CLONAL EXPANSION OF MYCOBACTERIAL HEAT-SHOCK PROTEIN-REACTIVE T-LYMPHOCYTES IN THE SYNOVIAL-FLUID AND BLOOD OF RHEUMATOID-ARTHRITIS PATIENTS

Objective. To examine the reactivity pattern and T cell receptor (TCR) characteristics of mycobacterial heat-shock protein 65 (hsp65)-reacti ve T cells generated from paired synovial fluid (SF) and peripheral bl ood (PB) samples obtained from rheumatoid arthritis (RA) patients and from healthy subjects. Methods. The reactivity pattern of hsp65-reacti ve T cell clones generated under limiting-dilution conditions was anal yzed in H-3-thymidine incorporation assays, The TCR variable regions o f these hsp65-reactive T cells were characterized by polymerase chain reaction with TCR AV- and BV-specific primers and by DNA sequence anal ysis of the third complementarity-determining region (CDR3). Results. The hsp65-reactive T cells derived both from RA patients and controls preferentially recognized the 1-170 and 303-540 regions of hsp65 and d id not cross-react with human hsp60. The hsp65-reactive T cell clones derived from RA patients displayed a restricted TCR AV and BV gene usa ge, which can be attributed to the limited clonal origin(s) of the ind ependent T cell clones, as evidenced by CDR3 sequence analysis, These clonally expanded T cells were found in both PB and SF and in differen t inflamed joints of RA patients. Conclusion. Our study suggests that there is in vivo clonal activation and expansion of mycobacterial hsp6 5-reactive T cells in patients with RA.