Abstract |
C3e is a leukocytosis-inducing peptide of degraded C3 that has the electrophoretic behavior of prealbumin and a MW of 10-12,000. Using a homogeneous preparation, the ability of C3e to promote lysosomal enzyme release from human polymorphonuclear leukocytes (PMNs) was examined by incubation of various concentrations of C3e with cytochalasin B-treated (5 micrograms/ml) human PMNs for 60 min at 37 degrees C. Amounts of extracellular beta-glucuronidase, myeloperoxidase, and lysozyme were determined in the cell-free supernatants and it was found that all three enzymes were released in significant amounts without concomitant release of the cytoplasmic enzyme lactate dehydrogenase (LDH). At a concentration of 25 micrograms/ml of C3e, 25 +/- 1.1% (SD) of lysozyme, 20 +/- 0.9% beta-glucuronidase, and 24.3 +/- 0.9% myeloperoxidase were released into the supernatant while the release of LDH remained within the 4-7% range throughout these studies. Furthermore the supernatants were found to contain a substance which was capable of a generating chemotactic fragment from isolated C5. The same range of C3e concentrations (5-25 micrograms/ml) was, however, incapable of effecting histamine release from basophils. These results suggest that generation of C3e in vivo may serve as a potent stimulus for the generation of the C5-cleaving enzyme from PMNs which in turn may function to recruit more neutrophils by a positive feedback mechanism.
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Authors | B Ghebrehiwet |
Journal | Clinical immunology and immunopathology
(Clin Immunol Immunopathol)
Vol. 30
Issue 2
Pg. 321-9
(Feb 1984)
ISSN: 0090-1229 [Print] United States |
PMID | 6198120
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Complement C3
- Macrophage-1 Antigen
- Peptide Fragments
- Receptors, Complement
- complement C3e
- Complement C3b
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Topics |
- Basophils
(immunology)
- Chemotaxis, Leukocyte
- Complement C3
(metabolism, physiology)
- Complement C3b
- Dose-Response Relationship, Immunologic
- Histamine Release
- Humans
- Lysosomes
(enzymology)
- Macrophage-1 Antigen
- Neutrophils
(enzymology, immunology, metabolism)
- Peptide Fragments
(physiology)
- Receptors, Complement
(metabolism)
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