CD8A and infection: However, in our MHC-matched model, TCR2+ responses visible in the splenic lymphoid population as a whole could only be attributed to CD8+ and not CD4+ T cells, indicating that the shift in CD8+ T cells toward TCR2 in the MD-resistant line 6 was large, even though the relative contribution of CD8+ T cells to the splenic T cell pool decreased significantly during the course of infection.