title: Effect of cyclosporin A on T cell clones from severe aplastic anemia: differential sensitivity of TNF and GM-CSF production.
abstract: In this study we have analyzed the activity of Cyclosporin A (CsA) on the "in vitro" production of TNF and IL-3/GM-CSF as a preliminary basis for explaining the successful use of CsA in aplastic patients. Thus, 73 T cell clones, obtained by a limiting dilution technique from the peripheral blood and bone marrow of 3 patients with severe aplastic anemia (SAA), were studied for TNF and IL-3/GM-CSF production as induced by stimulation with 1% PHA plus 1 ng/ml TPA. Lymphokines obtained in this manner were then tested by biological assays. Twelve out of the initial 73 T cell clones were selected for the production of a large quantity of IL-3/GM-CSF and/or TNF. With these clones we studied the ability of CsA to inhibit TNF and IL-3/GM-CSF production, which was stimulated with specific monoclonal antibodies directed against the CD2 and CD3 surface antigens. TNF and IL-3/GM-CSF production displayed a different sensitivity to CsA inhibition. In fact, at 400 ng/ml CsA a residual production of IL-3/GM-CSF was present in all clones tested (CD3: 21.8% and CD2: 14.4% of the maximal IL-3/GM-CSF activity), while secretion of TNF was virtually abrogated at 100 ng/ml. Moreover, the mean ID50 for TNF production was significantly lower than that of IL-3/GM-CSF (CD2: p = 0.028, CD3: p = 0.01). Using specific anti-IL-3 and anti-GM-CSF monoclonal antibodies, we showed that only GM-CSF, and not IL-3, was resistant to CsA inhibition. In conclusion, these results may represent a possible explanation of the successful use of CsA in the treatment of some patients with SAA.
authors.affiliation: Laboratorio di Farmacologia Tossicologica, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Viale
authors.forename: A
authors.initials: A
authors.lastname: Bacigalupo
authors.forename: S
authors.initials: S
authors.lastname: Ferrini
authors.forename: A
authors.initials: A
authors.lastname: Nicolin
mesh_terms: D000741:Anemia, Aplastic / Q000473:pathology*; D002999:Clone Cells / Q000187:drug effects; D016572:Cyclosporine / Q000494:pharmacology*; D003864:Depression, Chemical; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis*; D006801:Humans; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D016572:Cyclosporine