title: Antiproliferative and immunosuppressive properties of microcolin A, a marine-derived lipopeptide.
abstract: The immunosuppressive effects of microcolin A, a lipopeptide extracted from the marine blue green alga Lyngbya majuscula were investigated. Microcolin A suppressed concanavalin A (IC50 = 5.8 nM), phytohemagglutinin (IC50 = 12.5 nM) and lipopolysaccharide (IC50 = 8.0 nM) induced proliferation of murine splenocytes. Mixed lymphocyte reaction (IC50 = 5.0 nM), anti-IgM (mu-chain specific) (IC50 = 10.0 nM), and phorbol 12-myristate 13-acetate plus ionomycin (IC50 = 5.8 nM) stimulation of murine splenocytes were all similarly suppressed by microcolin A. The inhibitory activity of microcolin A was time-dependent and reversible and was not associated with a reduction in cell viability. Moreover, microcolin A not only inhibited IL-2 production and IL-2 receptor expression by concanavalin A activated splenocytes, but also suppressed in vitro antibody responsiveness to keyhole limpet hemocyanin. These results indicate that microcolin A is a potent immunosuppressive and antiproliferative agent.
authors.affiliation: Division of Biomedical Marine Research, Harbor Branch Oceanographic Institution, Fort Pierce, FL 34946, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Zhang
authors.forename: R E
authors.initials: RE
authors.lastname: Longley
authors.forename: F E
authors.initials: FE
authors.lastname: Koehn
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D007075:Immunoglobulin M; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects*; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology
chemical_list: D007075:Immunoglobulin M; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D008934:Mitogens; D009842:Oligopeptides; D011759:Pyrrolidines; D015375:Receptors, Interleukin-2; C076335:microcolin A; D016572:Cyclosporine