Vaccination with the Leishmania infantum ribosomal proteins induces protection in BALB/c mice against Leishmania chagasi and Leishmania amazonensis challenge

Leishmania chagast and Leishmania amazonensis are the etiologic agents of different clinical forms of human leishmaniasis in South America In an attempt to select candidate antigens for a vaccine protecting against different Leishmania species the efficacy of vaccination using Leishmania ribosomal proteins and saponin as adjuvant was examined in BALB/c mice against challenge infection with both parasite species Mice vaccinated with parasite ribosomal proteins purified from Leishmania Infantum plus saponin showed a specific production of TFN-gamma IL-12 and GM-CSF after in vitro stimulation with L infantum ribosomal proteins Vaccinated mice showed a reduction in the liver and spleen parasite burdens after L chagast infection After L amazonensis challenge vaccinated mice showed a decrease of the dermal pathology and a reduction in the parasite loads in the footpad and spleen In both models, protection was correlated to an IL-12-dependent production of IFN gamma by CD4(+) and CD8(+) T cells that activate macrophages for the synthesis of NO In the protected mice a decrease in the parasite-mediated IL-4 and IL-10 responses was also observed In mice challenged with L amazonensis lower levels of anti parasite specific antibodies were detected Thus Leishmania ribosomal proteins plus saponin fits the requirements to compose a pan-Leishmania vaccine (C) 2010 Institut Pasteur Published by Elsevier Masson SAS All rights reserved