Use of fluorescence imaging to investigate the structure and function of intestinal M cells.

Fluorescence imaging technology can be applied to many aspects of cell biology ranging from the analysis of specific markers in cells and tissues to the biological actions and distribution of fluorescent proteins or particles in living cells. In this review, we examine the role of fluorescence imaging, in conjunction with other microscopical techniques, to study sites of uptake of material across the gastrointestinal epithelium. We will focus primarily on intestinal M cells, specialised antigen-sampling cells in the epithelium of the gut-associated lymphoid tissue (GALT), including Peyer's patches. In addition to their importance as sites for uptake of inert material, and hence their potential as a route of delivery of vaccines, etc., M cells are also a major site of infection by a range of microbial pathogens. The application of new fluorescence imaging technologies has expanded our knowledge on the structure, development and function of these fascinating cells.