Increased frequency of abnormal gamma delta T cells in blood of patients with inflammatory bowel diseases

Abstract

We have previously reported a preferential usage of V delta 1/V gamma 8 on TCR-gamma-delta-bearing intraepithelial lymphocytes of the normal human intestine as well as in the inflamed synovial tissue of patients with rheumatoid arthritis. The aim of the present study was to analyze V gene segment usage by gamma delta T cells of the intestine and peripheral blood (PB) from patients with inflammatory bowel disease. Freshly isolated lymphocytes were analyzed by flow cytometry using a panel of V gene subset-specific mAbs. The relative proportion of PB TCR-gamma delta+ cells was increased in patients with Crohn's disease as compared with controls. Interestingly, an increased proportion of PB gamma delta T cells of patients with ulcerative colitis or CrD expressed V delta and V gamma genes typically used by intraepithelial lymphocytes. Thus, increased proportions of V delta 1+ and V gamma 8+ cells were found in the PB of both patient groups. The majority of TCR-gamma delta+ intraepithelial lymphocytes (IEL) in inflamed and noninflamed intestine expressed V delta 1/V gamma 8, and a substantial proportion of V gamma(2,3,4)+ cells were found. These observations suggest a disease-associated appearance of "gut-like" gamma delta T cells in the periphery. Moreover, two patients had a large proportion of gamma delta T cells in their PB of which the majority expressed two distinct V gamma proteins. Both of these patients had a short duration of disease (1 and 10 mo, respectively) and the relative proportion of gamma delta T cells decreased in concert with stabilization of disease. Interestingly, one of the patients had a clonal expansion of a V gamma dual-expressing gamma delta T cell in the PB.