Androgens and immune cell function.

Androgens can modulate immune cell function and may contribute to differences in the prevalence and severity of common inflammatory conditions. Although most immune cells are androgen targets, our understanding of how changes in androgen bioavailability can affect immune responses is incomplete. Androgens alter immune cell composition, phenotype and activation by modulating expression and secretion of inflammatory mediators or by altering development and maturation of immune cell precursors. Androgens are generally associated with having suppressive effects on the immune system but their impacts are cell and tissue context dependent and can be highly nuanced even within immune cell subsets. In response to androgens, innate immune cells such as neutrophils, monocytes, and macrophages increase production of the anti-inflammatory cytokine IL10 and decrease nitric oxide production. Androgens promote differentiation of T cell subsets and reduce production of inflammatory mediators, such as IFNG, IL4 and IL5. Additionally, androgens/AR can promote maturation of B cells. Thus, androgens can be considered as immunomodulatory agents but further work is required to understand the precise molecular pathways that are regulated at the intersection between endocrine and inflammatory signals. This narrative review focusses on summarising our current understanding of how androgens can alter immune cell function and how this might affect inflammatory responses in health and disease.