Biased T cell receptor V alpha region repertoire in the synovial fluid of rheumatoid arthritis patients.

Synovial T lymphocytes seem to contribute to the pathogenesis of rheumatoid arthritis (RA). Since very little is known about the structural heterogeneity of their T cell antigen receptors (TcR), we analyzed TcR alpha chain mRNA of synovial fluid T cells from two RA patients. TcR alpha chain cDNA was amplified by the polymerase chain reaction with single-sided specificity for the alpha chain constant (C alpha) gene segment, and the nucleotide sequences of 51 functionally rearranged cDNA clones were determined. Twenty different V alpha genes and 26 different J alpha gene segments were utilized in these cDNA clones. Three of the V alpha gene segments which are frequently (8%-17% total) expressed in synovial fluid T cells have rarely been found in the TcR repertoire of peripheral blood T cells from healthy individuals. The T cell responses in the rheumatic synovia analyzed here are not oligoclonal, but the usage of TcR V alpha genes is biased.