title: Predominant TCR-alpha beta variable and joining gene expression by muscle-infiltrating lymphocytes in the idiopathic inflammatory myopathies.
abstract: The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of diseases in which autoreactive T cells are thought to play a pathogenetic role. We have determined the pattern of TCR-alpha beta gene expression by muscle-infiltrating lymphocytes within clinically and serologically defined groups of IIM patients. We utilized the PCR to study TCR V gene expression in muscle biopsies from nine polymyositis (PM) and eight dermatomyositis (DM) patients, all of whom had autoantibodies directed against histidyl-transfer RNA synthetase (anti-Jo-1 autoantibodies). While the TCR repertoire in DM patients was generally polyclonal, an oligoclonal profile characterized PM patients. Certain V gene families were predominantly expressed; V alpha 1 and V beta 6 gene families were detected in 82 and 91% of PM biopsies, respectively. TCR expression was characterized further by analyzing J gene usage from four PM patients expressing the V beta 6 gene. Sequence analysis of 40 independent recombinants (10 per patient) identified only seven V beta 6 clonotypes and restricted usage of the related J beta 2.1, -2.3, and -2.7 genes. These data, describing predominant TCR V and J gene usage by muscle-infiltrating lymphocytes in myositis patients, suggest that Ag-driven T cell responses may play a primary role in mediating some forms of the IIM.
authors.affiliation: Laboratory of Molecular Immunology, Food and Drug Administration, Bethesda, MD 20892.
authors.forename: T P
authors.initials: TP
authors.lastname: O'Hanlon
authors.forename: M C
authors.initials: MC
authors.lastname: Dalakas
authors.forename: P H
authors.initials: PH
authors.lastname: Plotz
authors.forename: F W
authors.initials: FW
authors.lastname: Miller
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001323:Autoantibodies; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009132:Muscles / Q000276:immunology*; D009220:Myositis / Q000235:genetics* / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D017931:DNA Primers; D016693:Receptors, Antigen, T-Cell, alpha-beta