associated with a hematopoietic-specific DNase I hypersensitive site , which lies approx .

We have localized a 317 base pair <dna>cis-acting regulatory element</dna> , <dna>HS I</dna> , associated with a <dna>hematopoietic-specific DNase I hypersensitive site</dna> , which lies approx .


3.7 kilobases upstream of the murine hematopoietic-specific GATA-1 IE promoter .

3.7 kilobases upstream of the <dna>murine hematopoietic-specific GATA-1 IE promoter</dna> .


HS I directs high-level expression of reporter GATA-1/lacZ genes to primitive and definitive erythroid cells and megakaryocytes in transgenic mice .

<dna>HS I</dna> directs high-level expression of reporter <dna>GATA-1/lacZ genes</dna> to <cell_type>primitive and definitive erythroid cells</cell_type> and <cell_type>megakaryocytes</cell_type> in transgenic mice .


Comparative sequence analysis of HS I between human and mouse shows approx .

Comparative sequence analysis of <dna>HS I</dna> between human and mouse shows approx .


63 % nucleotide identity with a more conserved core of 169 base pairs ( 86 % identity ) .

63 % nucleotide identity with a more conserved core of <dna>169 base pairs</dna> ( 86 % identity ) .


This core contains a GATA site separated by 10 base pairs from an E-box motif .

This core contains a <dna>GATA site</dna> separated by 10 base pairs from an <dna>E-box motif</dna> .


The composite motif binds a multi-protein hematopoietic-specific transcription factor complex which includes GATA-1 , SCL/tal-1 , E2A , Lmo2 and Ldb-1 .

The <dna>composite motif</dna> binds a <protein>multi-protein hematopoietic-specific transcription factor complex</protein> which includes <protein>GATA-1</protein> , <protein>SCL/tal-1 ,</protein> <protein>E2A</protein> , <protein>Lmo2</protein> and <protein>Ldb-1</protein> .


Point mutations of the GATA site abolishes HS I function , whereas mutation of the E-box motif still allows reporter gene expression in both lineages .

Point mutations of the <dna>GATA site</dna> abolishes <dna>HS I</dna> function , whereas mutation of the <dna>E-box motif</dna> still allows reporter gene expression in both lineages .


Strict dependence of HS I activity on a GATA site implies that assembly of a protein complex containing a GATA-factor , presumably GATA-1 or GATA-2 , is critical to activating or maintaining its function .

Strict dependence of <dna>HS I</dna> activity on a <dna>GATA site</dna> implies that assembly of a protein complex containing a <protein>GATA-factor</protein> , presumably <protein>GATA-1</protein> or <protein>GATA-2</protein> , is critical to activating or maintaining its function .


Further dissection of the 317 base pair region demonstrates that , whereas all 317 base pairs are required for expression in megakaryocytes , only the 5 ' 62 base pairs are needed for erythroid-specific reporter expression .

Further dissection of the <dna>317 base pair region</dna> demonstrates that , whereas all <dna>317 base pairs</dna> are required for expression in <cell_type>megakaryocytes</cell_type> , only the <dna>5 ' 62 base pairs</dna> are needed for erythroid-specific reporter expression .


These findings demonstrate differential lineage requirements for expression within the HS I element .

These findings demonstrate differential lineage requirements for expression within the <dna>HS I element</dna> .


Non-steroidal anti-inflammatory drugs inhibit the expression of cytokines and induce HSP70 in human monocytes .

Non-steroidal anti-inflammatory drugs inhibit the expression of <protein>cytokines</protein> and induce <protein>HSP70</protein> in <cell_type>human monocytes</cell_type> .


Recent studies have shown that the non-steroidal anti-inflammatory drugs ( NSAIDs ) activate heat shock transcription factor ( HSF1 ) from a latent cytoplasmic form to a nuclear , DNA binding state .

Recent studies have shown that the non-steroidal anti-inflammatory drugs ( NSAIDs ) activate <protein>heat shock transcription factor</protein> ( <protein>HSF1</protein> ) from a <protein>latent cytoplasmic form</protein> to a <protein>nuclear , DNA binding state</protein> .


As HSF1 can function as both an activator of heat shock genes and a repressor of non-heat shock genes such as IL1B and c- fos , we have examined the potential role of HSF1 in the effects of NSAIDs on gene expression in a human monocytic cell line THP-1 .

As <protein>HSF1</protein> can function as both an activator of <dna>heat shock genes</dna> and a repressor of <dna>non-heat shock genes</dna> such as IL1B and c- fos , we have examined the potential role of <protein>HSF1</protein> in the effects of NSAIDs on gene expression in a human <cell_line>monocytic cell line THP-1</cell_line> .


We found that two members of the NSAIDs , sodium salicylate and sulindac repress the IL1B promoter to similar degree to heat shock or HSF1 overexpression .

We found that two members of the NSAIDs , sodium salicylate and sulindac repress the <dna>IL1B promoter</dna> to similar degree to heat shock or <protein>HSF1</protein> overexpression .


In addition , sodium salicylate and additional NSAIDs used at concentrations that activate HSF1 also inhibited the expression of other monocytic genes ( TNF-alpha , IL-1beta , IL-6 , IL-8 , IL-10 , ICAM-1 ) activated by exposure to a pro-inflammatory stimulus ( lipopolysaccharide , LPS ) .

In addition , sodium salicylate and additional NSAIDs used at concentrations that activate <protein>HSF1</protein> also inhibited the expression of other <dna>monocytic genes</dna> ( <dna>TNF-alpha</dna> , <dna>IL-1beta</dna> , <dna>IL-6</dna> , <dna>IL-8</dna> , <dna>IL-10</dna> , <dna>ICAM-1</dna> ) activated by exposure to a pro-inflammatory stimulus ( lipopolysaccharide , LPS ) .


At least in the case of the IL1B promoter , repression did not seem to involve another factor whose activity is affected by the NSAIDs , NFkappaB as the IL1B promoter fragment used in our studies is not NFkappaB responsive and binds specifically to HSF1 .

At least in the case of the <dna>IL1B promoter</dna> , repression did not seem to involve another factor whose activity is affected by the NSAIDs , <protein>NFkappaB</protein> as the <dna>IL1B promoter fragment</dna> used in our studies is not <protein>NFkappaB</protein> responsive and binds specifically to <protein>HSF1</protein> .


Exposure to NSAIDs had a complex effect on HSP gene expression and while sulindac activated the stress responsive HSP70B promoter , sodium salicylate did not .

Exposure to NSAIDs had a complex effect on HSP gene expression and while sulindac activated the stress responsive <dna>HSP70B promoter</dna> , sodium salicylate did not .


In addition , only a subset of the NSAIDs induced HSP70 mRNA species .

In addition , only a subset of the NSAIDs induced <rna>HSP70 mRNA species</rna> .


These findings reflect the properties of HSF1 which can be activated to at least two DNA binding forms only one of which activates heat shock promoters and suggest that individual NSAID family members may differentially induce one or other of these forms .

These findings reflect the properties of <protein>HSF1</protein> which can be activated to at least two <protein>DNA binding forms</protein> only one of which activates <dna>heat shock promoters</dna> and suggest that individual NSAID family members may differentially induce one or other of these forms .


Overall therefore , exposure to NSAIDs leads to a profound switch in gene expression in monocytic cells , with suppression of genes involved in macrophage activation and induction of stress genes and HSF1 appears to play a regulatory role in these effects .

Overall therefore , exposure to NSAIDs leads to a profound switch in gene expression in <cell_type>monocytic cells</cell_type> , with suppression of genes involved in macrophage activation and induction of <dna>stress genes</dna> and <protein>HSF1</protein> appears to play a regulatory role in these effects .


Copyright 1999 Academic Press .


Immortalization of CD4 ( + ) and CD8 ( + ) T lymphocytes by human T-cell leukemia virus type 1 Tax mutants expressed in a functional molecular clone .

Immortalization of <cell_type>CD4 ( + ) and CD8 ( + ) T lymphocytes</cell_type> by human T-cell leukemia virus type 1 <protein>Tax mutants</protein> expressed in a <cell_line>functional molecular clone</cell_line> .


The human T-cell leukemia virus type 1 ( HTLV-1 ) transcriptional trans-activator Tax has been demonstrated to have transforming activity in multiple cell culture and transgenic-mouse models .

The <protein>human T-cell leukemia virus type 1 ( HTLV-1 ) transcriptional trans-activator</protein> <protein>Tax</protein> has been demonstrated to have transforming activity in <cell_line>multiple cell culture</cell_line> and transgenic-mouse models .


In addition to activating transcription from the viral long terminal repeat ( LTR ) through the cyclic AMP response element binding protein/activating transcription factor ( CREB/ATF ) family of transcription factors , Tax activates the expression of multiple cellular promoters through the NF-kappaB pathway of transcriptional activation .

In addition to activating transcription from the <dna>viral long terminal repeat</dna> ( <dna>LTR</dna> ) through the <protein>cyclic AMP response element binding protein/activating transcription factor ( CREB/ATF ) family</protein> of <protein>transcription factors</protein> , <protein>Tax</protein> activates the expression of <dna>multiple cellular promoters</dna> through the <protein>NF-kappaB</protein> pathway of transcriptional activation .


The Tax mutants M22 and M47 have previously been demonstrated to selectively abrogate the ability of Tax to activate transcription through the NF-kappaB or CREB/ATF pathway , respectively .

The <protein>Tax mutants</protein> <protein>M22</protein> and <protein>M47</protein> have previously been demonstrated to selectively abrogate the ability of <protein>Tax</protein> to activate transcription through the NF-kappaB or CREB/ATF pathway , respectively .


These mutations were introduced in the tax gene of the ACH functional molecular clone of HTLV-1 , and virus produced from the mutant ACH clones was examined for the ability to replicate and immortalize primary human lymphocytes .

These mutations were introduced in the <dna>tax gene</dna> of the <dna>ACH functional molecular clone</dna> of HTLV-1 , and virus produced from the <dna>mutant ACH clones</dna> was examined for the ability to replicate and immortalize <cell_type>primary human lymphocytes</cell_type> .


While virus derived from the clone containing the M47 mutation retained the ability to immortalize T lymphocytes , the M22 mutant lost the ability to immortalize infected cells .

While virus derived from the clone containing the <protein>M47</protein> mutation retained the ability to immortalize <cell_type>T lymphocytes</cell_type> , the <protein>M22</protein> mutant lost the ability to immortalize <cell_type>infected cells</cell_type> .


These results indicate that activation of the CREB/ATF pathway by Tax is dispensable for the immortalization of T cells by HTLV-1 , whereas activation of the NF-kappaB pathway may be critical .

These results indicate that activation of the <protein>CREB/ATF</protein> pathway by <protein>Tax</protein> is dispensable for the immortalization of <cell_type>T cells</cell_type> by HTLV-1 , whereas activation of the <protein>NF-kappaB</protein> pathway may be critical .


Fibroblast growth factor-1 ( FGF-1 ) enhances IL-2 production and nuclear translocation of NF-kappaB in FGF receptor-bearing Jurkat T cells .

