Spontaneous secretion of interferon [GAMMA] and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes

• Published in: Gut 1998-05, Vol.42 (5), p.643
• Main Authors: Carol, M, Lambrechts, A, Van Gossum, A, Libin, M, Goldman, M, Mascart-Lemone, F
• Format: Article
• Language: English
• Subjects: Antigens; Biopsy; Colon; Cytokines; Gastrointestinal diseases; Immune system; Lymphocytes; Pathogenesis; Physiology; Proteins; Small intestine
• ISSN: 0017-5749; 1468-3288
• DOI: 10.1136/gut.42.5.643

Background -Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. Aims -To quantify interferon [GAMMA] (IFN-[GAMMA]) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. Patients -Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. Methods -Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-[GAMMA] and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). Results -The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-[GAMMA] (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-[GAMMA] SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-[GAMMA] and IL-4 were mainly produced by CD4 + cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-[GAMMA] in the basal state, and 0.1% secreted IL-4. Conclusions -Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-[GAMMA] and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.