Biomaterial Database

Halogenation and proteolysis of complement component C3 on Salmonella typhimurium during phagocytosis by human neutrophils. 1989

K A Joiner, and J E Schweinle

Laboratory of Parastic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.

We examined the fate of C component C3 on the surface of Salmonella typhimurium during ingestion by human neutrophils. Initial experiments showed that C3 fragments and C3-acceptor complexes were the major serum ligands which were surface iodinated by canine myeloperoxidase on serum-incubated rough and smooth isolates of S. typhimurium. In contrast, labeled C3 was not identified when the same organisms were ingested by neutrophils in the presence of 125I-Na, a situation previously shown to iodinate particulate targets via the neutrophil myeloperoxidase-halide-H2O2 system. Pretreatment of neutrophils before phagocytosis with the lipid-soluble protease inhibitor diisopropylfluorophosphate (DFP), but not with other protease inhibitors (p-nitrophenylguanidinobenzoate, leupeptin, pepstatin), substantially blocked proteolysis of 125I-C3 on S. typhimurium strain RG108 during ingestion by neutrophils. Purification of neutrophil phagosomes containing S. typhimurium-bearing 125I-C3 showed that DFP but no other protease inhibitors blocked proteolysis of 125I-C3 within phagosomes. Iodinated C3-acceptor complexes were identified by immunoprecipitation from the detergent-insoluble fraction of phagosomes prepared from DFP-treated cells ingesting S. typhimurium in the presence of 125I-Na. These results show that C3 fragments on the surface of S. typhimurium are the major serum ligands which are halogenated and degraded by proteolysis during phagocytosis by human neutrophils, and suggest that the majority of proteolysis on the ingested target occurs within the neutrophil phagosome.

UI	MeSH Term	Description	Entries
D007455	Iodine	A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126.90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically.	Iodine-127,Iodine 127
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D009195	Peroxidase	A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.	Myeloperoxidase,Hemi-Myeloperoxidase,Hemi Myeloperoxidase
D009504	Neutrophils	Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.	LE Cells,Leukocytes, Polymorphonuclear,Polymorphonuclear Leukocytes,Polymorphonuclear Neutrophils,Neutrophil Band Cells,Band Cell, Neutrophil,Cell, LE,LE Cell,Leukocyte, Polymorphonuclear,Neutrophil,Neutrophil Band Cell,Neutrophil, Polymorphonuclear,Polymorphonuclear Leukocyte,Polymorphonuclear Neutrophil
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D011480	Protease Inhibitors	Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).	Antiprotease,Endopeptidase Inhibitor,Endopeptidase Inhibitors,Peptidase Inhibitor,Peptidase Inhibitors,Peptide Hydrolase Inhibitor,Peptide Hydrolase Inhibitors,Peptide Peptidohydrolase Inhibitor,Peptide Peptidohydrolase Inhibitors,Protease Antagonist,Protease Antagonists,Antiproteases,Protease Inhibitor,Antagonist, Protease,Antagonists, Protease,Hydrolase Inhibitor, Peptide,Hydrolase Inhibitors, Peptide,Inhibitor, Endopeptidase,Inhibitor, Peptidase,Inhibitor, Peptide Hydrolase,Inhibitor, Peptide Peptidohydrolase,Inhibitor, Protease,Inhibitors, Endopeptidase,Inhibitors, Peptidase,Inhibitors, Peptide Hydrolase,Inhibitors, Peptide Peptidohydrolase,Inhibitors, Protease,Peptidohydrolase Inhibitor, Peptide,Peptidohydrolase Inhibitors, Peptide
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man