Recent studies showed that injection of interleukin (IL)-12 prevents ultraviolet (UV) light mediated @entity1155 of contact @entity56 and breaks UV-induced hapten specific tolerance. UV-mediated @entity1155 can be adoptively transferred by injecting splenocytes from UV-irradiated @entity19 ; however, @entity1155 is not transferable when donor @entity19 are treated with IL-12 after UV-irradiation. This study was performed to elucidate the mechanisms by which IL-12 counteracts this immunosuppression. To characterize the cells transferring @entity1155 , depletion studies were performed revealing that UV-induced @entity1155 is transferred via CD8+ T cells. To investigate whether IL-12 counteracts UV-induced @entity1155 by either inhibiting the development of CD8+ suppressor T cells or inducing @entity1961 + effector T cells, splenocytes from @entity19 , which were IL-12 treated and sensitized through UV-exposed skin, were depleted from @entity1961 + T cells and transferred into naive @entity19 that were subsequently sensitized. Whereas transfer of splenocytes from UV-irradiated @entity19 inhibited sensitization of recipients, no inhibition was observed after transfer of splenocytes from UV-exposed and IL-12 treated @entity19 . Recipients that received @entity1961 depleted spleen cells from UV-exposed and IL-12 treated donors, were still fully sensitizable. IL-12 also blocked transfer of UV-induced @entity1155 when it was injected into UV-exposed donor animals at a time point when suppressor cells had already developed. @entity1961 depletion of such splenocytes did not result in a loss of the reconstitutive effect of IL-12. This suggests that IL-12 may break UV-induced tolerance not by inducing @entity1961 + effector T cells, but rather by inhibiting or inactivating suppressor T cells belonging to the CD8 subtype.

Interleukin 12 breaks ultraviolet light induced immunosuppression by affecting CD8+ rather than XXXX + T cells.

@entity19 :: ('10090', 'Species') :: ['mice'] @entity1961 :: ('12504(Tax:10090)', 'Gene') :: ['CD4'] @entity56 :: ('MESH:D004342', 'Disease') :: ['hypersensitivity'] @entity1155 :: ('MESH:D011596', 'Disease') :: ['suppression']
@entity1961 :: (12504(Tax:10090),Gene) :: ['CD4']
