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The transcription factor Ets1 is important for CD4 repression and Runx3 up-regulation during CD8 T cell differentiation in the thymus.

Zamisch M, Tian L, Grenningloh R, Xiong Y, Wildt KF, Ehlers M, Ho IC, Bosselut R - J. Exp. Med. (2009)

Bottom Line: We further show that Ets1 promotes expression of Runx3, a transcription factor important for CD8 T cell differentiation and the cessation of Cd4 gene expression.Finally, we document that Ets1 binds at least two evolutionarily conserved regions within the Runx3 gene in vivo, supporting the possibility that Ets1 directly contributes to Runx3 transcription.These findings identify Ets1 as a key player during CD8 lineage differentiation and indicate that it acts, at least in part, by promoting Runx3 expression.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
The transcription factor Ets1 contributes to the differentiation of CD8 lineage cells in the thymus, but how it does so is not understood. In this study, we demonstrate that Ets1 is required for the proper termination of CD4 expression during the differentiation of major histocompatability class 1 (MHC I)-restricted thymocytes, but not for other events associated with their positive selection, including the initiation of cytotoxic gene expression, corticomedullary migration, or thymus exit. We further show that Ets1 promotes expression of Runx3, a transcription factor important for CD8 T cell differentiation and the cessation of Cd4 gene expression. Enforced Runx3 expression in Ets1-deficient MHC I-restricted thymocytes largely rescued their impaired Cd4 silencing, indicating that Ets1 is not required for Runx3 function. Finally, we document that Ets1 binds at least two evolutionarily conserved regions within the Runx3 gene in vivo, supporting the possibility that Ets1 directly contributes to Runx3 transcription. These findings identify Ets1 as a key player during CD8 lineage differentiation and indicate that it acts, at least in part, by promoting Runx3 expression.

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Ets1−/− MHC I–restricted maturelike DP thymocytes are CD8 lineage cells. Expression of the genes encoding Thpok (Zbtb7b) and perforin (Prf1) was analyzed by real-time RT-PCR on sorted Vα2hi CD24lo CD4+CD8+ and CD4−CD8+ thymocyte populations from Ets1+/+ and Ets1−/− mice carrying the P14 TCR transgene (left three columns) and on TCRhi CD4+CD8− thymocytes from wild-type mice (right column). mRNA levels, normalized on β-actin expression in the same sample, are shown relative to those in wild-type CD4+CD8− cells (Thpok) or Ets1+/+ P14 CD4−CD8+ cells (Prf1). Bars indicate the mean values derived from triplicate determination from a single sorted population; error bars show standard deviations. Data are representative of three or more independent sorted samples for each population.
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fig4: Ets1−/− MHC I–restricted maturelike DP thymocytes are CD8 lineage cells. Expression of the genes encoding Thpok (Zbtb7b) and perforin (Prf1) was analyzed by real-time RT-PCR on sorted Vα2hi CD24lo CD4+CD8+ and CD4−CD8+ thymocyte populations from Ets1+/+ and Ets1−/− mice carrying the P14 TCR transgene (left three columns) and on TCRhi CD4+CD8− thymocytes from wild-type mice (right column). mRNA levels, normalized on β-actin expression in the same sample, are shown relative to those in wild-type CD4+CD8− cells (Thpok) or Ets1+/+ P14 CD4−CD8+ cells (Prf1). Bars indicate the mean values derived from triplicate determination from a single sorted population; error bars show standard deviations. Data are representative of three or more independent sorted samples for each population.

Mentions: Because MHC I–induced selection normally gives rise to CD8-linage cells, we examined if Ets1−/− maturelike MHC I–restricted DP thymocytes were cells that undergo CD8 differentiation and fail to silence CD4, or cells that are redirected to the CD4 lineage and fail to silence CD8. We submitted maturelike Ets1−/− P14 DP thymocytes to real-time RT-PCR analysis of mRNAs encoding the transcription factor Thpok and the cytotoxic marker perforin, normally expressed in CD4 and CD8 lineage thymocytes, respectively (Fig. 4, rightmost two columns). As expected, Ets1−/− CD8 SP thymocytes expressed perforin but no Thpok (Fig. 4, second column). Importantly, the same was true of maturelike DP thymocytes (Vα2hi CD24lo DP cells from Ets1−/− P14 transgenic mice; Fig. 4, left column), indicating that these cells had a gene expression pattern typical of CD8 lineage cells.


