title: Human T-cell responses to Mycoplasma arthritidis-derived superantigen.
abstract: When injected into mice, Mycoplasma arthritidis causes a chronic arthritis that resembles rheumatoid arthritis, histologically. The organism produces a superantigen termed Mycoplasma arthritidis mitogen or MAM, that in humans preferentially expands T cells whose antigen receptors express V beta 17. T cells with this phenotype appear to be increased in rheumatoid synovial effusions. We describe a novel approach to isolating and characterizing human MAM-reactive T-cell lines and determining their T-cell receptor (TCR) V beta usage. Lines were prepared from T cells that clustered with dendritic cells during a 2-day exposure to MAM. Cluster and noncluster fractions of T cells were then expanded by using feeder cells and a polyclonal mitogen. Most of the MAM reactivity was found in dendritic T-cell clusters, as were most of the T cells expressing TCR V beta 17. After expansion, 76% of the cluster-derived T-cell lines were MAM reactive, while no reactivity was seen in cell lines derived from the noncluster fraction. Of the MAM-reactive lines, 49% expressed V beta 17 on some or all of the cells. Cell lines from both cluster and noncluster fractions were analyzed for TCR V beta mRNA expression by PCR amplification. Other V beta genes (5.1, 7, 8, 12, and 20) were found to be expressed by lines that were MAM reactive, although these were not a major component of the cluster-derived T cells. Some non-cluster-derived lines expressed V beta s 17, 12, and 7, but these proved to be nonreactive to MAM. Therefore, dendritic cells can be used to immunoselect and characterize T cells that express superantigen-reactive TCRs.
authors.affiliation: Rockefeller University, New York, New York.
authors.forename: N
authors.initials: N
authors.lastname: Bhardwaj
authors.forename: A S
authors.initials: AS
authors.lastname: Hodtsev
authors.forename: A
authors.initials: A
authors.lastname: Nisanian
authors.forename: S
authors.initials: S
authors.lastname: Kabak
authors.forename: S M
authors.initials: SM
authors.lastname: Friedman
authors.forename: B C
authors.initials: BC
authors.lastname: Cole
authors.forename: D N
authors.initials: DN
authors.lastname: Posnett
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D000941:Antigens; D000942:Antigens, Bacterial; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D003713:Dendritic Cells / Q000276:immunology; D005434:Flow Cytometry; D015870:Gene Expression; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008934:Mitogens / Q000276:immunology*; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000276:immunology*; D016133:Polymerase Chain Reaction; D011506:Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D018089:Superantigens / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D000942:Antigens, Bacterial; D017931:DNA Primers; D007376:Interleukin-2; D008934:Mitogens; C052996:Mycoplasma arthritidis mitogen; D011506:Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens