Molecular Identification of an MHC Class Ib (H2-Q9) Restricted T Cell Receptor Specific for a Mouse Polyomavirus Peptide VP2.139

The murine major his to compatibility complex (MHC) class Ib region encodes more than 20proteins with diverse biological functions, and many have not been characterized. Evidence emerging in recent years indicates that MHC class Ib?restricted CD8 T cells can play an important role in antiviral immunity. We molecularly cloned an α?β T cell receptor (TCR) from a T cell hydridoma cell line, that is restricted by an MHC class Ib molecule H2?Q9, and specifically recognizes the VP2.139 peptide epitope from mouse polyoma virus (PyV). We further demonstrated that the cloned TCR, using TCRα10 and TCRβ4 genes, is functional and mediates the development of Q9?VP2.139?restricted CD8 T cells in vivo. The cloning of a H2?Q9?restricted, PyV?specific α?β TCR provides a useful tool for future study of the potential role of MHC class Ib restricted CD8 T cells in antiviral immunity.