CD4+, CD8+ and CD4- CD8- T cell-subsets can confer protection against Leishmania m. mexicana infection

we studied the role of cd4+, cd8+, cd4- cd8- t cells and igg anti-leishmania after infection or vaccination in the cba/ca mouse. mice were either infected with l. m. mexicana promastigotes or vaccinated with parasite-membrane antigens incorporated into liposomes. successfully vaccinated mice were used as cell-donors in adoptive transfer experiments. naive, syngeneic recipients received highly-enriched cd4+, cd8+ or cd4- cd8- t cells from those two set of donors and challenged with live parasites. our results showed that, both cd4+ and cd8+ t cells from infected or vaccinated donors conferred significant disease-resistance to naive recipients. in addition, adoptive transfer of cd4- cd8- t cells from vaccinated donors significantly delayed lesion growth in recipient mice. we concluded that vaccination of cba mice correlates with the induction of protective cd4+, cd8+ and cd4- cd8- t cells and the synthesis of igg anti-leishmania.