CD4(-) CD8 T-CELL-SUBSETS CAN CONFER PROTECTION AGAINST LEISHMANIA-M-MEXICANA INFECTION(), CD8(+) AND CD4()

We studied the role of CD4(+), CD8(+), CD4(-) CD8(-) T cells and IgG a nti-leishmania alter infection or vaccination in the CBA/ca mouse. Mic e were either infected with L. m. mexicana promastigotes or vaccinated with parasite-membrane antigens incorporated into liposomes. Successf ully vaccinated mice were used as cell-donors in adoptive transfer exp eriments. Naive, syngeneic recipients received highly-enriched CD4(+), CD8(+) or CD4(-) CD8(-) T cells from those two set of donors and chal lenged with live parasites. Our results showed that both CD4(+) and CD 8(+) 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 C D4(-) CD8(-) T cells and the synthesis of IgG anti-leishmania.