An approach to hemoglobin recycling through Leishmania infected macrophage and its impact on visceral leishmaniasis

Leishmania, due to a biosynthetic deficiency characteristically requires exogenous heme for in vitro growth. Through present study, we have investigated the relevance of CD163 and HCP-1 in trafficking of Hb macrophages sensitized with L. donovani.. Over expression of CD163 on macrophage after its stimulation with parasite is crucial to enhance the adhesive forces to optimize Hb binding on parasite to ensure its survival. It was shown that stimulation with Leishmania donovani, macrophage in the presence of hemoglobin, could trigger efficient IL-10 production. This observation is relevant to the pathogenesis which is linked to direct effect of IL-10 on CD163 expression, which make availability of Hb/heme to the intracellular L. donovani which could contribute to the anemic condition in Kala azar infected patients.