First Author | Reed-Loisel LM | Year | 2005 |
Journal | J Immunol | Volume | 174 |
Issue | 12 | Pages | 7746-52 |
PubMed ID | 15944277 | Mgi Jnum | J:109978 |
Mgi Id | MGI:3630196 | Doi | 10.4049/jimmunol.174.12.7746 |
Citation | Reed-Loisel LM, et al. (2005) An MHC class Ib-restricted TCR that cross-reacts with an MHC class Ia molecule. J Immunol 174(12):7746-52 |
abstractText | TCR transgenic 6C5 T cells recognize an insulin B chain epitope presented by the nonclassical class I MHC molecule, Qa-1(b). Positive selection of these T cells was shown previously to require Qa-1(b). Despite dedicated specificity for Qa-1(b), evidence presented in the current study indicates that 6C5 T cells can cross-recognize a classical class I molecule. Clonal deletion was observed unexpectedly in 6C5.H-2(bxq) mice, which do not express I-E MHC class II molecules and thus should not be subject to superantigen-mediated negative selection. 6C5 T cells were observed to respond in vivo and in vitro to spleen cells from allogeneic H-2(q) mice, and specificity was mapped to D(q). Evidence was obtained for direct recognition of D(q), rather than indirect presentation of a D(q)-derived peptide presented by Qa-1(b). Polyclonal CD8(+) T cells from class Ia-deficient K(b)D(b-/-) mice reacted in vitro to allogeneic spleen cells with an apparent frequency comparable to conventional class Ia-restricted T cells. Our results provide a clear example of a Qa-1-specific TCR that can cross-react with a class Ia molecule and evidence supporting the idea that this may be a common property of T cells selected by class Ib molecules. |