The Role of Lympho-Epithelial Interactions in the Regulation of Small Intestinal Epithelium Proliferation

Abstract

There is evidence that immune system participates in the regulation of intestinal epithelial proliferation and differentiation. It has been proposed¹ that activated T lymphocytes affect crypt cell turnover through release of soluble products, i. e., lymphokines. This point of view has more recently received additional experimental confirmation. It was shown² that Con-A-stimulated intraepithelial lymphocytes and spleen cells suppress growth and modulate la expression by intestinal epithelial cell line. The stimulation of T lymphocytes with pokeweed mitogen or anti-CD3 monoclonal antibodies applied to intestinal organ culture enhanced the rate of crypt cell proliferation.³ Lymphocyte culture supernatants modulate [³H]-thymidine ([³H]TdR) incorporation into isolated small intestinal crypt cells.⁴ There are also data suggesting that lymphocytes induce formation of M cells⁵ and regulate Goblet cell development.⁶ The involvment of immune factors in regulation of intestinal epithelium functions is supported by data on Interleukin-6 receptor expression in intestinal epithelial cells.⁷