Peroxisome Proliferator-Activated Receptor-γ-Mediated Polarization of Macrophages inLeishmaniaInfection

Infection is the outcome of a contest between a pathogen and its host. In the disease leishmaniasis, the causative protozoan parasites are harbored inside the macrophages. Leishmania species adapt strategies to make the infection chronic, keeping a balance between their own and the host's defense so as to establish an environment that is favorable for survival and propagation. Activation of peroxisome proliferator-activated receptor (PPAR) is one of the tactics used. This ligand-activated nuclear factor curbs inflammation to protect the host from excessive injuries by setting a limit to its destructive force. In this paper, we report the interaction of host PPARs and the pathogen for visceral leishmaniasis, Leishmania donovani , in vivo and in vitro . PPAR expression is induced by parasitic infection. Leishmanial activation of PPAR γ promotes survival, whereas blockade of PPAR γ facilitates removal of the parasite. Thus, Leishmania parasites harness PPAR γ to increase infectivity.