Nanobiotechnologic approach to a promising vaccine prototype for immunisation against leishmaniasis: a fast and effective method to incorporate GPI-anchored proteins of Leishmania amazonensis into liposomes.

Liposomes are known to be a potent adjuvant for a wide range of antigens, as well as appropriate antigen carriers for antibody generation response in vivo. In addition, liposomes are effective vehicles for peptides and proteins, thus enhancing their immunogenicity. Considering these properties of liposomes and the antigenicity of the Leishmania membrane proteins, we evaluated if liposomes carrying glycosylphosphatidylinositol (GPI)-anchored proteins of Leishmania amazonensis promastigotes could induce protective immunity in BALB/c mice. To assay protective immunity, BALB/c mice were intraperitoneally injected with liposomes, GPI-protein extract (EPSGPI) as well as with the proteoliposomes carrying GPI-proteins. Mice inoculated with EPSGPI and total protein present in constitutive proteoliposomes displayed a post-infection protection of about 70% and 90%, respectively. The liposomes are able to work as adjuvant in the EPSGPI protection. These systems seem to be a promising vaccine prototype for immunisation against leishmaniasis.