<protein>Fibroblast growth factor-1</protein> ( <protein>FGF-1</protein> ) enhances <protein>IL-2</protein> production and nuclear translocation of <protein>NF-kappaB</protein> in <cell_line>FGF receptor-bearing Jurkat T cells</cell_line> .


Fibroblast growth factors ( FGFs ) are heparin-binding proteins crucial to embryogenesis , angiogenesis , and wound healing .

<protein>Fibroblast growth factors</protein> ( <protein>FGFs</protein> ) are <protein>heparin-binding proteins</protein> crucial to embryogenesis , angiogenesis , and wound healing .


FGF-1 is abundantly expressed in the synovium in rheumatoid arthritis and in rejecting allografts , sites of chronic immune-mediated inflammation .

<protein>FGF-1</protein> is abundantly expressed in the synovium in rheumatoid arthritis and in rejecting allografts , sites of chronic immune-mediated inflammation .


The frequency of FGF-1 -responsive T cells is increased in the peripheral blood of these disorders , and a high percentage of infiltrating T cells in rheumatoid arthritis synovium express receptors for FGF-1 .

The frequency of <protein>FGF-1</protein> -responsive <cell_type>T cells</cell_type> is increased in the peripheral blood of these disorders , and a high percentage of <cell_type>infiltrating T cells</cell_type> in rheumatoid arthritis synovium express receptors for <protein>FGF-1</protein> .


To understand the action of FGF-1 in T cells , studies were initiated in Jurkat T cells that express the signaling isoform of FGF receptor-1 .

To understand the action of <protein>FGF-1</protein> in <cell_type>T cells</cell_type> , studies were initiated in <cell_line>Jurkat T cells</cell_line> that express the signaling isoform of <protein>FGF receptor-1</protein> .


These experiments show that FGF-1 stimulation of Jurkat T cells provides a second signal that augments TCR-mediated IL-2 production .

These experiments show that <protein>FGF-1</protein> stimulation of <cell_line>Jurkat T cells</cell_line> provides a second signal that augments TCR-mediated <protein>IL-2</protein> production .


Analogous to costimulation via CD28 , this activity is mediated through activation of Rel/kappaB , a family of transcription factors known to regulate IL-2 and other activation-inducible proteins .

Analogous to costimulation via <protein>CD28</protein> , this activity is mediated through activation of <protein>Rel/kappaB</protein> , a family of <protein>transcription factors</protein> known to regulate <protein>IL-2</protein> and other <protein>activation-inducible proteins</protein> .


FGF-1 alone induces modest nuclear translocation of kappaB-binding proteins , and this translocation is enhanced by the combination of anti-CD3 and FGF-1 .

<protein>FGF-1</protein> alone induces modest nuclear translocation of <protein>kappaB-binding proteins</protein> , and this translocation is enhanced by the combination of <protein>anti-CD3</protein> and <protein>FGF-1</protein> .


This NF-kappaB binding complex is composed of transcriptionally active p65 ( RelA ) /p50 heterodimers and results primarily from the targeted degradation of IkappaB-alpha , an inhibitor that sequesters Rel/kappaB in the cytoplasm .

This <protein>NF-kappaB binding complex</protein> is composed of <protein>transcriptionally active p65 ( RelA ) /p50 heterodimers</protein> and results primarily from the targeted degradation of <protein>IkappaB-alpha</protein> , an inhibitor that sequesters <protein>Rel/kappaB</protein> in the cytoplasm .


These data are the first to show a connection between FGF-1 signaling and NF-kappaB activation outside of embryonic development .

These data are the first to show a connection between <protein>FGF-1</protein> signaling and <protein>NF-kappaB</protein> activation outside of embryonic development .


The signaling events that link FGF receptor-1 engagement and NF-kappaB activation in Jurkat are probably distinct from the CD28 costimulation pathway , since FGF-1 -induced Rel/kappaB binding proteins do not contain significant levels of c-Rel and are not identical with the CD28 response complex .

The signaling events that link <protein>FGF receptor-1</protein> engagement and <protein>NF-kappaB</protein> activation in <cell_line>Jurkat</cell_line> are probably distinct from the <protein>CD28</protein> costimulation pathway , since <protein>FGF-1</protein> -induced <protein>Rel/kappaB binding proteins</protein> do not contain significant levels of <protein>c-Rel</protein> and are not identical with the <protein>CD28 response complex</protein> .


Escape of human cytomegalovirus from HLA-DR -restricted CD4 ( + ) T-cell response is mediated by repression of gamma interferon -induced class II transactivator expression .

Escape of human cytomegalovirus from <protein>HLA-DR</protein> -restricted CD4 ( + ) T-cell response is mediated by repression of <protein>gamma interferon</protein> -induced <protein>class II transactivator</protein> expression .


Human cytomegalovirus ( HCMV ) , a betaherpesvirus , is a pathogen which escapes immune recognition through various mechanisms .


In this paper , we show that HCMV down regulates gamma interferon ( IFN-gamma ) -induced HLA-DR expression in U373 MG astrocytoma cells due to a defect downstream of STAT1 phosphorylation and nuclear translocation .

In this paper , we show that HCMV down regulates gamma interferon ( <protein>IFN-gamma</protein> ) -induced <protein>HLA-DR</protein> expression in <cell_line>U373 MG astrocytoma cells</cell_line> due to a defect downstream of <protein>STAT1</protein> phosphorylation and nuclear translocation .


Repression of class II transactivator ( CIITA ) mRNA expression is detected within the first hours of IFN-gamma -HCMV coincubation and results in the absence of HLA-DR synthesis .

Repression of class II transactivator ( <dna>CIITA</dna> ) mRNA expression is detected within the first hours of <protein>IFN-gamma</protein> -HCMV coincubation and results in the absence of <protein>HLA-DR</protein> synthesis .


This defect leads to the absence of presentation of the major immediate-early protein IE1 to specific CD4 ( + ) T-cell clones when U373 MG cells , used as antigen-presenting cells , are treated with IFN-gamma plus HCMV .

This defect leads to the absence of presentation of the <protein>major immediate-early protein</protein> <protein>IE1</protein> to specific <cell_line>CD4 ( + ) T-cell clones</cell_line> when <cell_line>U373 MG cells</cell_line> , used as <cell_type>antigen-presenting cells</cell_type> , are treated with <protein>IFN-gamma</protein> plus HCMV .


However , presentation of endogenously synthesized IE1 can be restored when U373 MG cells are transfected with CIITA prior to infection with HCMV .

However , presentation of endogenously synthesized <protein>IE1</protein> can be restored when <cell_line>U373 MG cells</cell_line> are transfected with <dna>CIITA</dna> prior to infection with HCMV .


Altogether , the data indicate that the defect induced by HCMV resides in the activation of the IFN-gamma-responsive promoter of CIITA .

Altogether , the data indicate that the defect induced by HCMV resides in the activation of the <dna>IFN-gamma-responsive promoter</dna> of <dna>CIITA</dna> .


This is the first demonstration of a viral inhibition of CIITA expression .

This is the first demonstration of a viral inhibition of <dna>CIITA</dna> expression .


3-deazaadenosine , a S-adenosylhomocysteine hydrolase inhibitor , has dual effects on NF-kappaB regulation .

3-deazaadenosine , a <protein>S-adenosylhomocysteine hydrolase</protein> inhibitor , has dual effects on <protein>NF-kappaB</protein> regulation .


Inhibition of NF-kappaB transcriptional activity and promotion of IkappaBalpha degradation .

Inhibition of <protein>NF-kappaB</protein> transcriptional activity and promotion of <protein>IkappaBalpha</protein> degradation .


Previously we reported that 3-deazaadenosine ( DZA ) , a potent inhibitor and substrate for S-adenosylhomocysteine hydrolase inhibits bacterial lipopolysaccharide-induced transcription of tumor necrosis factor-alpha and interleukin-1beta in mouse macrophage RAW 264.7 cells .

Previously we reported that 3-deazaadenosine ( DZA ) , a potent inhibitor and substrate for <protein>S-adenosylhomocysteine hydrolase</protein> inhibits bacterial lipopolysaccharide-induced transcription of <protein>tumor necrosis factor-alpha</protein> and <protein>interleukin-1beta</protein> in <cell_line>mouse macrophage RAW 264.7 cells</cell_line> .


In this study , we demonstrate the effects of DZA on nuclear factor-kappaB ( NF-kappaB ) regulation .

In this study , we demonstrate the effects of DZA on <protein>nuclear factor-kappaB</protein> ( <protein>NF-kappaB</protein> ) regulation .


DZA inhibits the transcriptional activity of NF-kappaB through the hindrance of p65 ( Rel-A ) phosphorylation without reduction of its nuclear translocation and DNA binding activity .

DZA inhibits the transcriptional activity of <protein>NF-kappaB</protein> through the hindrance of <protein>p65</protein> ( <protein>Rel-A</protein> ) phosphorylation without reduction of its nuclear translocation and DNA binding activity .


The inhibitory effect of DZA on NF-kappaB transcriptional activity is potentiated by the addition of homocysteine .

The inhibitory effect of DZA on <protein>NF-kappaB</protein> transcriptional activity is potentiated by the addition of homocysteine .


Taken together , DZA promotes the proteolytic degradation of IkappaBalpha , but not IkappaBbeta , resulting in an increase of DNA binding activity of NF-kappaB in the nucleus in the absence of its transcriptional activity in RAW 264.7 cells .

Taken together , DZA promotes the proteolytic degradation of <protein>IkappaBalpha</protein> , but not <protein>IkappaBbeta</protein> , resulting in an increase of DNA binding activity of <protein>NF-kappaB</protein> in the nucleus in the absence of its transcriptional activity in <cell_line>RAW 264.7 cells</cell_line> .


The reduction of IkappaBalpha by DZA is neither involved in IkappaB kinase complex activation nor modulated by the addition of homocysteine .

The reduction of <protein>IkappaBalpha</protein> by DZA is neither involved in <protein>IkappaB kinase complex</protein> activation nor modulated by the addition of homocysteine .


This study strongly suggests that DZA may be a potent drug for the treatment of diseases in which NF-kappaB plays a central pathogenic role , as well as a useful tool for studying the regulation and physiological functions of NF-kappaB .

This study strongly suggests that DZA may be a potent drug for the treatment of diseases in which <protein>NF-kappaB</protein> plays a central pathogenic role , as well as a useful tool for studying the regulation and physiological functions of <protein>NF-kappaB</protein> .


The role of gamma/delta T cell receptor positive cells in pregnancy .

The role of <cell_type>gamma/delta T cell receptor positive cells</cell_type> in pregnancy .


PROBLEM : Due to the lack of classical HLA antigens on the trophoblast , fetal antigens are possibly presented in a non major histocompatibility complex ( MHC ) restricted way .

PROBLEM : Due to the lack of <protein>classical HLA antigens</protein> on the trophoblast , <protein>fetal antigens</protein> are possibly presented in a non <protein>major histocompatibility complex</protein> ( <protein>MHC</protein> ) restricted way .


Decidual gammadelta T cells , which significantly increase in number during pregnancy , might play a role in recognition of fetal antigens and also in determining the quality of the response to these antigens .

