CD8A and infection: On the other hand, interaction between PD-1 on Tregs from mice with chronic LMCV-infection with PD-L1 expressed on CD8+ T cells was found to contribute to their capacity to suppress CD8+ T cell functions (83) and blockade of PD-L1 has been shown to reduce the in vitro suppressive function of human tumor-infiltrating Treg (79).