| First Author | Ito Y | Year | 2002 |
| Journal | J Immunol | Volume | 169 |
| Issue | 9 | Pages | 4913-9 |
| PubMed ID | 12391203 | Mgi Jnum | J:111095 |
| Mgi Id | MGI:3652965 | Doi | 10.4049/jimmunol.169.9.4913 |
| Citation | Ito Y, et al. (2002) Positive selection by the pre-TCR yields mature CD8+ T cells. J Immunol 169(9):4913-9 |
| abstractText | It has been of much interest whether there is functional redundancy between the constitutively signaling pre-Talpha/TCRbeta (pre-TCR) and ligated TCRalphabeta complexes, which independently operate the two distinct checkpoints during thymocyte development, i.e., the pre-TCR involved in beta-selection at the CD4(-)CD8(-) double-negative stage and the TCRalphabeta being crucial for positive/negative selection at the CD4(+)CD8(+) double-positive stage. We found that the pre-TCR expressed on double-positive cells in TCRalpha-deficient (TCRalpha(-/-)) mice produced a small number of mature CD8(+) T cells. Surprisingly, when pre-Talpha was overexpressed, resulting in augmentation of pre-TCR expression, there was a striking increase of the CD8(+) T cells. In addition, even in the absence of up-regulation of pre-TCR expression, a similar increase of CD8(+) T cells was also observed in TCRalpha(-/-) mice overexpressing Egr-1, which lowers the threshold of signal strength required for positive selection. In sharp contrast, the CD8(+) T cells drastically decreased in the absence of pre-Talpha on a TCRalpha(-/-) background. Thus, the pre-TCR appears to functionally promote positive selection of CD8(+) T cells. The biased production of CD8(+) T cells via the pre-TCR might also support the potential involvement of signal strength in CD4/CD8 lineage commitment. |