<cell_type>Decidual gammadelta T cells</cell_type> , which significantly increase in number during pregnancy , might play a role in recognition of <protein>fetal antigens</protein> and also in determining the quality of the response to these <protein>antigens</protein> .


Our study was aimed at investigating the role of this cell population in progesterone-dependent immunomodulation .


METHOD OF STUDY : Peripheral lymphocytes from healthy pregnant women and from habitual aborters were tested by immunocytochemistry for the presence of gamma/delta T cell receptor ( TCR ) and progesterone receptor .

METHOD OF STUDY : <cell_type>Peripheral lymphocytes</cell_type> from healthy pregnant women and from habitual aborters were tested by immunocytochemistry for the presence of gamma/delta T cell receptor ( TCR ) and progesterone receptor .


To investigate the effect of treatment with a pan anti gamma/delta antibody , lymphocytes were incubated for 3 hr with the antibody , and then interleukin ( IL ) -10 , IL-12 and progesterone-induced blocking factor ( PIBF ) expression ( by immuno-cytochemistry ) as well as natural killer ( NK ) cell activity were determined .

To investigate the effect of treatment with a pan <protein>anti gamma/delta antibody</protein> , <cell_type>lymphocytes</cell_type> were incubated for 3 hr with the antibody , and then <protein>interleukin ( IL ) -10</protein> , <protein>IL-12</protein> and <protein>progesterone-induced blocking factor</protein> ( <protein>PIBF</protein> ) expression ( by immuno-cytochemistry ) as well as <cell_type>natural killer ( NK ) cell</cell_type> activity were determined .


RESULTS : In peripheral blood of healthy pregnant women the percentage of gamma/delta TCR+ cells was significantly higher ( P < 0.001 ) than in that of recurrent aborters or of non-pregnant individuals .

RESULTS : In peripheral blood of healthy pregnant women the percentage of <cell_type>gamma/delta TCR+ cells</cell_type> was significantly higher ( P < 0.001 ) than in that of recurrent aborters or of non-pregnant individuals .


Ninety-seven percent of gamma/delta TCR+ pregnancy lymphocytes expressed progesterone receptor .

Ninety-seven percent of <cell_type>gamma/delta TCR+ pregnancy lymphocytes</cell_type> expressed <protein>progesterone receptor</protein> .


Binding of a specific antibody to the gamma/delta TCR inhibited PIBF -as well as IL-10 production , whereas it increased NK activity and IL-12 expression .

Binding of a specific antibody to the gamma/delta TCR inhibited PIBF -as well as IL-10 production , whereas it increased NK activity and <protein>IL-12</protein> expression .


CONCLUSIONS : These data suggest the role of gamma/delta TCR-bearing lymphocytes in progesterone-dependent immunomodulation .

CONCLUSIONS : These data suggest the role of <cell_type>gamma/delta TCR-bearing lymphocytes</cell_type> in progesterone-dependent immunomodulation .


Monocyte adhesion and spreading on human endothelial cells is dependent on Rho -regulated receptor clustering .

Monocyte adhesion and spreading on <cell_type>human endothelial cells</cell_type> is dependent on <protein>Rho</protein> -regulated receptor clustering .


The GTPase Rho is known to mediate the assembly of integrin-containing focal adhesions and actin stress fibers .

The <protein>GTPase</protein> <protein>Rho</protein> is known to mediate the assembly of integrin-containing focal adhesions and actin stress fibers .


Here , we investigate the role of Rho in regulating the distribution of the monocyte-binding receptors E-selectin , ICAM-1 , and VCAM-1 in human endothelial cells .

Here , we investigate the role of <protein>Rho</protein> in regulating the distribution of the <protein>monocyte-binding receptors</protein> <protein>E-selectin</protein> , <protein>ICAM-1</protein> , and <protein>VCAM-1</protein> in <cell_type>human endothelial cells</cell_type> .


Inhibition of Rho activity with C3 transferase or N19RhoA , a dominant negative RhoA mutant , reduced the adhesion of monocytes to activated endothelial cells and inhibited their spreading .

Inhibition of <protein>Rho</protein> activity with <protein>C3 transferase</protein> or <protein>N19RhoA</protein> , a dominant negative <protein>RhoA mutant</protein> , reduced the adhesion of <cell_type>monocytes</cell_type> to activated <cell_type>endothelial cells</cell_type> and inhibited their spreading .


Similar effects were observed after pretreatment of endothelial cells with cytochalasin D .

Similar effects were observed after pretreatment of <cell_type>endothelial cells</cell_type> with cytochalasin D .


In contrast , dominant negative Rac and Cdc42 proteins did not affect monocyte adhesion or spreading .

In contrast , <protein>dominant negative Rac and Cdc42 proteins</protein> did not affect monocyte adhesion or spreading .


C3 transferase and cytochalasin D did not alter the expression levels of monocyte-binding receptors on endothelial cells , but did inhibit clustering of E-selectin , ICAM-1 , and VCAM-1 on the cell surface induced by monocyte adhesion or cross-linking antibodies .

C3 transferase and cytochalasin D did not alter the expression levels of <protein>monocyte-binding receptors</protein> on <cell_type>endothelial cells</cell_type> , but did inhibit clustering of <protein>E-selectin</protein> , <protein>ICAM-1</protein> , and <protein>VCAM-1</protein> on the cell surface induced by monocyte adhesion or <protein>cross-linking antibodies</protein> .


Similarly , N19RhoA inhibited receptor clustering .

Similarly , <protein>N19RhoA</protein> inhibited receptor clustering .


Monocyte adhesion and receptor cross-linking induced stress fiber assembly , and inhibitors of myosin light chain kinase prevented this response but did not affect receptor clustering .

Monocyte adhesion and receptor cross-linking induced stress fiber assembly , and inhibitors of <protein>myosin light chain kinase</protein> prevented this response but did not affect receptor clustering .


Finally , receptor clusters colocalized with ezrin/moesin/radixin proteins .

Finally , receptor clusters colocalized with <protein>ezrin/moesin/radixin proteins</protein> .


These results suggest that Rho is required in endothelial cells for the assembly of stable adhesions with monocytes via the clustering of monocyte-binding receptors and their association with the actin cytoskeleton , independent of stress fiber formation .

These results suggest that <protein>Rho</protein> is required in <cell_type>endothelial cells</cell_type> for the assembly of stable adhesions with <cell_type>monocytes</cell_type> via the clustering of <protein>monocyte-binding receptors</protein> and their association with the actin cytoskeleton , independent of stress fiber formation .


Selection of the T cell repertoire .


Advances in gene technology have allowed the manipulation of molecular interactions that shape the T cell repertoire .


Although recognized as fundamental aspects of T lymphocyte development , only recently have the mechanisms governing positive and negative selection been examined at a molecular level .

Although recognized as fundamental aspects of <cell_type>T lymphocyte</cell_type> development , only recently have the mechanisms governing positive and negative selection been examined at a molecular level .


Positive selection refers to the active process of rescuing MHC-restricted thymocytes from programmed cell death .

Positive selection refers to the active process of rescuing <cell_type>MHC-restricted thymocytes</cell_type> from programmed cell death .


Negative selection refers to the deletion or inactivation of potentially autoreactive thymocytes .

Negative selection refers to the deletion or inactivation of potentially <cell_type>autoreactive thymocytes</cell_type> .


This review focuses on interactions during thymocyte maturation that define the T cell repertoire , with an emphasis placed on current literature within this field .

This review focuses on interactions during <cell_type>thymocyte</cell_type> maturation that define the T cell repertoire , with an emphasis placed on current literature within this field .


CD28 costimulation augments IL-2 secretion of activated lamina propria T cells by increasing mRNA stability without enhancing IL-2 gene transactivation .

<protein>CD28</protein> costimulation augments <protein>IL-2</protein> secretion of activated lamina propria T cells by increasing mRNA stability without enhancing <protein>IL-2</protein> gene transactivation .


The pathways leading to activation in lamina propria ( LP ) T cells are different from peripheral T cells .

The pathways leading to activation in <cell_type>lamina propria ( LP ) T cells</cell_type> are different from <cell_type>peripheral T cells</cell_type> .


LP T cells exhibit enhanced IL-2 secretion when activated through the CD2 pathway .

<cell_type>LP T cells</cell_type> exhibit enhanced <protein>IL-2</protein> secretion when activated through the <protein>CD2</protein> pathway .


Coligation of CD28 leads to synergistic enhancement of IL-2 secretion .

Coligation of <protein>CD28</protein> leads to synergistic enhancement of <protein>IL-2</protein> secretion .


Previous studies have characterized the CD28 augmentation of TCR -mediated signaling in peripheral blood T cells through transcriptional activation of an IL-2 promoter CD28 response element ( CD28RE ) , along with enhanced mRNA stability .

Previous studies have characterized the <protein>CD28</protein> augmentation of <protein>TCR</protein> -mediated signaling in <cell_type>peripheral blood T cells</cell_type> through transcriptional activation of an <protein>IL-2</protein> promoter <dna>CD28 response element</dna> ( <dna>CD28RE</dna> ) , along with enhanced mRNA stability .


This study characterized molecular events involved in CD28 costimulation of IL-2 production in LP mononuclear cells ( LPMC ) .

This study characterized molecular events involved in <protein>CD28</protein> costimulation of <protein>IL-2</protein> production in <cell_type>LP mononuclear cells ( LPMC )</cell_type> .


LPMC exhibited increased IL-2 production in response to CD28 costimulation , compared with cells activated through CD2 alone .

<cell_type>LPMC</cell_type> exhibited increased <protein>IL-2</protein> production in response to <protein>CD28</protein> costimulation , compared with cells activated through <protein>CD2</protein> alone .


IL-2 secretion was paralleled by increased expression of IL-2 mRNA , resulting from enhanced IL-2 mRNA stability .

<protein>IL-2</protein> secretion was paralleled by increased expression of <rna>IL-2 mRNA</rna> , resulting from enhanced <rna>IL-2 mRNA</rna> stability .


In contrast to transcriptional activation in PBMC , EMSA revealed that CD28 coligation of CD2-activated LPMC does not result in increased binding of trans-factors to the CD28RE , nor did Western blots detect changes in I-kappaBalpha or I-kappaBbeta levels following CD28 coligation .

In contrast to transcriptional activation in <cell_type>PBMC</cell_type> , EMSA revealed that <protein>CD28</protein> coligation of <cell_type>CD2-activated LPMC</cell_type> does not result in increased binding of trans-factors to the <dna>CD28RE</dna> , nor did Western blots detect changes in <protein>I-kappaBalpha</protein> or <protein>I-kappaBbeta</protein> levels following <protein>CD28</protein> coligation .


Furthermore , CD28 coligation fails to enhance IL-2 promoter-reporter or RE/AP construct expression in CD2-activated LPMC .

Furthermore , <protein>CD28</protein> coligation fails to enhance <dna>IL-2 promoter-reporter</dna> or <protein>RE/AP</protein> construct expression in <cell_type>CD2-activated LPMC</cell_type> .


