CD8 γδ cells: presence in the adult rat thymus and generation in vitro from CD4−/CD8 thymocytes in the presence of interleukin 2
Abstract Three to fifteen percent of peripheral T cells in adults express the recently described γδ T-cell antigen receptor (TcR) heterodimer. A small subpopulation of γδ cells express the CD8 accessory molecule. In this study, we analyzed the potential of highly purified CD4 − /CD8 − , double negative (DN) rat precursor thymocytes to give rise to γδ cells. We observed that in the presence of interleukin 2 (IL-2) and concanavalin A (ConA), both DN and CD8 cells expressing the γδ TcR were generated in vitro. We then examined the rat thymus for these cells and confirmed the presence of a previously undescribed CD8 TcR-αβ − subset in the rat thymus, expressing high levels of TcR-γ and δ messages with no detectable TcR-α transcripts, similar to the cells generated in vitro in the presence of IL-2 and ConA.