Mucosal immunity is the study of the immune system associated with mucosal sites such as the gut mucosa that comprises Peyer’s patches (PPs), intestinal lamina propria, intestinal intraepithelium, cryptopatches, isolated lymphoid follicles in the gut antimesenteric wall, and the mesenteric lymph nodes.
Although mucosal immunity is intended to maintain immunologic homeostasis and health, the host pays a price when inappropriate responses are stimulated by infection. The burst of cytokines, reactive oxygen, or nitrogen species, as well as the release of enzymes or vasoactive mediators, allow the infiltrating immune and inflammatory cells to contribute to disrupted tissue architecture and loss of function. In addition to tissue damage, these responses can cause pathologic amounts of catharsis, pain, or motility disorders, including bronchoconstriction. Further, the oxidative stress induced by chronic inflammation also increases the risk of various cancers.