Dominant and Shared T Cell Receptor β Chain Variable Regions of T Cells Inducing Synovial Hyperplasia in Rheumatoid Arthritis

Previously, we demonstrated the presence of at least two distinct subpopulations of patients with rheumatoid arthritis (RA) employing a cell-transfer experiment using severe combined immunodeficient (SCID) mice. One group of patients, whose T cells derived from the rheumatoid joints, induced synovial hyperplasia (SB) in the SCID mice (the positive group) The other group did not display the induction of SH (the negative group). TCR/V beta gene usage-analysis indicated that some dominant T cell subpopulations were oligoclonally expanding only in the rheumatoid joints, and not in the periphery of the patients of the positive group. Moreover, these T cell subpopulations were not seen in the joints of patients in the negative group or in non-RA patients. In addition, the preferential uses of certain TCR/V beta s (V beta 8, V beta 12, V beta 13, and V beta 14) genes were demonstrated in these T cells. In this study, to investigate whether these T cells are driven by a certain antigen(s), the third complementarity determining regions (CDR3s) of TCR/V beta, especially V beta 8 and V beta 14 PCR products, were cloned and sequenced. As a result, a dominant CDR3 sequence, CASS-PRERAT-YEQ, was found in V beta 14+ T cells from the rheumatoid joint of a patient (Patient 1) of the positive group with a V beta 14 skew. The identical CDR3 sequence also predominated in V beta 14+ T cells from the rheumatoid joint of another patient (Patient 7) of the positive group with a V beta 14 skew. In addition, in the patients (Patients 4, 7, 8) of the positive group with a V beta 8 skew, other dominant CDR3 sequences, CASS-ENS-YEQ and CASS-LTEP-DTQ, were found as in the case of V beta 14. However, no identical CDR3 sequences were detected dominantly in the joints of the patients in the negative group or in non-RA patients. A V beta 14+ T cell clone (TCL), named G3, with the identical CDR3 sequence, CASS-PRERAT-YEQ, was isolated successfully from Patient 1, and cell transfer of G3 with autologous irradiated peripheral mononuclear cells induced SH in the SCID mice. Taken together, these results suggest that T cells inducing SH, thought to be pathogenic for RA might be driven by a certain shared antigen(s). (C) 1999 Academic Press.