An increased γδ T cell population in the intestine of thymus-leukemia antigen transgenic mice

In an approach to study thymic leukemia antigen's (TL's) function, we have developed transgenic mice that express T18(d) on virtually all somatic cells; in such mice, we initially observed changes in T cells within the thymus and lymph nodes as well as the ability of TL to undergo recognition by splenic T cells. As phase II of our study, we now present the results on the composition of gut T cell populations which may be a better measure of TL's true function. We have demonstrated an increase in the number of γδ⁺ T cells as well as the increase in γδ⁺ T cells expressing the Vγ2 chain. These cells appear to be both CD4 and CD8 negative. This suggests that TL may select for a subset of γδ T cells within the gut and bolsters earlier reports implicating an H-2T regional gene product as the major histocompatibility complex ligand for γδ⁺ T cells.