To study the mode of action of a live vaccine against leishmaniasis
Leishmania major is the major cause of cutaneous leishmaniasis, an emerging disease with a yearly incidence of 2 million cases. Drug therapy is not adequate, and vaccines are not available. Inoculation of live parasites (leishmanization) has been the only strategy that has ever protected humans. Leishmanization mimics infection and clinical pathology (ulcer formation), that heals to create a chronic, latent infection that maintains immunity, but was withdrawn due to the high frequency of unacceptably large vaccinal lesions. Using mice, we have demonstrated that the co-inoculation of live Lm and immunostimulatory oligodeoxynucleotides (Lm/CpG) eliminates vaccinal lesions without compromising chronicity and the subsequent longlife immunity. Our aim is the molecular characterization of the immunological events involved in protection following Lm/CpG vaccination, and the definition of whether the same events take place when the vaccine is used therapeutically. Our long-term objective is reaching a better understanding of the mechanisms of immunity implicated in the control of persistent pathogens to design vaccines for leishmaniasis, and other chronic infections.