Immunological changes in canine peripheral blood leukocytes triggered by immunization with first or second generation vaccines against canine visceral leishmaniasis

In this study, we summarized the major phenotypic/functional aspects of circulating leukocytes following canine immunization with Leishvaccine and Leishmune (R). Our findings showed that Leishvaccine triggered early changes in the innate immunity (neutrophils and eosinophils) with late alterations on monocytes. Conversely, Leishmune (R) induced early phenotypic changes in both, neutrophils and monocytes. Moreover, Leishvaccine triggered mixed activation-related phenotypic changes on T-cells (CD4(+) and CD8(+)) and B-lymphocytes, whereas Leishmune (R) promoted a selective response, mainly associated with CD8(+) T-cell activation. Mixed cytokine profile (IFN-gamma/IL-4) was observed in Leishvaccine immunized dogs whereas a selective pro-inflammatory pattern (IFN-gamma/NO) was induced by Leishmune vaccination. The distinct immunological profile triggered by Leishvaccine and Leishmune may be a direct consequence of the distinct biochemical composition of these immunobiological, i.e. complex versus purified Leishmania antigen along with Bacillus Calmette-Guerin (BCG) versus saponin adjuvant. Both immunobiologicals are able to activate phagocytes and CD8(+) T-cells and therefore could be considered as a putative vaccines against canine visceral leishmaniasis (OIL). (C) 2011 Elsevier B.V. All rights reserved.