Restricted expression of T cell receptor V_β but not V_α genes in rheumatoid arthritis

Synovial fluids of patients with rheumatoid arthritis contain activated T lymphocytes that may play an important role in the pathogenesis of the disease. Previous studies have suggested that the T cell receptor (TcR) repertoire of these cells is restricted, reflecting in vivo selection of a limited number of T cell specificities at the site of inflammation. To characterize better these T cell populations we used the polymerase chain reaction technology to estimate the proportion of TcR alpha and beta RNA containing any particular V elements from transcripts directly isolated from the synovial fluid cells and from peripheral blood mononuclear cells of three patients with rheumatoid arthritis. Our data show that, in contrast to peripheral blood mononuclear cells, synovial fluid T cells expressed only few V beta transcripts, one of which was overrepresented in two patients. Peripheral and joint fluid T cells, on the other hand, appeared to express the same set of non-restricted V alpha elements. These results suggest that a major antigen associated with the pathogenesis of rheumatoid arthritis may interact selectively with the V beta component of the TcR.