INDIVIDUALS FROM MULTIPLEX INSULIN-DEPENDENT DIABETES-MELLITUS (IDDM)FAMILIES EXPRESS HIGHER LEVELS OF TCRBV2S1 THAN CONTROLS

T lymphocytes recognise peptide antigens through the T cell antigen re ceptor, which is composed of variable alpha and beta chains, There are forty-six functional variable regions on the beta chain. In this stud y the expression of the T cell receptor beta-chain variable regions 2S 1 and 3S1, in a large cohort of multiplex insulin-dependent diabetes m ellitus families, have been determined by use of monoclonal antibodies and flow cytometry. Peripheral blood was collected from these multipl ex families and three control groups, healthy individuals, sporadic in sulin-dependent diabetes mellitus patients and non-insulin-dependent d iabetes mellitus patients. The level of TCRBV2S1 expression in the mul tiplex families was significantly higher than all the control groups f or both the CD4(+) and CD8(+) T lymphocyte subsets. Detailed analysis of the family data showed that this increased expression was nor assoc iated with age, sex, HLA type or the diabetic phenotype. The TCRBV3S1 expression in all the diabetic cohorts was significantly lower than th e healthy controls, in the CD4 subset only. Derailed analysis of the f amily data showed only the fathers TCRBV3S1 expression was lower than the healthy controls. This study gives further insight into TCRBV usag e which could reflect the mechanism of the autoimmune response in IDDM multiplex families. (C) American Society for Histocompatibility and I mmunogenetics, 1998. Published by Elsevier Science Inc.