Non-cytotoxic, IL-4, IL-5, IL-10 producing CD8+ T cells: their activation and effector functions.

CD8+ T cells activated in the presence of IL-4 can develop into distinct, non-cytotoxic CD8- and cytotoxic CD8+ subsets that produce IL-4, IL-5, IL-10 but do not produce IFN-gamma. These 'Th2 like' CD8+ cells may enhance Th2 responses, help B cells or suppress Th1 immune responses. Importantly, the switch from the cytotoxic, IFN-gamma producing CD8+ T-cell phenotype could compromise the host response to infectious agents such as HIV.