Regulation of T cell cytokine production by dendritic cells

Previous work has established that the dendritic cells (DC) of mouse spleen regulate the IL-2 production. and hence the extent of proliferation, of th e CD8 T cells they activate. It is non reported here that interaction of pr imary CD8 T cells with splenic CD8(alpha-) DC induced much higher productio n of IL-3, IFN-gamma and granulocyte-macrophage colony-stimulating factor ( GM-CSF), as well as IL-2, than did interaction with CD8 alpha(+) splenic DC . Furthermore, the CD8a- DC also induced higher levels of IL-2, IL-3 and IL -IO production in primary CD4 T cells, compared with that induced by CD8 al pha(+) DC. These quantitative differences did not involve qualitative shift s in the type of cytokine produced. Interleukin-4 production remained low i n all the primary T cell cultures and restimulation experiments in secondar y cultures did not reveal any bias in the cytokine production profile. When exogenous IL-2 was added to the primary cultures to ensure equal prolifera tion in response to CD8 alpha or CD8 alpha(+) DC, the higher level of produ ction of IL-3, IFN-gamma and GM-CSF induced by CD8 alpha(-) D% was maintain ed. Thus, this general control of T cell cytokine production by splenic DC involves factors additional to those that govern activation of T cells into cell cycle.