Neuroimmunomodulation in the intestinal mucosa.
The intestine contains major subdivisions of the nervous and immune systems. The lymphoid compartments of the intestine contain functionally distinguishable populations of immunologic cells and are innervated differently. The lamina propria has an extensive network of nerves using the neuropeptides SOM, SP, and VIP. Subpopulations of T cells, B cells, cells of the monocyte/macrophage line, and several other immunologically relevant cells have the ability to recognize and respond to these neuropeptide signals. SOM, SP, and VIP can act as potent regulators of lymphoid cell proliferation and interleukin and immunoglobulin production. The unusual effector lymphocytes in the epithelial layer of the intestine can be exposed to SP and VIP, and their responses may be regulated by these peptides. In the organized lymphoid compartments such as Peyer's patches, the neuropeptides VIP and SP may regulate the accumulation or recirculation of affector lymphocytes from the central compartment of the immune system and their subsequent response to antigens. The large array of immunoregulatory effects that have been found with these neuropeptides suggest that local neurophysiologic signals in the intestinal lymphoid microenvironments can regulate selected aspects of immune responses. The intestine is likely to be a highly specialized venue for neuroimmunomodulation in intact animals, and this has important implications in the physiologic and pathologic responses of the gut. Further investigations of these regulatory pathways will lead to new concepts concerning neural-immune interactions in general and the regulation of mucosal immunology in particular.
Ottaway
C A
CA
Department of Medicine, University of Toronto, Ontario, Canada.
D000818:Animals; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology*; D007422:Intestines / Q000294:innervation; D008214:Lymphocytes / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D015213:Neuroimmunomodulation / Q000502:physiology*; D013004:Somatostatin / Q000502:physiology*; D013373:Substance P / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000276:immunology*
D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin