Next generation vaccines may be delivered via skin and mucosa. The stratified squamous epithelium (SSE) represents the outermost layer of skin (epidermis) and Type II mucosa (epithelium). Langerhans cells (LC) have been considered the sole antigen-presenting cell (APC) to inhabit the SSE, however, we and others have shown that dendritic cells (DC) are also present. Importantly, there are functional differences in how LCs and DCs take up and process pathogens as well as their ability to activate and polarise T cells. A correct definition and functional characterisation of APCs in skin and anogenital tissues is of the utmost importance for the design of better vaccines and blocking pathogen transmission.
Here, we demonstrate our access to a wide range of human tissues that contain an SSE including every anogenital tissue that pathogens may encounter during transmission. We demonstrate our highly optimised protocols to isolate functionally intact DCs from LCs from these tissues and demonstrate how to correctly discriminate these two cells. We then: examine the transcriptions profiles and ontogeny of these cells using RNA seq; determine the relative proportions of these cells across different tissues using flow cytometry; carry out functional antigen presentations assays using FACS sorted cell populations; examine how these cells migrate through tissue using fluorescence microscopy.