Shifting Macrophage Phenotypes in Leishmaniasis

Abstract

Macrophage phenotypes, such as macrophage (M) 1 (classically activated macrophage) and M2 (alternatively activated macrophage), determine the macrophage role as an effector immune cell or as a permissive host for the intracellular pathogenic protozoan Leishmania spp. Leishmania parasites and the host immune system shape macrophage phenotypes, which in turn can help parasite control or promote infection. Here, we discussed how shifting macrophage phenotypes might change disease outcome in leishmaniasis, by addressing: (1) macrophage phenotypes in leishmaniasis; (2) the functional phenotypes of resident and inflammatory macrophages; (3) the interplay with neutrophils modulates macrophage function; (4) the crosstalk with T cells shapes macrophage phenotypes; and (5) potential therapeutic tools to skew macrophage phenotypes and disease outcomes.