Thus, our observations that CD4+ T cells expressing two functional TCR transcripts are significantly enriched in SG tissue compared with PB in pSS (Table 2) and are found in approximately 15% of the clonal expansions (Table 3) are of particular interest

Thus, our observations that CD4+ T cells expressing two functional TCR transcripts are significantly enriched in SG tissue compared with PB in pSS (Table 2) and are found in approximately 15% of the clonal expansions (Table 3) are of particular interest. cells with glandular dysfunction. Knowledge of paired TCR and sequences enables further work toward identification of target antigens and development of novel therapies. Introduction Sj?grens syndrome (SS) is a chronic, debilitating rheumatic autoimmune disease with hallmark features of severe dry mouth, dry eyes, and autoantibodies to systemic nuclear antigens (1, 2). Criteria for disease classification include both subjective symptoms and objective steps of dry eyes and mouth, presence of Ro/SS-A and La/SS-B autoantibodies, and focal lymphocytic infiltration of biopsied minor salivary gland (SG) tissue (3). Presence of at least one cluster of 50 lymphocytes in 4 mm2 of labial SG tissue, defined as a Mouse monoclonal to SKP2 focus, is usually sensitive and specific for SS (3, 4) and occurs in parallel with comparable infiltrates in submandibular and parotid SGs (4). The focal lymphocytic infiltrates are dominated by CD4+ T cells (5C8) expressing T cell receptors (TCRs) (9, 10) with markers of activation (6, 8) and memory (10, 11), though CD8+ T cells are invariably present. B lymphocyte and macrophage populations increase with disease severity (12). T cells expressing TCRs interact with peptide antigen in the context of HLA molecules. The amino acids responsible for peptide antigen binding are located in the third complementarity-determining regions (CDR3s) of the and chains. CDR3 is the most B-Raf IN 1 variable portion of the TCR, as recombination allows for various combinations of variable (V), diversity (D, in the case of the chain), and joining (J) gene segments as well as for the addition of random, nontemplated nucleotides into the joints between gene segments; these are referred to as NDN-region additions in the chain and simply N-region additions in the chain. In development, T cells simultaneously rearrange both TCR loci (13), resulting in a potential for mature cells made up of dual functional TCR gene rearrangements (14). Prior studies evaluated TCR V gene family usage in main SS (pSS) SG tissue by immunostaining (15, 16), single-strand conformational polymorphism analysis (17, 18), or PCR in combination with hybridization techniques (10, 19, 20). TCR sequences derived from bulk tissue and sequenced following cloning into bacterial vectors or phage were polyclonal and exhibited some preferential V gene usage that varied from patient to patient. Some studies evaluating few patients found TCR motifs in CD3+ T cells within individuals suggesting antigen-driven selection (17, 18, 21). However, whether these TCR motifs occurred in expanded clones or CD4+, CD8+, or memory subsets is unknown. There is also little knowledge of the TCR gene usage of T cells from SG tissue of pSS patients, with two B-Raf IN 1 studies evaluating fewer than 20 cells each (22, 23) and a third study evaluating only a portion of the known V gene families (20). Knowledge of paired TCR and B-Raf IN 1 sequences from SG clonal expansions is required for discovering the antigens driving T cell activation and growth in SG tissue. Importantly, the studies referenced above were subject to PCR amplification bias, precluding a precise evaluation of the TCR repertoire in the SG of SS patients. The specificity of SG CD4+ T cells and their role in SS is not understood. Identification of autoantigens can uncover pathologic mechanisms and revolutionize approaches to disease.