The Leishmune®́s Nucleoside hydrolase DNA vaccine as an aid in immunotherapy of canine visceral leishmaniasis

The Nucleoside hydrolase of Leishmania donovani (NH36) is the main antigen of Leishmune®, the first licensed prophylactic vaccine against canine visceral leishmaniasis (CVL). Compared to untreated controls, mongrel dogs infected with 7 x 108 Leishmania chagasi amastigotes and treated with the NH36-DNA vaccine developed significant increases in the size and proportions of DTH reactions and NH36-specific CD4+ T cell proportions which recognized the C-terminal moiety of NH36. Increases in IgG2/IgG1 anti-NH36 antibody ratios and in CD8+ T cell counts were directed to the NH36 N-terminal. The immunotherapy treatment reduced the parasite load and loss of weight and increased dog survival time.