IDENTIFICATION OF LEISHMANIA-CHAGASI ANTIGENS RECOGNIZED BY HUMAN-LYMPHOCYTES

Preparative SDS-PAGE followed by electroelution was used to separate p roteins of Leishmania chagasi promastigotes into 67 fractions. These f ractions were tested for the ability to stimulate proliferation of per ipheral blood mononuclear cells from healthy immune donors who were tr eated previously for visceral leishmaniasis and from nonimmune control s. The proliferative responses elicited by these proteins varied among individuals. The 69-kDa protein fraction contained a fragment with se quence similarity to the 70-kDa heat-shock protein. Fragments of the 4 6- and 41-kDa fractions had sequences not present in the National Biol ogical Research Foundation data bank. These data suggest that a succes sful subunit vaccine may require multiple parasite antigens. The ident ification of antigens that elicit human T cell responses is an importa nt step toward understanding the immunology of L. chagasi infection an d ultimately in the development of a vaccine.