Antigen sampling in the small intestine.
Active sampling of intestinal antigen initiates regulated immune responses that ensure intestinal homeostasis. Several specialized mechanisms transport luminal antigen across the gut epithelium. Epithelium overlying lymphoid compartments is equipped with transcytotic microfold (M) cells that transport particulate material either directly or with the help of dendritic cells (DCs). By contrast, normal villous epithelium transports antigen by means of antigen-shuttling receptors together with phagocytes that scan the gut epithelium and potentially the gut lumen. Here, we examine recent insights into the nature of the epithelial and immune cell types involved in antigen uptake and describe how the process of antigen transport has been visualized by intravital microscopy. These new findings might help optimize antigen delivery systems for mucosal vaccination.
Institute of Immunology, Hannover Medical School, 30625 Hannover, Germany.
Olga
O
Schulz
Oliver
O
Pabst
D000818:Animals; D017951:Antigen Presentation; D000941:Antigens / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D018928:Immunity, Mucosal; D007413:Intestinal Mucosa / Q000276:immunology*; D026901:Membrane Transport Proteins / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology; D057900:Transcytosis / Q000276:immunology
D000941:Antigens; D026901:Membrane Transport Proteins