| First Author | Qiu Q | Year | 2010 |
| Journal | J Immunol | Volume | 184 |
| Issue | 4 | Pages | 1681-9 |
| PubMed ID | 20048123 | Mgi Jnum | J:159496 |
| Mgi Id | MGI:4443176 | Doi | 10.4049/jimmunol.0900062 |
| Citation | Qiu Q, et al. (2010) CD155 is involved in negative selection and is required to retain terminally maturing CD8 T cells in thymus. J Immunol 184(4):1681-9 |
| abstractText | During their final maturation in the medulla, semimature single-positive (SP) thymocytes downregulate activation markers and subsequently exit into the periphery. Although semimature CD4(+) SP cells are sensitive to negative selection, the timing of when negative selection occurs in the CD8 lineage remains elusive. We show that the abundance of terminally matured CD8(+) SP cells in adult thymus is modulated by the genetic background. Moreover, in BALB/c mice, the frequency of terminally matured CD8(+) SP cells, but not that of CD4(+) SP cells present in thymus, varies depending on age. In mice lacking expression of the adhesion receptor CD155, a selective deficiency of mature CD8(+) SP thymocytes was observed, emerging first in adolescent animals at the age when these cells start to accumulate in wild-type thymus. Evidence is provided that the mature cells emigrate prematurely when CD155 is absent, cutting short their retention time in the medulla. Moreover, in nonmanipulated wild-type mice, semimature CD8(+) SP thymocytes are subjected to negative selection, as reflected by the diverging TCR repertoires present on semimature and mature CD8(+) T cells. In CD155-deficient animals, a shift was found in the TCR repertoire displayed by the pool of CD8(+) SP cells, demonstrating that CD155 is involved in negative selection. |
