Dendritic cells and macrophages in the genitourinary tract

Abstract

Dendritic cells (DCs) and macrophages are antigen-presenting cells (APCs) that are important in innate immune defense as well as in the generation and regulation of adaptive immunity against a wide array of pathogens. The genitourinary (GU) tract, which serves an important reproductive function, is constantly exposed to numerous agents of sexually transmitted infections (STIs). To combat these STIs, several subsets of DCs and macrophages are strategically localized within the GU tract. In the female genital mucosa, recruitment and function of these APCs are uniquely governed by sex hormones. This review summarizes the latest advances in our understanding of DCs and macrophages in the GU tract with respect to their subsets, lineage, and function. In addition, we discuss the divergent roles of these cells in immune defense against STIs as well as in maternal tolerance to the fetus.

Figure 1

Heterogeneous populations of vaginal epithelial dendritic cells (DCs). The epithelium of the vagina from 17β-estradiol-treated mice was separated from the lamina propria. Frozen sections of the epithelium were stained with Abs against major histocompatibility complex (MHC) class II (green) and F4/80 (red). Nuclei were labeled with DAPI (blue). Images were captured using an original magnification ×10 (a) or ×40 objective lens (b–d). DAPI, 4’,6-diamidino-2-phenylindole.