The results reported herein indicate that the molecular mechanisms involved in CD28 cosignaling and regulation of IL-2 secretion in LP T cells are unique to that compartment and differ from those seen in peripheral blood T cells .

The results reported herein indicate that the molecular mechanisms involved in <protein>CD28</protein> cosignaling and regulation of <protein>IL-2</protein> secretion in <cell_type>LP T cells</cell_type> are unique to that compartment and differ from those seen in <cell_type>peripheral blood T cells</cell_type> .


These observations suggest a biological significance for different mechanisms of IL-2 activation in initiation and maintenance of the cytokine repertoire found in the mucosa .

These observations suggest a biological significance for different mechanisms of <protein>IL-2</protein> activation in initiation and maintenance of the <protein>cytokine repertoire</protein> found in the mucosa .


Expression of Th1 and Th2 type cytokines responding to HBsAg and HBxAg in chronic hepatitis B patients .

Expression of <protein>Th1 and Th2 type cytokines</protein> responding to <protein>HBsAg</protein> and <protein>HBxAg</protein> in chronic hepatitis B patients .


The cytokine pattern on viral antigen recognition is believed to exert a profound influence on the resolution of viral infections and viral clearance .

The <protein>cytokine pattern</protein> on viral antigen recognition is believed to exert a profound influence on the resolution of viral infections and viral clearance .


This study was initiated to investigate whether a cytokine imbalance oriented toward Th2 type response plays a role in chronic hepatitis B .

This study was initiated to investigate whether a <protein>cytokine</protein> imbalance oriented toward Th2 type response plays a role in chronic hepatitis B .


Cytokine profiles of peripheral blood mononuclear cells associated with chronic hepatitis B were analysed by RT-PCR .

<protein>Cytokine profiles</protein> of <cell_type>peripheral blood mononuclear cells</cell_type> associated with chronic hepatitis B were analysed by RT-PCR .


Upon HBsAg stimulation , expression of IFN-gamma , IL-2 , IL-4 , and IL-10 was detected in 41 % , 8 % , 41 % , and 50 % of the patients , respectively .

Upon <protein>HBsAg</protein> stimulation , expression of <protein>IFN-gamma</protein> , <protein>IL-2</protein> , <protein>IL-4</protein> , and <protein>IL-10</protein> was detected in 41 % , 8 % , 41 % , and 50 % of the patients , respectively .


Among these cytokines , the expression of IFN-gamma was associated with high levels of serum AST/ALT .

Among these <protein>cytokines</protein> , the expression of <protein>IFN-gamma</protein> was associated with high levels of <protein>serum AST/ALT</protein> .


However , we could not prove that Th2 type cytokines had a protective effect on hepatocytes .

However , we could not prove that <protein>Th2 type cytokines</protein> had a protective effect on <cell_type>hepatocytes</cell_type> .


Upon HBxAg stimulation , there was no recognizable association of cytokine patterns with AST/ALT levels .

Upon <protein>HBxAg</protein> stimulation , there was no recognizable association of <protein>cytokine patterns</protein> with AST/ALT levels .


In conclusion , production of a Th1 cytokine , IFN-gamma , by HBsAg -reactive cells was associated with hepatocyte damage in chronic hepatitis B , while no counteracting effect of Th2 cytokines produced by those cells was observed .

In conclusion , production of a <protein>Th1 cytokine</protein> , <protein>IFN-gamma</protein> , by <protein>HBsAg</protein> -reactive cells was associated with hepatocyte damage in chronic hepatitis B , while no counteracting effect of <protein>Th2 cytokines</protein> produced by those cells was observed .


Apoptosis and growth inhibition in malignant lymphocytes after treatment with arsenic trioxide at clinically achievable concentrations [ see comments ]

Apoptosis and growth inhibition in <cell_type>malignant lymphocytes</cell_type> after treatment with arsenic trioxide at clinically achievable concentrations [ see comments ]


BACKGROUND : Arsenic trioxide ( As2O3 ) can induce clinical remission in patients with acute promyelocytic leukemia via induction of differentiation and programmed cell death ( apoptosis ) .


We investigated the effects of As2O3 on a panel of malignant lymphocytes to determine whether growth-inhibitory and apoptotic effects of As2O3 can be observed in these cells at clinically achievable concentrations .

We investigated the effects of As2O3 on a panel of <cell_type>malignant lymphocytes</cell_type> to determine whether growth-inhibitory and apoptotic effects of As2O3 can be observed in these cells at clinically achievable concentrations .


METHODS : Eight malignant lymphocytic cell lines and primary cultures of lymphocytic leukemia and lymphoma cells were treated with As2O3 , with or without dithiothreitol ( DTT ) or buthionine sulfoximine ( BSO ) ( an inhibitor of glutathione synthesis ) .

METHODS : Eight <cell_line>malignant lymphocytic cell lines</cell_line> and <cell_line>primary cultures</cell_line> of <cell_type>lymphocytic leukemia and lymphoma cells</cell_type> were treated with As2O3 , with or without dithiothreitol ( DTT ) or buthionine sulfoximine ( BSO ) ( an inhibitor of glutathione synthesis ) .


Apoptosis was assessed by cell morphology , flow cytometry , annexin V protein level , and terminal deoxynucleotidyl transferase labeling of DNA fragments .

Apoptosis was assessed by cell morphology , flow cytometry , annexin V protein level , and <protein>terminal deoxynucleotidyl transferase</protein> labeling of <dna>DNA fragments</dna> .


Cellular proliferation was determined by 5-bromo-2'-deoxyuridine incorporation into DNA and flow cytometry and by use of a mitotic arrest assay .


Mitochondrial transmembrane potential ( delta psi ( m ) ) was measured by means of rhodamine 123 staining and flow cytometry .


Protein expression was assessed by western blot analysis or immunofluorescence .


RESULTS : Therapeutic concentrations of As2O3 ( 1-2 microM ) had dual effects on malignant lymphocytes : 1 ) inhibition of growth through adenosine triphosphate ( ATP ) depletion and prolongation of cell cycle time and 2 ) induction of apoptosis .

RESULTS : Therapeutic concentrations of As2O3 ( 1-2 microM ) had dual effects on <cell_type>malignant lymphocytes</cell_type> : 1 ) inhibition of growth through adenosine triphosphate ( ATP ) depletion and prolongation of cell cycle time and 2 ) induction of apoptosis .


As2O3-induced apoptosis was preceded by delta psi ( m ) collapse .


DTT antagonized and BSO enhanced As2O3-induced ATP depletion , delta psi ( m ) collapse , and apoptosis .


Caspase-3 activation , usually resulting from delta psi ( m ) collapse , was not always associated with As2O3-induced apoptosis .

<protein>Caspase-3</protein> activation , usually resulting from delta psi ( m ) collapse , was not always associated with As2O3-induced apoptosis .


As2O3 induced PML ( promyelocytic leukemia ) protein degradation but did not modulate expression of cell cycle-related proteins , including c-myc , retinoblastoma protein , cyclin-dependent kinase 4 , cyclin D1 , and p53 , or expression of differentiation-related antigens .

As2O3 induced PML ( promyelocytic leukemia ) protein degradation but did not modulate expression of <protein>cell cycle-related proteins</protein> , including <protein>c-myc</protein> , <protein>retinoblastoma protein</protein> , <protein>cyclin-dependent kinase 4</protein> , <protein>cyclin D1</protein> , and <protein>p53</protein> , or expression of <protein>differentiation-related antigens</protein> .


CONCLUSIONS : Substantial growth inhibition and apoptosis without evidence of differentiation were induced in most malignant lymphocytic cells treated with 1-2 microM As2O3 .

CONCLUSIONS : Substantial growth inhibition and apoptosis without evidence of differentiation were induced in most <cell_type>malignant lymphocytic cells</cell_type> treated with 1-2 microM As2O3 .


As2O3 may prove useful in the treatment of malignant lymphoproliferative disorders .


Control of cell cycle entry and apoptosis in B lymphocytes infected by Epstein-Barr virus .

Control of cell cycle entry and apoptosis in <cell_type>B lymphocytes</cell_type> infected by Epstein-Barr virus .


Infection of human B cells with Epstein-Barr virus ( EBV ) results in activation of the cell cycle and cell growth .

Infection of <cell_type>human B cells</cell_type> with Epstein-Barr virus ( EBV ) results in activation of the cell cycle and cell growth .


To interpret the mechanisms by which EBV activates the cell , we have assayed many proteins involved in control of the G0 and G1 phases of the cell cycle and regulation of apoptosis .


In EBV infection most of the changes , including the early induction of cyclin D2 , are dependent on expression of EBV genes , but an alteration in the E2F-4 profile was partly independent of viral gene expression , presumably occurring in response to signal transduction activated when the virus binds to its receptor , CD21 .

In EBV infection most of the changes , including the early induction of <protein>cyclin D2</protein> , are dependent on expression of <dna>EBV genes</dna> , but an alteration in the <protein>E2F-4</protein> profile was partly independent of viral gene expression , presumably occurring in response to signal transduction activated when the virus binds to its receptor , <protein>CD21</protein> .


By comparing the expression of genes controlling apoptosis , including those encoding several members of the BCL-2 family of proteins , the known relative resistance of EBV-immortalized B-cell lines to apoptosis induced by low serum was found to correlate with expression of both BCL-2 and A20 .

By comparing the expression of genes controlling apoptosis , including those encoding several members of the <protein>BCL-2 family</protein> of proteins , the known relative resistance of <cell_line>EBV-immortalized B-cell lines</cell_line> to apoptosis induced by low serum was found to correlate with expression of both <protein>BCL-2</protein> and <protein>A20</protein> .


A20 can be regulated by the NF-kappaB transcription factor , which is known to be activated by the EBV LMP-1 protein .

A20 can be regulated by the <protein>NF-kappaB</protein> <protein>transcription factor</protein> , which is known to be activated by the <protein>EBV LMP-1 protein</protein> .


Quantitative assays demonstrated a direct temporal relationship between LMP-1 protein levels and active NF-kappaB during the time course of infection .

Quantitative assays demonstrated a direct temporal relationship between <protein>LMP-1 protein</protein> levels and active <protein>NF-kappaB</protein> during the time course of infection .


CTLA-4 -Mediated inhibition of early events of T cell proliferation .

<protein>CTLA-4</protein> -Mediated inhibition of early events of T cell proliferation .


CTLA-4 engagement by mAbs inhibits , while CD28 enhances , IL-2 production and proliferation upon T cell activation .

<protein>CTLA-4</protein> engagement by <protein>mAbs</protein> inhibits , while <protein>CD28</protein> enhances , <protein>IL-2</protein> production and proliferation upon T cell activation .


Here , we have analyzed the mechanisms involved in CTLA-4 -mediated inhibition of T cell activation of naive CD4+ T cells using Ab cross-linking .

Here , we have analyzed the mechanisms involved in <protein>CTLA-4</protein> -mediated inhibition of T cell activation of naive <cell_type>CD4+ T cells</cell_type> using Ab cross-linking .


