Response of synovial fluid T cell clones to Yersinia enterocolitica antigens in patients with reactive Yersinia arthritis.

From synovial fluids of two patients with reactive arthritis following Yersinia enterocolitica infection, T lymphocyte clones were obtained that showed proliferative responses to Y. enterocolitica. The responses required autologous T-cell-depleted peripheral blood mononuclear cells as antigen presenting cells. Three clones were studied in detail; two of them showed a marked and specific response to Yersinia antigens alone, the other one recognized both Yersinia and Salmonella typhimurium antigens. The antigen-specific proliferation of the clones could be completely blocked by monoclonal antibodies to HLA-DR. These experiments show that synovial T lymphocytes presumably involved in the in situ immune response to microbial antigens triggering reactive arthritis can be cloned directly from the site of inflammation.