Tγ Cells and Non-Specific Concanavalin A-Induced Suppressor Cell Activity in Vitro in Colonic Inflammatory Bowel Disease and in Colorectal Carcinoma

Recently, Hodgson et al. (1) concluded that nonspecific, mitogen-induced suppressor T cell activity of peripheral blood lymphocytes [PBL] in vitro was decreased in active inflammatory bowel disease [IBD] and suggested that this was important to any concept involving a pathogenetic role for the immune response. In addition, IBD is a risk factor in gastrointestinal malignancies, particularly colorectal carcinoma, and Naor (2) has reviewed the data which led to a hypothesis that suppressor cell activities, both specific and nonspecific, may be significant to the emergence and growth of some malignant tumors. Thus, we quantitated Tγ cells in isolates of PBL and in isolates of lamina proprial lymphocytes [LPL] form patients with IBD, and from patients with colorectal carcinoma, and compared the results with controls including other chronic inflammatory intestinal lesions or benign colonic tumors. Using PBL and LPL, we also assayed Concanavalin A-induced nonspecific suppressor T-cell activity on T-cell responsiveness to Con-A in vitro.