The development and functions of CD41 T cells expressing a transgenic TCR specific for an MHC-I-restricted tumor antigenic epitope

It has been reported that the ratio of CD41 to CD81 T cells has no bias in a few class I major histocompatibility complex(MHC-I)-restricted T-cell receptor(TCR)-transgenic mice specific for alloantigens or autoantigens,in which most CD41 T cells express an MHC-I-restricted TCR.In this study,we further showed that more than 50%of CD41 T cells in MHC-I-restricted P1A tumor antigen-specific TCR(P1ATCR)-transgenic mice could specifically bind to MHC-I/P1A peptide complex.P1A peptide could stimulate the transgenic CD41 T cells to proliferate and secrete both type 1 helper T cell and type 2 helper T cell cytokines.The activated CD41 T cells also showed cytotoxicity against P1A-expressing tumor cells.The analysis of TCR a-chains showed that these CD41 T cells were selected by co-expressing endogenous TCRs.Our results show that CD41 T cells from P1ATCR transgenic mice co-expressed an MHC-I-restricted transgenic TCR and another rearranged endogenous TCRs,both of which were functional.