title: BTS 71 412: in vitro profile of a novel pyrazolinone immunosuppressant.
abstract: The effect of BTS 71 412, 4-acetyl-1-(4-chlorophenyl)-3-(2-methylthiophenyl)- 3-pyrazolin-5-one, has been determined on a variety of immune reactions in vitro in order to gain a further insight into the mechanisms whereby this novel immunosuppressive drug suppresses cell and antibody mediated immune responses in vivo. BTS 71 412 markedly inhibited [3H]thymidine incorporation by mouse splenocytes activated with concanavalin-A (IC50 = 20.1 microM), phytohaemagglutinin (IC50 = 4.6 microM), lipopolysaccharide (LPS) (IC50 = 3.2 microM), anti-IgM (mu-chain specific) (IC50 = 2.6 microM), or mixed lymphocyte culture (IC50 = 8.4 microM). Activity of BTS 71 412 was not associated with a reduction in cell viability. BTS 71 412 also prevented [3H]thymidine incorporation by the murine HT-2 helper T-cell clone when cultured with IL-2 (IC50 = 7.6 microM) or IL-4 (IC50 = 7.3 microM), enriched Thy-1+ T-lymphocytes stimulated with phorbol 12-myristate 13-acetate plus ionomycin (IC50 = 3.6 microM), and enriched B220- B-lymphocytes stimulated with LPS (IC50 = 3.0 microM). Splenocytes cultured with BTS 71 412 produced lower levels of interleukin (IL)-2, IL-10 and interferon-gamma when stimulated with concanavalin-A (IC50 values 42 microM, 22 microM and 60 microM, respectively). The compound suppressed in vitro antibody responses to keyhole limpet haemocyanin (IC50 = 2.3 microM), but did not reproducibly inhibit IL-6 or tumour necrosis factor alpha production by adherent peritoneal macrophages stimulated with LPS in vitro. These data indicate that BTS 71 412 specifically inhibits both B- and T-lymphocyte activation and proliferation but does not affect macrophage activation in vitro.
authors.affiliation: Boots Pharmaceuticals Research Department, Nottingham, U.K.
authors.forename: P T
authors.initials: PT
authors.lastname: Tomkins
authors.forename: K L
authors.initials: KL
authors.lastname: Cooper
authors.forename: S A
authors.initials: SA
authors.lastname: Titchmarsh
authors.forename: P
authors.initials: P
authors.lastname: Appleby
authors.forename: D G
authors.initials: DG
authors.lastname: Webber
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000941:Antigens / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006433:Hemocyanins / Q000276:immunology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011720:Pyrazoles / Q000737:chemistry / Q000494:pharmacology*; D047069:Pyrazolones; D013154:Spleen / Q000276:immunology / Q000378:metabolism
chemical_list: D000941:Antigens; C096210:BTS 71 412; D016207:Cytokines; D007166:Immunosuppressive Agents; D011720:Pyrazoles; D047069:Pyrazolones; D003907:Dexamethasone; D016572:Cyclosporine; D006433:Hemocyanins; D003513:Cycloheximide; C032808:keyhole-limpet hemocyanin