T-CELL ANTIGEN RECEPTOR V-GENE USAGE - INCREASES IN V-BETA-8+ T-CELLS IN CROHNS-DISEASE

Crohn's disease represents part of a spectrum of inflammatory bowel diseases characterized by immune regulatory defects and genetic predisposition. T cell antigen receptor V gene usage by T lymphocytes was investigated using four MAbs specific for various V gene products. One MAb (Ti3a), reactive with Vβ8 gene products, detected increased numbers of T cells in a subset of Crohn's disease patients as compared with normal controls and ulcerative colitis patients. In family studies there was no apparent inherited predisposition to the use of Vβ8 genes, and there was no association between a restriction fragment length polymorphism of the Vβ8.1 gene and Crohn's disease. The Vβ8+ T cells were concentrated in the mesenteric lymph nodes draining the inflammatory lesions and belonged to both the CD4+ and CD8+ T cell subsets. In contrast, lamina propria and intraepithelial T cells were not enriched in Vβ8+ T cells, suggesting that these cells were participating in the afferent limb of a gut-associated immune response. The expanded Vβ8+ T cells in Crohn's disease appear to result from an immune response to an as yet unknown antigen.