Human Gut-Associated Natural Killer Cells in Health and Disease

Human Gut-Associated Natural Killer Cells in Health and Disease Alessandro Poggi1*, Roberto Benelli2, Roberta Venè1, Delfina Costa1, Nicoletta Ferrari1, Francesca Tosetti1 and Maria Raffaella Zocchi3 1Molecular Oncology and Angiogenesis Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy 2Immunology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy 3Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy It is well established that natural killer (NK) cells are involved in both innate and adaptive immunity. Indeed, they can recognize molecules induced at the cell surface by stress signals and virus infections. The functions of NK cells in the gut are much more complex. Gut NK cells are not precisely organized in lymphoid aggregates but rather scattered in the epithelium or in the stroma, where they come in contact with a multitude of antigens derived from commensal or pathogenic microorganisms in addition to components of microbiota. Furthermore, NK cells in the bowel interact with several cell types, including epithelial cells, fibroblasts, macrophages, dendritic cells, and T lymphocytes, and contribute to the maintenance of immune homeostasis and development of efficient immune responses. NK cells have a key role in the response to intestinal bacterial infections, primarily through production of IFNγ, which can stimulate recruitment of additional NK cells from periphera...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research