Leishmania infantum HSP70-II null mutant as candidate vaccine against leishmaniasis: A preliminary evaluation

Background: visceral leishmaniasis is the most severe form of leishmaniasis and no effective vaccine exists. the use of live attenuated vaccines is emerging as a promising vaccination strategy. results: in this study,we tested the ability of a leishmania infantum deletion mutant,lacking both hsp70-ii alleles (hsp70-ii),to provide protection against leishmania infection in the l. major-balb/c infection model. administration of the mutant line by either intraperitoneal,intravenous or subcutaneous route invariably leads to the production of high levels of no and the development in mice of type 1 immune responses,as determined by analysis of anti-leishmania igg subclasses. in addition,we have shown that hsp70-ii would be a safe live vaccine as immunodeficient scid mice,and hamsters (mesocricetus auratus),infected with mutant parasites did not develop any sign of pathology. conclusions: the results suggest that the hsp70-ii mutant is a promising and safe vaccine,but further studies in more appropriate animal models (hamsters and dogs) are needed to appraise whether this attenuate mutant would be useful as vaccine against visceral leishmaniasis. © 2011 carrián et al; licensee biomed central ltd.