CTLA-4 ligation inhibited CD3/ CD28 -induced IL-2 mRNA accumulation by inhibiting IL-2 transcription , which appears to be mediated in part through decreasing NF-AT accumulation in the nuclei .

<protein>CTLA-4</protein> ligation inhibited CD3/ <protein>CD28</protein> -induced <rna>IL-2 mRNA</rna> accumulation by inhibiting <protein>IL-2</protein> transcription , which appears to be mediated in part through decreasing <protein>NF-AT</protein> accumulation in the nuclei .


However , CTLA-4 ligation did not appear to affect the CD28 -mediated stabilization of IL-2 mRNA .

However , <protein>CTLA-4</protein> ligation did not appear to affect the <protein>CD28</protein> -mediated stabilization of <rna>IL-2 mRNA</rna> .


Further , CTLA-4 engagement inhibited progression through the cell cycle by inhibiting the production of cyclin D3 , cyclin-dependent kinase ( cdk ) 4 , and cdk6 when the T cells were stimulated with anti-CD3/CD28 and with anti-CD3 alone .

Further , <protein>CTLA-4</protein> engagement inhibited progression through the cell cycle by inhibiting the production of <protein>cyclin D3</protein> , <protein>cyclin-dependent kinase</protein> <protein>( cdk ) 4</protein> , and <protein>cdk6</protein> when the <cell_type>T cells</cell_type> were stimulated with <protein>anti-CD3/CD28</protein> and with <protein>anti-CD3</protein> alone .


These results indicate that CTLA-4 signaling inhibits events early in T cell activation both at IL-2 transcription and at the level of IL-2 -independent events of the cell cycle , and does not simply oppose CD28 -mediated costimulation .

These results indicate that <protein>CTLA-4</protein> signaling inhibits events early in T cell activation both at <protein>IL-2</protein> transcription and at the level of <protein>IL-2</protein> -independent events of the cell cycle , and does not simply oppose <protein>CD28</protein> -mediated costimulation .


The glucocorticoid receptor cooperates with the erythropoietin receptor and c-Kit to enhance and sustain proliferation of erythroid progenitors in vitro .

The <protein>glucocorticoid receptor</protein> cooperates with the <protein>erythropoietin receptor</protein> and <protein>c-Kit</protein> to enhance and sustain proliferation of <cell_type>erythroid progenitors</cell_type> in vitro .


Although erythropoietin ( Epo ) is essential for the production of mature red blood cells , the cooperation with other factors is required for a proper balance between progenitor proliferation and differentiation .

Although <protein>erythropoietin</protein> ( <protein>Epo</protein> ) is essential for the production of <cell_type>mature red blood cells</cell_type> , the cooperation with other factors is required for a proper balance between progenitor proliferation and differentiation .


In avian erythroid progenitors , steroid hormones cooperate with tyrosine kinase receptors to induce renewal of erythroid progenitors .

In avian <cell_type>erythroid progenitors</cell_type> , steroid hormones cooperate with <protein>tyrosine kinase receptors</protein> to induce renewal of <cell_type>erythroid progenitors</cell_type> .


We examined the role of corticosteroids in the in vitro expansion of primary human erythroid cells in liquid cultures and colony assays .

We examined the role of corticosteroids in the in vitro expansion of <cell_type>primary human erythroid cells</cell_type> in liquid cultures and colony assays .


Dexamethasone ( Dex ) , a synthetic glucocorticoid hormone , cooperated with Epo and stem cell factor to induce erythroid progenitors to undergo 15 to 22 cell divisions , corresponding to a 10 ( 5 ) - to 10 ( 6 ) -fold amplification of erythroid cells .

Dexamethasone ( Dex ) , a synthetic glucocorticoid hormone , cooperated with <protein>Epo</protein> and <protein>stem cell factor</protein> to induce <cell_type>erythroid progenitors</cell_type> to undergo 15 to 22 cell divisions , corresponding to a 10 ( 5 ) - to 10 ( 6 ) -fold amplification of <cell_type>erythroid cells</cell_type> .


Dex acted directly on erythroid progenitors and maintained the colony-forming capacity of the progenitor cells expanded in liquid cultures .

Dex acted directly on <cell_type>erythroid progenitors</cell_type> and maintained the colony-forming capacity of the <cell_type>progenitor cells</cell_type> expanded in <cell_line>liquid cultures</cell_line> .


The hormone delayed terminal differentiation into erythrocytes , which was assayed by morphology , hemoglobin accumulation , and the expression of genes characteristic for immature cells .

The hormone delayed terminal differentiation into <cell_type>erythrocytes</cell_type> , which was assayed by morphology , <protein>hemoglobin</protein> accumulation , and the expression of genes characteristic for <cell_type>immature cells</cell_type> .


Sustained proliferation of erythroid progenitors could be induced equally well from purified erythroid burst-forming units ( BFU-E ) , from CD34 ( + ) blast cells , and from bone marrow depleted from CD34 ( + ) cells .

Sustained proliferation of <cell_type>erythroid progenitors</cell_type> could be induced equally well from <cell_line>purified erythroid burst-forming units</cell_line> ( <cell_line>BFU-E</cell_line> ) , from <cell_type>CD34 ( + ) blast cells</cell_type> , and from bone marrow depleted from <cell_type>CD34 ( + ) cells</cell_type> .


NF-kappaB functions as both a proapoptotic and antiapoptotic regulatory factor within a single cell type .

<protein>NF-kappaB</protein> functions as both a <protein>proapoptotic and antiapoptotic regulatory factor</protein> within a single cell type .


Recently NF-kappaB has been shown to have both proapoptotic and antiapoptotic functions .

Recently <protein>NF-kappaB</protein> has been shown to have both proapoptotic and antiapoptotic functions .


In T cell hybridomas , both T cell activators and glucocorticoids induce apoptosis .

In <cell_line>T cell hybridomas</cell_line> , both T cell activators and glucocorticoids induce apoptosis .


Here we show that blockade of NF-kappaB activity , using a dominant negative IkappaBalpha , has opposite effects on these two apoptotic signals .

Here we show that blockade of <protein>NF-kappaB</protein> activity , using a <protein>dominant negative IkappaBalpha</protein> , has opposite effects on these two apoptotic signals .


Treatment with PMA plus ionomycin ( P/I ) results in the upregulation of Fas Ligand ( FasL ) and induction of apoptosis .

Treatment with PMA plus ionomycin ( P/I ) results in the upregulation of <protein>Fas Ligand</protein> ( <protein>FasL</protein> ) and induction of apoptosis .


Inhibition of NF-kappaB activity inhibits the P/I mediated induction of FasL mRNA and decreases the level of apoptosis in these cultures , thus establishing NF-kappaB as a proapoptotic factor in this context .

Inhibition of <protein>NF-kappaB</protein> activity inhibits the P/I mediated induction of <rna>FasL mRNA</rna> and decreases the level of apoptosis in these cultures , thus establishing <protein>NF-kappaB</protein> as a <protein>proapoptotic factor</protein> in this context .


Conversely , inhibition of NF-kappaB confers a tenfold increase in glucocorticoid mediated apoptosis , establishing that NF-kappaB also functions as an antiapoptotic factor .

Conversely , inhibition of <protein>NF-kappaB</protein> confers a tenfold increase in glucocorticoid mediated apoptosis , establishing that <protein>NF-kappaB</protein> also functions as an antiapoptotic factor .


We conclude that NF-kappaB is a context-dependent apoptosis regulator .

We conclude that <protein>NF-kappaB</protein> is a context-dependent apoptosis regulator .


Our data suggests that NF-kappaB may function as an antiapoptotic factor in thymocytes while functioning as a proapoptotic factor in mature peripheral T cells .

Our data suggests that <protein>NF-kappaB</protein> may function as an antiapoptotic factor in <cell_type>thymocytes</cell_type> while functioning as a proapoptotic factor in <cell_type>mature peripheral T cells</cell_type> .


SOCS-3 is tyrosine phosphorylated in response to interleukin-2 and suppresses STAT5 phosphorylation and lymphocyte proliferation .

<protein>SOCS-3</protein> is tyrosine phosphorylated in response to <protein>interleukin-2</protein> and suppresses <protein>STAT5</protein> phosphorylation and lymphocyte proliferation .


Members of the recently discovered SOCS/CIS/SSI family have been proposed as regulators of cytokine signaling , and while targets and mechanisms have been suggested for some family members , the precise role of these proteins remains to be defined .

Members of the recently discovered <protein>SOCS/CIS/SSI family</protein> have been proposed as regulators of <protein>cytokine</protein> signaling , and while targets and mechanisms have been suggested for some family members , the precise role of these proteins remains to be defined .


To date no SOCS proteins have been specifically implicated in interleukin-2 ( IL-2 ) signaling in T cells .

To date no <protein>SOCS proteins</protein> have been specifically implicated in <protein>interleukin-2</protein> ( <protein>IL-2</protein> ) signaling in <cell_type>T cells</cell_type> .


Here we report SOCS-3 expression in response to IL-2 in both T-cell lines and human peripheral blood lymphocytes .

Here we report <protein>SOCS-3</protein> expression in response to <protein>IL-2</protein> in both <cell_line>T-cell lines</cell_line> and <cell_type>human peripheral blood lymphocytes</cell_type> .


SOCS-3 protein was detectable as early as 30 min following IL-2 stimulation , while CIS was seen only at low levels after 2 h .

<protein>SOCS-3</protein> protein was detectable as early as 30 min following <protein>IL-2</protein> stimulation , while <protein>CIS</protein> was seen only at low levels after 2 h .


Unlike CIS , SOCS-3 was rapidly tyrosine phosphorylated in response to IL-2 .

Unlike <protein>CIS</protein> , <protein>SOCS-3</protein> was rapidly tyrosine phosphorylated in response to <protein>IL-2</protein> .


Tyrosine phosphorylation of SOCS-3 was observed upon coexpression with Jak1 and Jak2 but only weakly with Jak3 .

Tyrosine phosphorylation of <protein>SOCS-3</protein> was observed upon coexpression with <protein>Jak1</protein> and <protein>Jak2</protein> but only weakly with <protein>Jak3</protein> .


In these experiments , SOCS-3 associated with Jak1 and inhibited Jak1 phosphorylation , and this inhibition was markedly enhanced by the presence of IL-2 receptor beta chain ( IL-2Rbeta ) .

In these experiments , <protein>SOCS-3</protein> associated with <protein>Jak1</protein> and inhibited <protein>Jak1</protein> phosphorylation , and this inhibition was markedly enhanced by the presence of <protein>IL-2 receptor beta chain</protein> ( <protein>IL-2Rbeta</protein> ) .


Moreover , following IL-2 stimulation of T cells , SOCS-3 was able to interact with the IL-2 receptor complex , and in particular tyrosine phosphorylated Jak1 and IL-2Rbeta .

Moreover , following <protein>IL-2</protein> stimulation of <cell_type>T cells</cell_type> , <protein>SOCS-3</protein> was able to interact with the <protein>IL-2 receptor complex</protein> , and in particular <protein>tyrosine phosphorylated Jak1</protein> and <protein>IL-2Rbeta</protein> .


