CD8A and infection: However, the function of LFA-1/ICAM-1 interactions in CD8+ T cell differentiation and function is unclear, as blocking CD8+ T cell clustering has been shown to increase effector differentiation and IFN-γ production in vitro and following Incomplete Freund Adjuvant (IFA)-OVA priming [23], while it decreases effector differentiation [15,19] and IFN-γ production in vivo, following multiple infection and vaccination models [19].