title: Studies on thermophile products. VIII. Isolation of Bacillus stearothermophilus UBT8038, a component that inhibits antigen presentation on mouse macrophages.
abstract: We have found a new compound from thermophile extracts which inhibits antigen presentation on mouse macrophages. The substance inhibits the expression of the class II major histocompatibility molecule (Ia). It was extracted from Bacillus stearothermophilus UBT8038 and purified by silica gel column chromatography. The isolated inhibitor, Fr. 8-A, was a phosphatidylethanolamine with isofatty acids and chemically different from any of the natural or synthetic products which have been reported to modify Ia expression. Fraction 8-A inhibits Ia expression by mouse peritoneal macrophages induced by the supernatant from concanavalin A stimulated spleen cell cultures in a dose-dependent fashion over the range 0.1-10 micrograms/ml. This fraction also exhibited inhibitory effects on antigen presentation by splenic macrophages in vitro and on the mixed leukocyte reaction. The present results show that Fr. 8-A has a unique inhibitory effect on antigen presenting cells.
authors.affiliation: Faculty of Pharmaceutical Sciences, Osaka University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kohama
authors.forename: M
authors.initials: M
authors.lastname: Itoh
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Senba
authors.forename: S
authors.initials: S
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Mimura
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects*; D001411:Geobacillus stearothermophilus / Q000737:chemistry*; D007166:Immunosuppressive Agents / Q000302:isolation & purification* / Q000494:pharmacology; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010714:Phosphatidylethanolamines / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D010714:Phosphatidylethanolamines