Development and characterisation of T lymphocyte lines from human small intestinal biopsies.

T lymphocyte lines were developed from human small intestinal biopsies obtained at the time of gastroduodenoscopy. Lines were established as outgrowths from biopsy specimens in microculture using a combination of T cell mitogens, indomethacin, interleukin (IL-2) and autologous irradiated feeder cells. The predominant phenotype of T cells after six to 12 weeks in culture was CD2, CD3, and CD4 positive. Functionally, these T cell lines secreted IL-2 in response to stimulation with phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) in combination, but not to PHA or PMA alone. Two to 7% of cells in each line expressed natural killer (NK) cell-associated markers--that is, Leu 7, CD16, and Leu 19. Moreover, such cells were cytotoxic for NK sensitive targets, but not for NK resistant targets or allogeneic or autologous Epstein Barr Virus (EBV) transformed B cells. Sufficient numbers of small intestinal lymphoid cells for study were previously available only from patients undergoing surgical resections of the small bowel. The ability to isolate and culture human small intestinal T lymphocytes from gastroscopic intestinal biopsies provides an important new tool for studies of human small intestinal lymphocytes.