Studies on the mechanism of phagocytes for elimination of foreign cells
| Project/Area Number |
60480458
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Hokkaido University |
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Principal Investigator |
KOYAMA Jiro Professor, Hokkaido Univ. Faculty of Pharm. Sci., 薬学部, 教授 (10025679)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Tohoru Instructor, Hokkaido Univ. Faculty of Pharm. Sci., 薬学部, 助手 (30001978)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1985: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Macrophage / Polymorphonuclear leukocyte / NADPH oxidase / Active oxygen / Serine protease / Phagocytosis / NADPH-cytochrome c reductase / Fcレセプター |
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| Research Abstract |
Studies on the molecular mechanism of phagocytes for elimination of foreign or antigenic cells have been performed with guinea pig and pig polymorphonuclear leukocytes and also with guinea pig macrophages. The main results obtained are as follows. 1. When phagocytes encounter appropriate stimuli such as immune complexes, they promote <O(^-_2)> -generation. The results obtained suggest strongly that the NADPH oxidase responsible for the reaction may be composed of a membrane-bound NADPH-cytochrome c reductase and cytochrome <b_(-245)> , and exhibits its <O(^-_2)> -generating activity when the reductase forms an enzyme complex with cytochrome <b_(-245)> on the stimulation of cells. In fact, the highly purified reductase was found to generate <O(^-_2)> when reacted with partially purified cytochrome <b_(-245)> in the presence of phospholipids. 2. Sheep erythrocytes were found to be hemolyzed by incubation with the membrane fraction isolated from guinea pig macrophages and NADPH. The hemolytic factor formed was shown to be certain phospholipids in the membrane fraction peroxidized by the active oxygen species formed by the membrane-bound NADPH oxidase. 3. The triggering reactions by immune complexes for elicitation of <O(^-_2)> -generation and formation of the phagosomes in phagocytes are known to be inhibited with diisopropyl fluorophosphate, suggesting the involvement of a certain serine protease therein. A membrane-bound serine protease with a molecular weight of 40,000 was isolated from guinea pig polymorphonuclear leukocytes. Since the protease is bound to the Fc receptors of the cells and becomes to be labeled with [ <^3H> ] diisopropyl fluorophosphate on stimulation of the cells with immune complexes, it seems very probable that the protease participates in the triggering mechanism of cells for activation of the NADPH oxidase and formation of the phagosomes.
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Report
(1 results)
Research Products
(11 results)