Additionally , in lymphocytes expressing SOCS-3 but not CIS , IL-2 -induced tyrosine phosphorylation of STAT5b was markedly reduced , while there was only a weak effect on IL-3-mediated STAT5b tyrosine phosphorylation .

Additionally , in <cell_type>lymphocytes</cell_type> expressing <protein>SOCS-3</protein> but not <protein>CIS</protein> , <protein>IL-2</protein> -induced tyrosine phosphorylation of <protein>STAT5b</protein> was markedly reduced , while there was only a weak effect on <protein>IL-3-mediated STAT5b</protein> tyrosine phosphorylation .


Finally , proliferation induced by both IL-2 -and IL-3 was significantly inhibited in the presence of SOCS-3 .

Finally , proliferation induced by both <protein>IL-2</protein> -and <protein>IL-3</protein> was significantly inhibited in the presence of <protein>SOCS-3</protein> .


The findings suggest that when SOCS-3 is rapidly induced by IL-2 in T cells , it acts to inhibit IL-2 responses in a classical negative feedback loop .

The findings suggest that when <protein>SOCS-3</protein> is rapidly induced by <protein>IL-2</protein> in <cell_type>T cells</cell_type> , it acts to inhibit <protein>IL-2</protein> responses in a classical negative feedback loop .


Human alveolar macrophages are markedly deficient in REF-1 and AP-1 DNA binding activity .

<cell_type>Human alveolar macrophages</cell_type> are markedly deficient in <protein>REF-1</protein> and <protein>AP-1</protein> DNA binding activity .


Although many functions of human alveolar macrophages are altered compared with their precursor cell , the blood monocyte ( monocyte ) , the reason ( s ) for these functional changes have not been determined .

Although many functions of <cell_type>human alveolar macrophages</cell_type> are altered compared with their <cell_type>precursor cell</cell_type> , the <cell_type>blood monocyte</cell_type> ( <cell_type>monocyte</cell_type> ) , the reason ( s ) for these functional changes have not been determined .


We recently reported that human alveolar macrophages do not express AP-1 DNA binding activity ( Monick , M. M. , Carter , A. B. , Gudmundsson , G. , Geist , L. J. , and Hunninghake , G. W. ( 1998 ) Am. J. Physiol. 275 , L389-L397 ) .

We recently reported that <cell_type>human alveolar macrophages</cell_type> do not express <protein>AP-1</protein> DNA binding activity ( Monick , M. M. , Carter , A. B. , Gudmundsson , G. , Geist , L. J. , and Hunninghake , G. W. ( 1998 ) Am. J. Physiol. 275 , L389-L397 ) .


To determine why alveolar macrophages do not express AP-1 DNA binding activity , we first showed that there was not a decrease in expression of the FOS and JUN proteins that make up the AP-1 complex .

To determine why <cell_type>alveolar macrophages</cell_type> do not express <protein>AP-1</protein> DNA binding activity , we first showed that there was not a decrease in expression of the <protein>FOS and JUN proteins</protein> that make up the <protein>AP-1</protein> complex .


There was , however , a significant difference in the amounts of the nuclear protein , REF-1 ( which regulates AP-1 DNA binding by altering the redox status of FOS and JUN proteins ) , in alveolar macrophages compared with monocytes .

There was , however , a significant difference in the amounts of the <protein>nuclear protein</protein> , <protein>REF-1</protein> ( which regulates <protein>AP-1</protein> DNA binding by altering the redox status of <protein>FOS</protein> and <protein>JUN proteins</protein> ) , in <cell_type>alveolar macrophages</cell_type> compared with <cell_type>monocytes</cell_type> .


In addition , in vitro differentiation of monocytes to a macrophage-like cell resulted in decreased amounts of REF-1 .

In addition , in vitro differentiation of <cell_type>monocytes</cell_type> to a <cell_type>macrophage-like cell</cell_type> resulted in decreased amounts of <protein>REF-1</protein> .


Finally , addition of REF-1 from activated monocytes to alveolar macrophage nuclear proteins resulted in a marked increase in AP-1 DNA binding .

Finally , addition of <protein>REF-1</protein> from <cell_type>activated monocytes</cell_type> to alveolar macrophage nuclear proteins resulted in a marked increase in <protein>AP-1</protein> DNA binding .


These studies strongly suggest that the process of differentiation of monocytes into alveolar macrophages is associated with a loss of REF-1 and AP-1 activity .

These studies strongly suggest that the process of differentiation of <cell_type>monocytes</cell_type> into <cell_type>alveolar macrophages</cell_type> is associated with a loss of <protein>REF-1</protein> and <protein>AP-1</protein> activity .


This observation may explain , in part , some of the functional differences observed for alveolar macrophages compared with monocytes .

This observation may explain , in part , some of the functional differences observed for <cell_type>alveolar macrophages</cell_type> compared with <cell_type>monocytes</cell_type> .


Development and maturation of secondary lymphoid tissues .


The secondary lymphoid tissues are located at strategic sites where foreign antigens can be efficiently brought together with immune system regulatory and effector cells .

The secondary lymphoid tissues are located at strategic sites where <protein>foreign antigens</protein> can be efficiently brought together with <cell_type>immune system regulatory and effector cells</cell_type> .


The organized structure of the secondary lymphoid tissues is thought to enhance the sensitivity of antigen recognition and to support proper regulation of the activation and maturation of the antigen-responsive lymphoid cells .

The organized structure of the secondary lymphoid tissues is thought to enhance the sensitivity of antigen recognition and to support proper regulation of the activation and maturation of the <cell_type>antigen-responsive lymphoid cells</cell_type> .


Although a substantial amount is known about the cellular elements that compose the lymphoid and nonlymphoid components of the secondary lymphoid tissues , information concerning the signals that control the development of the tissues and that maintain the organized tissue microenvironment remain undefined .

Although a substantial amount is known about the <dna>cellular elements</dna> that compose the lymphoid and nonlymphoid components of the secondary lymphoid tissues , information concerning the signals that control the development of the tissues and that maintain the organized tissue microenvironment remain undefined .


Studies over the past few years have identified lymphotoxin as a critical signaling molecule not only for the organogenesis of secondary lymphoid tissues but for the maintenance of aspects of their microarchitecture as well .


Additional signaling molecules that contribute to the formation of normal lymphoid tissue structure are being identified at an accelerating pace .


Analyses of mouse strains with congenital defects in different aspects of secondary lymphoid tissue development are beginning to clarify the role of these tissues in immune responses and host defense .


This review focuses on studies defining recently identified crucial signals for the biogenesis of secondary lymphoid organs and for the maintenance of their proper microarchitecture .


It also discusses new insights into how the structure of these tissues supports effective immune responses .


Modulation of CD28 expression : distinct regulatory pathways during activation and replicative senescence .

Modulation of <protein>CD28</protein> expression : distinct regulatory pathways during activation and replicative senescence .


The costimulatory molecule CD28 has a restricted tissue distribution and is expressed on T cells and some plasmacytoma cells .

The <protein>costimulatory molecule</protein> <protein>CD28</protein> has a restricted tissue distribution and is expressed on <cell_type>T cells</cell_type> and some <cell_type>plasmacytoma cells</cell_type> .


Although CD28 is constitutively expressed , its expression is transiently down-regulated following T cell activation and declines progressively with in vitro senescence .

Although <protein>CD28</protein> is constitutively expressed , its expression is transiently down-regulated following T cell activation and declines progressively with in vitro senescence .


In vivo , CD8+ T cells and , less frequently , CD4+ T cells may completely lose CD28 surface expression during chronic infections and with aging .

In vivo , <cell_type>CD8+ T cells</cell_type> and , less frequently , <cell_type>CD4+ T cells</cell_type> may completely lose <protein>CD28</protein> surface expression during chronic infections and with aging .


This correlates with changes of nuclear protein-binding activities to two motifs , site alpha and beta , within the CD28 minimal promoter .

This correlates with changes of nuclear protein-binding activities to two motifs , <protein>site alpha and beta</protein> , within the <dna>CD28 minimal promoter</dna> .


Both alpha- and beta-bound complexes are found only in lymphoid tissues , in CD28+ T cells , and in some transformed B cells .

Both alpha- and beta-bound complexes are found only in lymphoid tissues , in <cell_type>CD28+ T cells</cell_type> , and in some <cell_line>transformed B cells</cell_line> .


These complexes are coordinately expressed except during replicative senescence , which is characterized by the down-modulation of site beta -but not site alpha -binding activities .

These complexes are coordinately expressed except during replicative senescence , which is characterized by the down-modulation of <protein>site beta</protein> -but not <protein>site alpha</protein> -binding activities .


In contrast , T cell activation induces a parallel decline in both site alpha- and beta-binding activities .


CD4+ and CD8+ T cells differ in their beta-binding profiles , which may explain the more pronounced down-regulation of CD28 in senescent CD8+ T cells .

CD4+ and <cell_type>CD8+ T cells</cell_type> differ in their beta-binding profiles , which may explain the more pronounced down-regulation of <protein>CD28</protein> in senescent <cell_type>CD8+ T cells</cell_type> .


In vivo expanded CD4+CD28null and CD8+CD28null T cells uniformly lack alpha- and beta- bound complexes , resembling the pattern seen in chronically activated cells and not of senescent cells .

In vivo expanded <cell_line>CD4+CD28null and CD8+CD28null T cells</cell_line> uniformly lack <protein>alpha- and beta- bound complexes</protein> , resembling the pattern seen in <cell_type>chronically activated cells</cell_type> and not of <cell_type>senescent cells</cell_type> .


A role for RanBP1 in the release of CRM1 from the nuclear pore complex in a terminal step of nuclear export .

A role for <protein>RanBP1</protein> in the release of <protein>CRM1</protein> from the <protein>nuclear pore complex</protein> in a terminal step of nuclear export .


We recently developed an assay in which nuclear export of the shuttling transcription factor NFAT ( nuclear factor of activated T cells ) can be reconstituted in permeabilized cells with the GTPase Ran and the nuclear export receptor CRM1 .

We recently developed an assay in which nuclear export of the shuttling <protein>transcription factor NFAT</protein> ( <protein>nuclear factor of activated T cells</protein> ) can be reconstituted in permeabilized cells with the <protein>GTPase</protein> <protein>Ran</protein> and the nuclear export receptor <protein>CRM1</protein> .


We have now used this assay to identify another export factor .


After preincubation of permeabilized cells with a Ran mutant that can not hydrolyze GTP ( RanQ69L ) , cytosol supports NFAT export , but CRM1 and Ran alone do not .

After preincubation of <cell_line>permeabilized cells</cell_line> with a <protein>Ran mutant</protein> that can not hydrolyze GTP ( <protein>RanQ69L</protein> ) , cytosol supports <protein>NFAT</protein> export , but <protein>CRM1</protein> and <protein>Ran</protein> alone do not .


The RanQ69L preincubation leads to accumulation of CRM1 at the cytoplasmic periphery of the nuclear pore complex ( NPC ) in association with the p62 complex and Can/Nup214 .

