Diversified phenotype of antigen specific CD8+ T cells responding to the immunodominant epitopes of IE and pp65 antigens of human cytomegalovirus

To study the cytomegalovirus (CMV)-specific CD8+ T cells in individuals with HLA A∗1101, A∗0201 and A∗2402, our findings showed that peptide SK-10-2, KI-10 and KV-10 of CMV IE and pp65 antigens were immunodominant in 198 individuals with HLA A∗1101, A∗0201 and A∗2402, the most frequent genotypes in Chinese. Interestingly, SK-10-2 induced the strongest T cell response to produce IFN-γ whereas the others did not induce prominent IFN-γ production despite they all induced remarkable T cell proliferation. The peptides induced different phenotypes including IFN-γhighTNF-αlow and TNF-αlowFoxp3low. It suggests that only some of CMV-reactive CD8+ T cells are real protective IFN-γhigh cytotoxic T cells.