Effective Immunization Against Cutaneous Leishmaniasis with Defined Membrane Antigens Reconstituted into Liposomes

The abundant Leishmania promastigote surface Ag gp63 and Leishmania promastigote lipophosphoglycan were reconstituted into liposomes and used as a vaccine against the agent of New World cutaneous leishmaniasis, Leishmania mexicana. The Ag were inoculated s.c., i.p., and i.v. into CBA/ca and BALB/c mice. Even at low Ag dosages, 8 to 10 micrograms/mouse, the Ag induced appreciable levels of protection. In CBA/ca mice complete protection was obtained by s.c. inoculation of antigen-containing liposomes. Protection could be transferred with T cells to naive mice. Interestingly, the Ag-containing liposomes did not cause the disease exacerbation observed in previous vaccine studies with crude parasite extracts.