title: Characterization of a cyclosporin A-sensitive activation pathway in cultured T and natural killer cells.
abstract: Previously, the authors have described a molecule, identified by the LD6 monoclonal antibody (MoAb), present at the cell surface of long-term cultured T and Natural Killer (NK) cells which is involved in cell triggering. In the study described here the authors used biotin surface labelling and immunoprecipitation to show that LD6 MoAb recognizes a surface protein of approximately 65 kDa. In combination with submitogenic concentrations of phorbol esters (PMA); LD6 MoAb was able to induce accumulation of mRNA specific for GM-CSF, gamma-IFN and TNF-alpha and release of these cytokines by LD6+ T-cell lines. Both lymphokine production and lymphokine-specific mRNA accumulation induced by the LD6 MoAb were blocked totally by Cyclosporin A (CsA). To investigate the mechanism(s) of signal transduction through this activatory pathway, the authors performed Ca++ mobilization experiments. The results of these experiments suggested a role for Ca++ in signal transduction. The Ca++ mobilization induced by LD6 MoAb cross-linking could be inhibited totally by the use of pertussis toxin, indicating a possible role for G proteins in signalling through the LD6 MoAb-reactive molecule. Western blot analysis performed with an anti-phosphotyrosine antibody did not suggest that tyrosine kinase activation has a role.
authors.affiliation: Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cantoni
authors.forename: A
authors.initials: A
authors.lastname: Cambiaggi
authors.forename: S
authors.initials: S
authors.lastname: Sforzini
authors.forename: A
authors.initials: A
authors.lastname: Poggi
authors.forename: M
authors.initials: M
authors.lastname: Viale
authors.forename: R
authors.initials: R
authors.lastname: Biassoni
authors.forename: S
authors.initials: S
authors.lastname: Ferrini
mesh_terms: D000911:Antibodies, Monoclonal; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D016572:Cyclosporine / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis; D004351:Drug Resistance; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects*; D037342:Pertussis Toxin; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D016207:Cytokines; D012333:RNA, Messenger; D010566:Virulence Factors, Bordetella; D016572:Cyclosporine; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium