SELECTION OF T-CELLS REACTIVE AGAINST AUTOLOGOUS B-LYMPHOBLASTOID-CELLS DURING CHRONIC RHEUMATOID-ARTHRITIS

The repertoire and Ag specificity of T cells infiltrating inflamed joi nts from a chronic rheumatoid arthritis (RA) patient were studied in d etail. Repertoire analysis demonstrated a reduced clonality of joint-i nfiltrating lymphocytes (JIL) as compared with patient's PBL, which wa s presumably due to an intra-articular expansion of T cell clones with recurrent TCR features, Strikingly, a large fraction of these JIL T c ell clones, which were predominantly CD8(+), proliferated in vitro whe n exposed to autologous B lymphoblastoid cells (BLC), unlike randomly chosen PBL clones derived from the same patient, This proliferative re sponse was HLA-restricted, which confirmed a classical TCR-mediated re cognition of BLC and was not observed against autologous PHA blasts, s uggesting recognition of either EBV or B cell-specific Ags, Finally, a preliminary analysis of synovial lymphocytes derived from another chr onic RA patient demonstrated a similar enrichment for T cells reactive against autologous BLC within JILs as compared with patient's PBLs, T aken together, these results, which suggest frequent expansions of aut ologous BLC-reactive T cells within inflamed joints of chronic RA pati ents, provide a basis for future studies evaluating the fine specifici ty and pathogenicity of these lymphocytes.