USING an ELISA technique, concentrations of gamma-interferon and interleukin-2 were assayed in the supernatants of colonic intraepithelial lymphocytes cultured with or without phytohaemagglutinin (PHA). Intraepithelial lymphocytes produced low concentrations of gamma-interferon and interleukin-2 when stimulated with PHA, but significantly more than when unstimulated (p < 0.05). There was no difference in production of these cytokines by IEL from control or inflammatory bowel disease.
Hoang, P., Dalton, HR., Desilv, HJ., & Jewell, DP. (1994). Cytokine Production By Human Colonic Intraepithelial Lymphocytes in Controls and Ulcerative-colitis. Mediators of Inflammation, 3(3), 219-222. https://doi.org/10.1155/S0962935194000311 (Original work published 1994)