CD8A and viral infectious disease: In human, the phenotype and functional potential of chronically stimulated CD8 T cells differ among viral infections (9).HIV-specific response is characterized by a decreased proliferative capacity of the central memory CD8 T cell pool, incomplete differentiation of effectors with reduced cytotoxic ability, and increased sensitivity to apoptosis as compared to CD8 T cells specific for non-progressive persistent infections, such as EBV or cytomegalovirus (CMV)[10,11].Several studies have suggested a particular role for the PD-1/PD-L1 pathway in the exhaustion of HIV-specific CD8 T cells.