Adaptations of intestinal macrophages to an antigen-rich environment.
Intestinal macrophages, preferentially located in the subepithelial lamina propria, represent in humans the largest pool of tissue macrophages. To comply with their main task, i.e. the efficient removal of microbes and particulate matter that might have gained access to the mucosa from the intestinal lumen while maintaining local tissue homeostasis, several phenotypic and functional adaptations evolved. Most notably, microbe-associated molecular pattern (MAMP) receptors, including the lipopolysaccharide receptors CD14 and TLR4, but also the Fc receptors for IgA and IgG are absent on most intestinal Mø. Here we review recent findings on the phenotypic and functional adaptations of intestinal Mø and their implications for the pathogenesis of inflammatory bowel diseases.
Schenk
Mirjam
M
Institute of Pathology, University of Bern, Murtenstrasse 31, CH-3010 Bern, Switzerland.
Mueller
Christoph
C
D000222:Adaptation, Physiological; D000818:Animals; D001419:Bacteria / Q000276:immunology*; D018407:Bacterial Physiological Phenomena; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000276:immunology / Q000382:microbiology / Q000503:physiopathology*; D007413:Intestinal Mucosa / Q000276:immunology* / Q000382:microbiology / Q000502:physiology*; D007422:Intestines / Q000276:immunology / Q000382:microbiology; D018950:Lipopolysaccharide Receptors / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism* / Q000382:microbiology; D052638:Particulate Matter / Q000276:immunology; D011961:Receptors, Fc / Q000276:immunology / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000378:metabolism
D018950:Lipopolysaccharide Receptors; D052638:Particulate Matter; D011961:Receptors, Fc; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4