The <protein>RanQ69L</protein> preincubation leads to accumulation of <protein>CRM1</protein> at the cytoplasmic periphery of the <protein>nuclear pore complex</protein> ( <protein>NPC</protein> ) in association with the <protein>p62 complex</protein> and Can/Nup214 .


Ran GTP-dependent association of CRM1 with these nucleoporins was reconstituted in vitro .

<protein>Ran</protein> GTP-dependent association of <protein>CRM1</protein> with these <protein>nucleoporins</protein> was reconstituted in vitro .


By biochemical fractionation and reconstitution , we showed that RanBP1 restores nuclear export after the RanQ69L preincubation .

By biochemical fractionation and reconstitution , we showed that <protein>RanBP1</protein> restores nuclear export after the <protein>RanQ69L</protein> preincubation .


It also stimulates nuclear export in cells that have not been preincubated with RanQ69L .

It also stimulates nuclear export in cells that have not been preincubated with <protein>RanQ69L</protein> .


RanBP1 as well as Ran-binding domains of the cytoplasmic nucleoporin RanBP2 promote the release of CRM1 from the NPC .

<protein>RanBP1</protein> as well as <protein>Ran-binding domains</protein> of the <protein>cytoplasmic nucleoporin</protein> <protein>RanBP2</protein> promote the release of <protein>CRM1</protein> from the <protein>NPC</protein> .


Taken together , our results indicate that Ran GTP is important for the targeting of export complexes to the cytoplasmic side of the NPC and that RanBP1 and probably RanBP2 are involved in the dissociation of nuclear export complexes from the NPC in a terminal step of transport .

Taken together , our results indicate that <protein>Ran</protein> GTP is important for the targeting of export complexes to the cytoplasmic side of the <protein>NPC</protein> and that <protein>RanBP1</protein> and probably <protein>RanBP2</protein> are involved in the dissociation of <protein>nuclear export complexes</protein> from the <protein>NPC</protein> in a terminal step of transport .


c-Myc and E1A induced cellular sensitivity to activated NK cells involves cytotoxic granules as death effectors .

<protein>c-Myc</protein> and <protein>E1A</protein> induced cellular sensitivity to <cell_type>activated NK cells</cell_type> involves cytotoxic granules as death effectors .


The contact of natural killer ( NK ) cells with foreign cells and with certain virus-infected or tumor cells triggers the cytolytic machinery of NK cells .

The contact of <cell_type>natural killer ( NK ) cells</cell_type> with <cell_type>foreign cells</cell_type> and with certain <cell_type>virus-infected or tumor cells</cell_type> triggers the cytolytic machinery of <cell_type>NK cells</cell_type> .


This triggering leads to exocytosis of the cytotoxic NK cell granules .

This triggering leads to exocytosis of the <cell_type>cytotoxic NK cell granules</cell_type> .


The oncoproteins c-Myc and E1A render cells vulnerable to NK cell mediated cytolysis yet the mechanisms of sensitization are not well understood .

The <protein>oncoproteins</protein> <protein>c-Myc</protein> and <protein>E1A</protein> render cells vulnerable to NK cell mediated cytolysis yet the mechanisms of sensitization are not well understood .


In a model where foreign cells ( rat fibroblasts ) were cocultured with human IL-2 activated NK cells , we observed that NK cells were capable of efficiently killing their targets only if the cells overexpressed the oncogene c-Myc or E1A .

In a model where <cell_type>foreign cells</cell_type> ( <cell_type>rat fibroblasts</cell_type> ) were cocultured with <cell_type>human IL-2 activated NK cells</cell_type> , we observed that <cell_type>NK cells</cell_type> were capable of efficiently killing their targets only if the cells overexpressed the oncogene <protein>c-Myc</protein> or <protein>E1A</protein> .


Both the parental and the oncogene expressing fibroblasts similarly triggered phosphoinositide hydrolysis in the bound NK cells , demonstrating that NK cells were cytolytically activated in contact with both resistant parental and oncogene expressing sensitive target fibroblasts .

Both the parental and the <cell_type>oncogene expressing fibroblasts</cell_type> similarly triggered phosphoinositide hydrolysis in the bound <cell_type>NK cells</cell_type> , demonstrating that <cell_type>NK cells</cell_type> were cytolytically activated in contact with both resistant parental and <cell_type>oncogene expressing sensitive target fibroblasts</cell_type> .


The cell death was independent of wild-type p53 and was not inhibited by an anti-apoptotic protein EIB19K .

The cell death was independent of <protein>wild-type p53</protein> and was not inhibited by an <protein>anti-apoptotic protein EIB19K</protein> .


These results provided evidence that c-Myc and E1A activated the NK cell induced cytolysis at a post-triggering stage of NK cell-target cell interaction .

These results provided evidence that <protein>c-Myc</protein> and <protein>E1A</protein> activated the NK cell induced cytolysis at a post-triggering stage of NK cell-target cell interaction .


In consistence , the c-Myc and E1A overexpressing fibroblasts were more sensitive to the cytolytic effects of isolated NK cell-derived granules than parental cells .

In consistence , the <protein>c-Myc</protein> and <protein>E1A</protein> overexpressing <cell_type>fibroblasts</cell_type> were more sensitive to the cytolytic effects of isolated NK cell-derived granules than <cell_type>parental cells</cell_type> .


The data indicate that oncogenes activate the cytotoxicity of NK cell granules .

The data indicate that <dna>oncogenes</dna> activate the cytotoxicity of NK cell granules .


This mechanism can have a role in directing the cytolytic action of NK cells towards the virus-infected and cancer cells .

This mechanism can have a role in directing the cytolytic action of <cell_type>NK cells</cell_type> towards the <cell_type>virus-infected and cancer cells</cell_type> .


Unicellular-unilineage erythropoietic cultures : molecular analysis of regulatory gene expression at sibling cell level .

<cell_line>Unicellular-unilineage erythropoietic cultures</cell_line> : molecular analysis of regulatory gene expression at sibling cell level .


In vitro studies on hematopoietic control mechanisms have been hampered by the heterogeneity of the analyzed cell populations , ie , lack of lineage specificity and developmental stage homogeneity of progenitor/precursor cells growing in culture .

In vitro studies on hematopoietic control mechanisms have been hampered by the heterogeneity of the analyzed cell populations , ie , lack of lineage specificity and developmental stage homogeneity of <cell_type>progenitor/precursor cells</cell_type> growing in culture .


We developed unicellular culture systems for unilineage differentiation of purified hematopoietic progenitor cells followed by daughter cell analysis at cellular and molecular level .

We developed unicellular culture systems for unilineage differentiation of <cell_type>purified hematopoietic progenitor cells</cell_type> followed by daughter cell analysis at cellular and molecular level .


In the culture system reported here , ( 1 ) the growth factor ( GF ) stimulus induces cord blood ( CB ) progenitor cells to proliferate and differentiate/mature exclusively along the erythroid lineage ; ( 2 ) this erythropoietic wave is characterized by less than 4 % apoptotic cells ; ( 3 ) asymmetric divisions are virtually absent , ie , nonresponsive hematopoietic progenitors with no erythropoietic potential are forced into apoptosis ; ( 4 ) the system is cell division controlled ( cdc ) , ie , the number of divisions performed by each cell is monitored .

In the culture system reported here , ( 1 ) the <protein>growth factor</protein> ( <protein>GF</protein> ) stimulus induces <cell_type>cord blood ( CB ) progenitor cells</cell_type> to proliferate and differentiate/mature exclusively along the <cell_type>erythroid lineage</cell_type> ; ( 2 ) this erythropoietic wave is characterized by less than 4 % apoptotic cells ; ( 3 ) asymmetric divisions are virtually absent , ie , nonresponsive <cell_type>hematopoietic progenitors</cell_type> with no erythropoietic potential are forced into apoptosis ; ( 4 ) the system is cell division controlled ( cdc ) , ie , the number of divisions performed by each cell is monitored .


Single-cell reverse transcriptase -polymerase chain reaction ( RT-PCR ) analysis was applied to this culture system to investigate gene expression of diverse receptors , markers of differentiation , and transcription factors ( EKLF , GATA-1 , GATA-2 , p45 NF-E2 , PU.1 , and SCL/Tal1 ) at discrete stages of erythropoietic development .

Single-cell <protein>reverse transcriptase</protein> -polymerase chain reaction ( RT-PCR ) analysis was applied to this culture system to investigate gene expression of diverse <protein>receptors</protein> , <protein>markers of differentiation</protein> , and <protein>transcription factors</protein> ( <protein>EKLF</protein> , <protein>GATA-1</protein> , <protein>GATA-2</protein> , <protein>p45 NF-E2</protein> , <protein>PU.1</protein> , and <protein>SCL/Tal1</protein> ) at discrete stages of erythropoietic development .


Freshly isolated CD34 ( + ) cells expressed CD34 , c-kit , PU.1 , and GATA-2 but did not express CD36 , erythropoietin receptor ( EpoR ) , SCL/Tal1 , EKLF , NF-E2 , GATA-1 , or glyocophorin A ( GPA ) .

Freshly isolated <cell_type>CD34 ( + ) cells</cell_type> expressed <protein>CD34</protein> , <protein>c-kit</protein> , <protein>PU.1</protein> , and <protein>GATA-2</protein> but did not express <protein>CD36</protein> , <protein>erythropoietin receptor</protein> ( <protein>EpoR</protein> ) , <protein>SCL/Tal1</protein> , <protein>EKLF</protein> , NF-E2 , <protein>GATA-1</protein> , or <protein>glyocophorin A</protein> ( <protein>GPA</protein> ) .


In early to intermediate stages of erythroid differentiation we monitored the induction of CD36 , Tal1 , EKLF , NF-E2 , and GATA-1 that preceeded expression of EpoR .

In early to intermediate stages of erythroid differentiation we monitored the induction of <protein>CD36</protein> , <protein>Tal1</protein> , <protein>EKLF</protein> , <protein>NF-E2</protein> , and <protein>GATA-1</protein> that preceeded expression of <protein>EpoR</protein> .


In late stages of erythroid maturation , GPA was upregulated , whereas CD34 , c-kit , PU.1 , and GATA-2 were barely or not detected .

In late stages of erythroid maturation , <protein>GPA</protein> was upregulated , whereas <protein>CD34</protein> , <protein>c-kit</protein> , <protein>PU.1</protein> , and <protein>GATA-2</protein> were barely or not detected .


In addition , competitive single-cell RT-PCR was used to assay CD34 mRNA transcripts in sibling CD34 ( + ) CD38 ( - ) cells differentiating in unilineage erythroid cultures : this analysis allowed us to semiquantitate the gradual downmodulation of CD34 mRNA from progenitor cells through their differentiating erythroid progeny .

In addition , competitive single-cell RT-PCR was used to assay <rna>CD34 mRNA transcripts</rna> in <cell_line>sibling CD34 ( + ) CD38 ( - ) cells</cell_line> differentiating in <cell_line>unilineage erythroid cultures</cell_line> : this analysis allowed us to semiquantitate the gradual downmodulation of <rna>CD34 mRNA</rna> from <cell_type>progenitor cells</cell_type> through their <cell_line>differentiating erythroid progeny</cell_line> .


