| First Author | Fung-Leung WP | Year | 1993 |
| Journal | Eur J Immunol | Volume | 23 |
| Issue | 1 | Pages | 212-6 |
| PubMed ID | 8419174 | Mgi Jnum | J:112993 |
| Mgi Id | MGI:3664171 | Doi | 10.1002/eji.1830230133 |
| Citation | Fung-Leung WP, et al. (1993) CD8 is needed for positive selection but differentially required for negative selection of T cells during thymic ontogeny. Eur J Immunol 23(1):212-6 |
| abstractText | During thymic development, immature thymocytes expressing major histocompatibility complex (MHC) class I-restricted T cell receptors (TcR) differentiate into CD8+ T cells with cytolytic functions. To evaluate the role of CD8 in positive and negative selection during thymic ontogeny, mice rendered CD8-null by gene targeting were bred with three lines of transgenic mice expressing unique MHC class I-restricted TcR. In all three instances CD8 was required for positive selection of MHC class I-restricted transgenic T cells. The efficiency of positive selection decreased in accordance with a reduced level of CD8 expression on thymocytes. Surprisingly, there was a differential requirement for CD8 expression in negative selection of MHC class I-restricted thymocytes, depending on the antigen specificity of TcR. These observations show that CD8 is essential for positive selection but is differentially required for negative selection of MHC class I-restricted T cells. Thus thymic selection, at least for negative selection, can occur in the absence of the CD8 accessory molecule. |
