| First Author | Nie H | Year | 2008 |
| Journal | Mol Immunol | Volume | 46 |
| Issue | 1 | Pages | 207-11 |
| PubMed ID | 18722016 | Mgi Jnum | J:141021 |
| Mgi Id | MGI:3815255 | Doi | 10.1016/j.molimm.2008.07.007 |
| Citation | Nie H, et al. (2008) SATB1 is required for CD8 coreceptor reversal. Mol Immunol 46(1):207-11 |
| abstractText | Intrathymic signals induce the differentiation of immature CD4(+)CD8(+) double positive (DP) thymocytes into mature CD4(+) or CD8(+) single positive (SP) T cells. The transcriptional mechanism by which CD8 lineage is determined is not fully understood. The best evidence, which favors the kinetic signaling/coreceptor reversal model, indicates that signaled DP thymocytes terminate CD8 transcription prior to their subsequent re-initiation of CD8 transcription and ultimate differentiation into CD8SP T cells. We and others have shown that CD8 lineage commitment is severely perturbed in mice in which expression of the transcription factor SATB1 is either conventionally knocked out or T cell-specifically knocked down. Here, we demonstrate that, as with normal thymocytes, cultured SATB1-deficient DP thymocytes inactivate CD8 coreceptor transcription following receipt of signals (PMA plus ionomycin) that mimic TCR-mediated positive selection. However, this terminated CD8 transcription is not re-initiated by signals (IL-7) conducive to CD8 differentiation in SATB1-deficient DP. We show that SATB1 specifically binds to a cis-regulatory element within the CD8 enhancer (E8(III)) known to be required for coreceptor reversal. A requirement in CD8 coreceptor reversal identifies SATB1 as an essential trans-regulator of CD8 lineage fate, whose action may be mediated via recruitment to the E8(III) DP enhancer. |
