Generation of interleukin-2-dependent T cell lines from synovial fluids in rheumatoid arthritis.

Synovial fluids from rheumatoid arthritis (RA) patients were found to contain activated T lymphocytes that could be maintained as continuous T cell lines (CTCL) in the presence of the T cell growth factor, interleukin (IL)-2. The CTCL predominantly expressed the OKT8 phenotype and were Ia antigen positive. IL-2-dependent RA CTCL could be maintained in an active dividing state by the presence of RA synovial fluids, whereas IL-2-dependent CTCL from mitogen stimulated PBL failed to respond to the fluids, which were shown to contain IL-2. This suggested that RA CTCL exhibit unique properties not possessed by normal PBL CTCL. The CTCL generated from activated synovial T lymphocyte populations in RA may be used to assess the functions of these cells and their responses to regulatory factors.