Leishmania infantum LeIF and its recombinant polypeptides induce the maturation of dendritic cells in vitro: an insight for dendritic cells based vaccine

Abstract We previously showed that recombinant Leishmania infantum eukaryotic initiation factor (LieIF) was able to induce the secretion of cytokines IL-12, IL-10 and TNF-α by human monocytes. In this study, we explored in vitro the potential of LieIF to induce phenotypic maturation and functional differentiation of murine bone - marrow derived dendritic cells (BM-DCs). Moreover, in order to identify potential immunnomodulatory regions of LieIF, eight recombinant overlapping protein fragments covering the whole amino acid sequence ofprotein; were constructed and assessed in vitro for their ability to induce maturation of BM-DCs. Our data showed that LieIF and some of its recombinant polypeptides were able to induce elevated expression of CD40, CD80 and CD86 co-stimulatory molecules with concurrent IL-12 production. Moreover, we used an in vivo experimental model of cutaneous leishmaniasis consisted of susceptible Leishmania major - infeced BALB/c mice and we demonstrated that LieIF-pulsed-BM-DCs adoptively transferred in mice were capable to confer protection against a high dose parasite challenge. This study further describes the immunomodulatory properties of LieIF and its polypeptides bringing relevant information for their exploitation as candidate molecules for vaccine development against leishmaniasis.