Dominant clones in immortalized T-cell lines from rheumatoid arthritis synovial membranes

Transformation of human T cells by herpesvirus saimiri allows the production of an unlimited number of T cells which express a functional T-cell receptor. In this study we transformed four T-cell lines derived from rheumatoid arthritis synovial membranes. The transformed T cells were mainly CD4+ and expressed the phenotype of activated T cells. They were grown for more than 1 year in the absence of mitogen or feeder cells, and three of them could be maintained without exogenous IL-2. The presence of viral DNA in the transformed cells was shown by in situ hybridization with a probe from the H-DNA region of the virus. No infectious virus could be recovered from the transformed cells. The relative proportion of the 24 different Vbeta families between the four transformed lines showed variations that increased with time. In the two T-cell lines transformed at an early stage of culture, the Vbeta2 family was maintained at about 10%. The dominant Vbeta2 clones that previously have been characterized in the patient were found in all transformed T-cell lines. We have thus shown the feasibility of obtaining transformed T cells from synovial membranes. They contain the dominant clones that are considered of potential importance for the disease, permitting further functional studies.