Detection of T Cell Receptors in Early Rheumatoid Arthritis Synovial Tissue

Abstract

Synovial tissue is rarely available from patients with early synovitis, with the exception of synovial biopsies. However, T cell populations early in the development of synovitis may be enriched in antigen-specific cells and critical to disease pathogenesis. To investigate the T cell repertoire in early synovitis, we utilized a PCR protocol for detection of T cell receptor (TCR) transcripts present in small amounts of synovial tissue. To expand the substrate for PCR, preamplification of cDNA was performed with a 3’ constant region primer plus either a mixture of variable region primers or random hexanucleotides. Utilizing this method improved the sensitivity of detection. This technique is applied here to the analysis of TCR transcripts in synovial biopsies from individuals with early rheumatoid arthritis (RA) and non-RA synovitis. TCR α-chain transcripts were detectable in 5/5 RA and 4/4 non-RA specimens evaluated, with β-chain transcripts detected in 4/5 early RA and 4/4 non-RA specimens evaluated. Confirmation of transcripts by sequencing of cloned PCR products verfied the specificity of amplification. The most frequently expressed TCR V region families in early RA synovitis were Vαl 1, Vαl4, Vα28, Vβ7, Vβ9 and Vβl7. Several of these V regions have previously been implicated in studies of chronic RA synovitis. Jα and Jβ region usage was similar to that seen in chronic RA, and conserved N region motifs were apparent. We conclude that it is possible to detect TCR transcripts in small synovial biopsies from individuals with early arthritis. This technique can be applied to studies of synovitis where limited quantities of synovial tissue are available.

Characterization of Autoreactive T Cells to the Autoantigens Heterogeneous Nuclear Ribonucleoprotein A2 (RA33) and Filaggrin in Patients with Rheumatoid Arthritis

“…R heumatoid arthritis (RA) 4 is a chronic inflammatory joint disease of unknown etiology characterized by hyperplasia of the synovial membrane, degradation of cartilage, and bone erosion. Overexpression of proinflammatory cytokines such as IL-1 and TNF-␣ is considered to drive the destructive processes, but the causes for this disregulated cytokine production are unknown.…”

“…Already in early disease stages the inflamed rheumatoid synovial membrane is characterized by massive infiltration of T cells and other immune cells including B cells, macrophages, and mast cells (3)(4)(5). The majority of synovial T cells are CD4 ϩ memory cells that typically express activation markers such as HLA-DR, CD69, or CD40L but, remarkably, may be deficient in CD28 expression (6).…”

T-cell signal transduction and the role of protein kinase C

“…Furthermore, activated synovial T cells from patients with rheumatoid arthritis can induce the production of cartilage-degrading enzymes such as collagenase from dermal fibroblasts via mechanisms involving direct cell-cell contact [10]. However, the idea that the disease is driven by a particular subpopulation of T cells with restricted expression of TCR variable i gene segments which are localized to the inflamed synovium is still subject to debate [11,12]. The lines of evidence which support T-cell involvement in the aetiology of multiple sclerosis and psoriasis are similar, i.e.…”