Conserved Motifs in Rheumatoid Arthritis Synovial Tissue T-Cell Receptor β Chains

Abstract

Rheumatoid arthritis is genetically linked to major histocompatibility complex (MHC) molecules (HLA-DR4 and related molecules) and characterized pathologically by high levels of HLA-DR expression and infiltration of proliferative of synovial tissue with CD4+ T lymphocytes. T-lymphocyte activation is driven by specific signaling through polymorphic alpha/beta T-cell receptors (TCRs) that are reactive with antigen-MHC complexes present at the sites of inflammation. We are interested in characterizing rheumatoid TCRs molecularly to ascertain potential binding surfaces for antigen+MHC in synovial tissue. Accordingly, we have recently investigated the TCR alpha and beta chain heterogeneity in a series of 10 rheumatoid synovia obtained at the time of joint surgery. The most frequently detected V beta families were V beta 12, 14, and 17, each of which was found in 80% of specimens. We report here the molecular cloning and sequence analysis of 20 cloned V beta segments amplified with a V beta 14 family-specific TCR primer, and six cloned V beta segments amplified with a V beta 17 family-specific TCR primer from four rheumatoid synovia. Comparison with the data base revealed that these sequences belonged to the closely related V beta 3, V beta 14, and V beta 17 families. Dominant clones were apparent in two of the individuals by the presence of identical V-D-J regions, suggesting an antigen-driven process. Amino acid sequence analysis revealed a conserved motif in the putative fourth hypervariable region or CDR4. Molecular modeling of this epitope suggests that charged side chains are available for binding to ligand structures (e.g., antigen, MHC, or superantigen). We suggest this epitope may play a role in the molecular pathogenesis of rheumatoid arthritis.

Detection of T Cell Receptors in Early Rheumatoid Arthritis Synovial Tissue

“…The sequences shown in figure 4 were closely related to some V(D)J sequences previously described by us in patients with chronic RA [ 16,20]. For the P-chains, JP2.3 use was seen in both biopsies, and this has previously been implicated in chronic RA.…”

“…The sequences are shown in fig ure 4. As we have previously noted, th e V(317 primer used in our studies has homology to V(33 and V(314 [20]. When used in the PCR program employed in these studies, the different members of the V(33/14/17 'superfamily' of TCRs all may be amplified by this primer.…”

“…This was performed as previously described [16,20]. Briefly, PCR products were gel purified and cloned into TA vector (InVitro-…”

“…Calif., USA). Sequencing of clones utilized printers from the vector [ 16,20], with double-stranded sequencing employing Taq polymerase as previously described [21], Both strands were sequenced to assure the fidelity of the sequence information. Se quence analysis with J region assignments was pefornted as previous ly described [16.20].…”

Synovial T Cell Receptor Heterogeneity in Early Arthritis

“…The specificity of this clone has been further mapped to amino acids 251-265 of the 65-kD HSP. In addition to these pairings, there was a larger group which included several sequences within the related TCR Vß3, Vß14 and Vß17 families, which are known to be related in sequence [38,39]. In this grouping of 8 sequences, 3 were Vß14, 1 was Vß3, and 2 were Vß17, with the remainder Vß6 or Vß8.…”