It is concluded that this novel culture system , coupled with single-cell RT-PCR analysis , may eliminate the ambiguities intrinsic to molecular studies on heterogeneous populations of hematopoietic progenitors/precursors growing in culture , particularly in the initial stages of development .

It is concluded that this novel culture system , coupled with single-cell RT-PCR analysis , may eliminate the ambiguities intrinsic to molecular studies on heterogeneous populations of <cell_type>hematopoietic progenitors/precursors</cell_type> growing in culture , particularly in the initial stages of development .


Differences in phosphorylation of the IL-2R associated JAK/STAT proteins between HTLV-I ( + ) , IL-2-independent and IL-2-dependent cell lines and uncultured leukemic cells from patients with adult T-cell lymphoma/leukemia .

Differences in phosphorylation of the <protein>IL-2R associated JAK/STAT proteins</protein> between <cell_line>HTLV-I ( + ) , IL-2-independent and IL-2-dependent cell lines</cell_line> and <cell_type>uncultured leukemic cells</cell_type> from patients with adult T-cell lymphoma/leukemia .


To determine activation status of the IL-2R -associated ( Jak/STAT ) pathway in the HTLV-I infected cells , we examined tyrosine phosphorylation of Jak3 , STAT3 , and STAT5 in several HTLV-I ( + ) T-cell lines and in uncultured leukemic T cells isolated from patients with adult T-cell lymphoma/leukemia ( ATLL ) .

To determine activation status of the <protein>IL-2R</protein> -associated ( <protein>Jak/STAT</protein> ) pathway in the <cell_line>HTLV-I infected cells</cell_line> , we examined tyrosine phosphorylation of <protein>Jak3</protein> , <protein>STAT3</protein> , and <protein>STAT5</protein> in several <cell_line>HTLV-I ( + ) T-cell lines</cell_line> and in <cell_type>uncultured leukemic T cells</cell_type> isolated from patients with adult T-cell lymphoma/leukemia ( ATLL ) .


Constitutive basal phosphorylation of Jak3 and , usually , STAT3 and STAT5 was detected in all four IL-2-independent cell lines tested , but in none of the three IL-2-dependent cell lines .

Constitutive basal phosphorylation of <protein>Jak3</protein> and , usually , <protein>STAT3</protein> and <protein>STAT5</protein> was detected in all four <cell_line>IL-2-independent cell lines</cell_line> tested , but in none of the three <cell_line>IL-2-dependent cell lines</cell_line> .


Similarly , there was no detectable basal phosphorylation of Jak3 and STAT5 in the leukemic cells from ATLL patients ( 0/8 and 0/3 , respectively ) .

Similarly , there was no detectable basal phosphorylation of <protein>Jak3</protein> and <protein>STAT5</protein> in the <cell_type>leukemic cells</cell_type> from ATLL patients ( 0/8 and 0/3 , respectively ) .


However , stimulation with IL-2 resulted in Jak3 and STAT5 phosphorylation in both leukemic ATLL cells and IL-2-dependent lines .

However , stimulation with <protein>IL-2</protein> resulted in <protein>Jak3</protein> and <protein>STAT5</protein> phosphorylation in both <cell_type>leukemic ATLL cells</cell_type> and <cell_line>IL-2-dependent lines</cell_line> .


Furthermore , expression of SHP-1 phosphatase which is a negative regulator of cytokine receptor signaling , was lost in most IL-2 independent cell lines ( 3/4 ) but not in the leukemic ATLL cells ( 0/3 ) .

Furthermore , expression of <protein>SHP-1 phosphatase</protein> which is a negative regulator of <protein>cytokine receptor</protein> signaling , was lost in most <cell_line>IL-2 independent cell lines</cell_line> ( 3/4 ) but not in the leukemic <cell_type>ATLL cells</cell_type> ( 0/3 ) .


Finally , the HTLV-I ( + ) T-cell lines ( 313 ) but not the control , HTLV-I ( - ) T-cell lines were resistant to rapamycin and its novel analog RAD .

Finally , the <cell_line>HTLV-I ( + ) T-cell lines</cell_line> ( 313 ) but not the control , <cell_line>HTLV-I ( - ) T-cell lines</cell_line> were resistant to rapamycin and its novel analog RAD .


We conclude that ( 1 ) HTLV-I infection per se does not result in a constitutive phosphorylation of the Jak3 , STAT3 , and STAT5 proteins ; ( 2 ) malignant transformation in at least some cases of ATLL does not require the constitutive , but may require IL-2 -induced , activation of the IL-2R Jak/STAT pathway ; and ( 3 ) there are major differences in T-cell immortalization mechanism ( s ) which appear to involve SHP-1 and target molecules for rapamycin and RAD .

We conclude that ( 1 ) HTLV-I infection per se does not result in a constitutive phosphorylation of the <protein>Jak3</protein> , <protein>STAT3</protein> , and <protein>STAT5</protein> proteins ; ( 2 ) malignant transformation in at least some cases of ATLL does not require the constitutive , but may require <protein>IL-2</protein> -induced , activation of the <protein>IL-2R</protein> <protein>Jak/STAT</protein> pathway ; and ( 3 ) there are major differences in T-cell immortalization mechanism ( s ) which appear to involve <protein>SHP-1</protein> and target molecules for rapamycin and RAD .


Clonality analysis using X-chromosome inactivation at the human androgen receptor gene ( Humara ) .

Clonality analysis using <dna>X-chromosome</dna> inactivation at the <dna>human androgen receptor gene</dna> ( <dna>Humara</dna> ) .


Evaluation of large cohorts of patients with chronic myeloproliferative diseases , secondary neutrophilia , and reactive thrombocytosis .


Chronic myeloproliferative diseases ( MPDs ) are not associated with consistent cytogenetic or molecular abnormalities .


Demonstration of clonal cell growth by analysis of X-chromosome inactivation ( XCI ) patterns in females provides a promising tool for diagnosis .

Demonstration of clonal cell growth by analysis of <dna>X-chromosome</dna> inactivation ( XCI ) patterns in females provides a promising tool for diagnosis .


However , this technique can be complicated by excessive lyonization of normal cells mimicking clonal cell growth : We analyzed XCI patterns at the human androgen receptor ( HUMARA ) locus in 146 healthy females , 65 women with secondary neutrophilia , 31 women with reactive thrombocytosis , and 86 women with chronic MPDs .

However , this technique can be complicated by excessive lyonization of normal cells mimicking clonal cell growth : We analyzed XCI patterns at the <dna>human androgen receptor ( HUMARA ) locus</dna> in 146 healthy females , 65 women with secondary neutrophilia , 31 women with reactive thrombocytosis , and 86 women with chronic MPDs .


A skewed XCI pattern with greater than 75 % amplification of 1 allele ( allele ratio > 3 : 1 ) was found in 22 ( 9.1 % ) of 242 control subjects .

A skewed XCI pattern with greater than 75 % amplification of 1 <dna>allele</dna> ( <dna>allele</dna> ratio > 3 : 1 ) was found in 22 ( 9.1 % ) of 242 control subjects .


The incidence of skewing was statistically significantly lower in women younger than 30 years ( 2/73 ) compared with women older than 60 years ( 10/53 ) .


Of 86 patients with a chronic MPD , 71 ( 82 % ) exhibited an allele ratio greater than 3 : 1 , whereas only 10 ( 12 % ) of 86 age-matched control subjects showed a skewed XCI pattern .

Of 86 patients with a chronic MPD , 71 ( 82 % ) exhibited an <dna>allele</dna> ratio greater than 3 : 1 , whereas only 10 ( 12 % ) of 86 age-matched control subjects showed a skewed XCI pattern .


Although statistical evaluation of the data showed a significant difference between patients with a chronic MPD and control subjects , proof of clonality in individual , especially elderly , patients is difficult .


GATA-1 and erythropoietin cooperate to promote erythroid cell survival by regulating bcl-xL expression .

<protein>GATA-1</protein> and <protein>erythropoietin</protein> cooperate to promote erythroid cell survival by regulating <protein>bcl-xL</protein> expression .


The transcription factor GATA-1 is essential for normal erythropoiesis .

The <protein>transcription factor</protein> <protein>GATA-1</protein> is essential for normal erythropoiesis .


By examining in vitro-differentiated embryonic stem cells , we showed previously that in the absence of GATA-1 , committed erythroid precursors fail to complete maturation and instead undergo apoptosis .

By examining in <cell_line>vitro-differentiated embryonic stem cells</cell_line> , we showed previously that in the absence of <protein>GATA-1</protein> , <cell_line>committed erythroid precursors</cell_line> fail to complete maturation and instead undergo apoptosis .


The mechanisms by which GATA-1 controls cell survival are unknown .

The mechanisms by which <protein>GATA-1</protein> controls cell survival are unknown .


Here we report that in erythroid cells , GATA-1 strongly induces the expression of the anti-apoptotic protein bcl-xL , but not the related proteins bcl-2 and mcl-1 .

Here we report that in <cell_type>erythroid cells</cell_type> , <protein>GATA-1</protein> strongly induces the expression of the <protein>anti-apoptotic protein</protein> <protein>bcl-xL</protein> , but not the related proteins <protein>bcl-2</protein> and <protein>mcl-1</protein> .


Consistent with a role for bcl-xL in mediating GATA-1 -induced erythroid cell survival , in vitro-differentiated bcl-xL-/- embryonic stem cells fail to generate viable mature definitive erythroid cells , a phenotype resembling that of GATA-1 gene disruption .

Consistent with a role for <protein>bcl-xL</protein> in mediating <protein>GATA-1</protein> -induced erythroid cell survival , in <cell_line>vitro-differentiated bcl-xL-/- embryonic stem cells</cell_line> fail to generate viable mature definitive <cell_type>erythroid cells</cell_type> , a phenotype resembling that of <dna>GATA-1 gene</dna> disruption .


In addition , we show that erythropoietin , which is also required for erythroid cell survival , cooperates with GATA-1 to stimulate bcl-xL gene expression and to maintain erythroid cell viability during terminal maturation .

In addition , we show that <protein>erythropoietin</protein> , which is also required for erythroid cell survival , cooperates with <protein>GATA-1</protein> to stimulate <protein>bcl-xL</protein> gene expression and to maintain erythroid cell viability during terminal maturation .


Together , our data show that bcl-xL is essential for normal erythroid development and suggest a regulatory hierarchy in which bcl-xL is a critical downstream effector of GATA-1 and erythropoietin -mediated signals .

Together , our data show that <protein>bcl-xL</protein> is essential for normal erythroid development and suggest a regulatory hierarchy in which <protein>bcl-xL</protein> is a critical downstream effector of <protein>GATA-1</protein> and <protein>erythropoietin</protein> -mediated signals .


p70 ( s6k ) integrates phosphatidylinositol 3-kinase and rapamycin-regulated signals for E2F regulation in T lymphocytes .

<protein>p70 ( s6k )</protein> integrates <protein>phosphatidylinositol 3-kinase</protein> and rapamycin-regulated signals for <protein>E2F</protein> regulation in <cell_type>T lymphocytes</cell_type> .