The Nucleoside hydrolase DNA vaccine VR1012NH36 in prophylactic vaccination against mice tegumentar leishmaniasis

AbstractThe VR1012NH36 DNA vaccine was immunoprophylactic and immunotherapeutic against mice visceral leishmaniasis by L.(L.) chagasi and cutaneous leishmaniasis by L. (L.) mexicana. We here evaluated the protection induced by three sc doses of FML (150μg) + saponin (100μg), or two doses of VR1012 empty plasmid (100μg) or VR1012NH36 (100μg) vaccine against the footpad L. (L.) amazonensis infection with 1 million promastigotes. After infection, the anti-FML IgG, IgG1 and IgG2a antibodies were significantly increased over the saline controls only in the FML saponin vaccinated animals. The DTH response against L.(L.) amazonesis lysate was increased by both vaccines over the saline controls before infection. Regarding the reduction of parasite lesions, at week 26 after infection, significant differences were found in the footpad swelling (ANOVA; p=0.004). Protection was measured as the reduction in footpad swelling. Considering the mean values of each group as well as the individual results, the highest protection was determined by the DNA vaccine followed by the FML saponin vaccine. The DNA vaccine induced 80.4%, the empty plasmid 26.5% and the FML vaccine, 49% of reduction (p