Pathological roles of macrophages in Leishmania infections

Macrophages are the major host cells for Leishmania parasites, and determine the fate of infection by either limiting or allowing growth of the parasites, resulting in development or control of leishmaniasis, respectively. They also play important roles in causing pathological outcomes during Leishmania infection. The pathophysi-ology is complex and include a wide variety of molecular and cellular responses including enhancement of in-flammatory responses by releasing cytokines, causing damages to surrounding cells by reactive oxygen species, or disordered phagocytosis of other cells. It is of note that disease severity in leishmaniasis sometimes does not correlate with parasite burdens, indicating that pathological roles of macrophages are not necessarily linked to their parasite-killing activities that are often defined by M1/M2 status. Here, we review the roles of macrophages in leishmaniasis with a focus on their pathological mechanisms in disease development.

Automated summary

Macrophages are crucial in determining the fate of Leishmania infection and can either limit or allow parasite growth, leading to disease development or control. They also contribute to pathological outcomes during infection through various molecular and cellular responses, including inflammatory responses, reactive oxygen species-induced cell damage, and disordered phagocytosis. Importantly, the severity of leishmaniasis does not always correlate with parasite burdens, highlighting that the pathological roles of macrophages are not solely dependent on their ability to kill parasites. In this review, we focus on the roles of macrophages in leishmaniasis and their contribution to disease development.