The transcription factor Ets1 is important for CD4 repression and Runx3 up-regulation during CD8 T cell differentiation in the thymus.

Zamisch M, Tian L, Grenningloh R, Xiong Y, Wildt KF, Ehlers M, Ho IC, Bosselut R - J. Exp. Med. (2009)

Ets1−/− MHC I–restricted maturelike DP thymocytes are CD8 lineage cells. Expression of the genes encoding Thpok (Zbtb7b) and perforin (Prf1) was analyzed by real-time RT-PCR on sorted Vα2hi CD24lo CD4+CD8+ and CD4−CD8+ thymocyte populations from Ets1+/+ and Ets1−/− mice carrying the P14 TCR transgene (left three columns) and on TCRhi CD4+CD8− thymocytes from wild-type mice (right column). mRNA levels, normalized on β-actin expression in the same sample, are shown relative to those in wild-type CD4+CD8− cells (Thpok) or Ets1+/+ P14 CD4−CD8+ cells (Prf1). Bars indicate the mean values derived from triplicate determination from a single sorted population; error bars show standard deviations. Data are representative of three or more independent sorted samples for each population.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2806616&req=5

fig4: Ets1−/− MHC I–restricted maturelike DP thymocytes are CD8 lineage cells. Expression of the genes encoding Thpok (Zbtb7b) and perforin (Prf1) was analyzed by real-time RT-PCR on sorted Vα2hi CD24lo CD4+CD8+ and CD4−CD8+ thymocyte populations from Ets1+/+ and Ets1−/− mice carrying the P14 TCR transgene (left three columns) and on TCRhi CD4+CD8− thymocytes from wild-type mice (right column). mRNA levels, normalized on β-actin expression in the same sample, are shown relative to those in wild-type CD4+CD8− cells (Thpok) or Ets1+/+ P14 CD4−CD8+ cells (Prf1). Bars indicate the mean values derived from triplicate determination from a single sorted population; error bars show standard deviations. Data are representative of three or more independent sorted samples for each population.
Mentions: Because MHC I–induced selection normally gives rise to CD8-linage cells, we examined if Ets1−/− maturelike MHC I–restricted DP thymocytes were cells that undergo CD8 differentiation and fail to silence CD4, or cells that are redirected to the CD4 lineage and fail to silence CD8. We submitted maturelike Ets1−/− P14 DP thymocytes to real-time RT-PCR analysis of mRNAs encoding the transcription factor Thpok and the cytotoxic marker perforin, normally expressed in CD4 and CD8 lineage thymocytes, respectively (Fig. 4, rightmost two columns). As expected, Ets1−/− CD8 SP thymocytes expressed perforin but no Thpok (Fig. 4, second column). Importantly, the same was true of maturelike DP thymocytes (Vα2hi CD24lo DP cells from Ets1−/− P14 transgenic mice; Fig. 4, left column), indicating that these cells had a gene expression pattern typical of CD8 lineage cells.

Bottom Line: We further show that Ets1 promotes expression of Runx3, a transcription factor important for CD8 T cell differentiation and the cessation of Cd4 gene expression.Finally, we document that Ets1 binds at least two evolutionarily conserved regions within the Runx3 gene in vivo, supporting the possibility that Ets1 directly contributes to Runx3 transcription.These findings identify Ets1 as a key player during CD8 lineage differentiation and indicate that it acts, at least in part, by promoting Runx3 expression.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
The transcription factor Ets1 contributes to the differentiation of CD8 lineage cells in the thymus, but how it does so is not understood. In this study, we demonstrate that Ets1 is required for the proper termination of CD4 expression during the differentiation of major histocompatability class 1 (MHC I)-restricted thymocytes, but not for other events associated with their positive selection, including the initiation of cytotoxic gene expression, corticomedullary migration, or thymus exit. We further show that Ets1 promotes expression of Runx3, a transcription factor important for CD8 T cell differentiation and the cessation of Cd4 gene expression. Enforced Runx3 expression in Ets1-deficient MHC I-restricted thymocytes largely rescued their impaired Cd4 silencing, indicating that Ets1 is not required for Runx3 function. Finally, we document that Ets1 binds at least two evolutionarily conserved regions within the Runx3 gene in vivo, supporting the possibility that Ets1 directly contributes to Runx3 transcription. These findings identify Ets1 as a key player during CD8 lineage differentiation and indicate that it acts, at least in part, by promoting Runx3 expression.

Show MeSH