| First Author | Robey E | Year | 1994 |
| Journal | J Exp Med | Volume | 179 |
| Issue | 6 | Pages | 1997-2004 |
| PubMed ID | 7515104 | Mgi Jnum | J:19021 |
| Mgi Id | MGI:67234 | Doi | 10.1084/jem.179.6.1997 |
| Citation | Robey E, et al. (1994) Constitutive CD8 expression allows inefficient maturation of CD4+ helper T cells in class II major histocompatibility complex mutant mice. J Exp Med 179(6):1997-2004 |
| abstractText | Although mature CD4+ T cells bear T cell receptors (TCRs) that recognize class II major histocompatibility complex (MHC) and mature CD8+ T cells bear TCRs that recognize class I MHC, it is possible that the initial commitment of an immature thymocyte to a CD4 or CD8 lineage is made without regard to the specificity of the TCR. According to this model, CD4+ cells with class I TCR do not mature because the CD8 coreceptor is required for class I MHC recognition and positive selection. If this model is correct, constitutive expression of CD8 should allow CD4+ T cells with class I-specific TCRs to develop. In this report, we show that mature peripheral CD4+ cells are present in class II MHC-deficient mice that express a constitutive CD8.1 transgene. These cells share a number of properties with the major class II MHC-selected CD4 population, including the ability to express CD40 ligand upon activation. Although mature CD4 cells are also detectable in the thymus of class II MHC mutant/CD8.1 transgenic mice, they represent a small fraction of the mature CD4 cells found in mice that express class II MHC. These results indicate that some T cells choose the CD4 helper lineage independent of their antigen receptor specificity; however, the inefficiency of generating class I-specific CD4 cells leaves open the possibility that an instructive signal generated upon MHC recognition may bias lineage commitment. |
