Testicular macrophages: development and function in health and disease

Macrophages comprise a heterogeneous immune cell population and display niche-specific phenotypes and functions in almost all organs. Testicular macrophages (TMs) perform essential immune and non-immune functions in the mammalian male gonads. Here, we discuss the most recent findings on TM ontogeny, heterogeneity, and function under steady state and inflammatory conditions. We also highlight new discoveries regarding the functions of macrophages during bacterial and viral infections of the testes and how macrophages may indirectly help the establishment of a reservoir through virus seeding. Understanding TM function and macrophage-related mechanisms of disease might assist in developing new opportunities for intervention in male infertility.