Advantages and limitations of using Caco-2 cells for in vitro M cell model

Oral vaccine development is reliant upon specific targeting of antigens to the gut associated lymphoid tissue (GALT). GALT is comprised of isolated and aggregated lymphoid follicles. Follicle associated epithelia (FAE) contains both enterocytes and specialized M cells, which perform the key role of luminal sampling and transport of antigens to lymphoid tissues cells beneath (FAE), initiating the mucosal immune response. The antigen-sampling M-cells are exploited by a number of pathogens including Salmonella (Autenrieth et al., 1996) or Yersinia (Jones et al., 1994). Pathogen receptors expressed by M cells have potential as target for the delivery of vaccine antigens. In this study we used the human colon adenocarcinoma cell line, Caco-2 cells, co-cultured with Raji B cells to stimulate differentiation of M cell like cells, in order to model this interface in vitro. Transwell based Caco-2/Raji B cell culture model (Gullberg, 2000, Mack et al. 2009) allow for the study of M cells in vitro and can play a crucial role in the development of targeted oral vaccines (Tyrer, 2007). However Caco-2 cells are polyclonal nature and this high diversity has resulted in the need for standardised protocols (concernin