title: Inhibition of phagocytosis by rainbow trout (Oncorhynchus mykiss) macrophages by botulinum C2 toxin and its trypsinized component II.
abstract: Botulinum C2 toxin (C2T) is composed of two nonlinked protein components, components I and II. The toxin reconstituted with component I and trypsinized component II inhibited phagocytosis of rainbow trout (Oncorhynchus mykiss) and mouse macrophages. Inhibition in both cell types was observed over a range of toxin concentrations that were not toxic to the cells. Because cytoplasmic action of rainbow trout macrophages is ADP-ribosylated by component I, the inhibition of phagocytosis in trout cells by C2T is probably due to inactivation of cytoplasmic actin. Moreover, phagocytosis by trout cells was also inhibited in a dose-dependent manner by trypsinized component II alone, and did not cause cell death. The present results show that the macrophages of aquatic vertebrates are susceptible to C2T, and that trypsinized component II elicits a novel biological activity by binding to the cell membrane of the macrophages.
authors.affiliation: Laboratory of Veterinary Immunology, College of Agriculture, University of Osaka Prefecture, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kodama
authors.forename: T
authors.initials: T
authors.lastname: Baba
authors.forename: I
authors.initials: I
authors.lastname: Ohishi
mesh_terms: D000199:Actins / Q000037:antagonists & inhibitors; D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001905:Botulinum Toxins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008221:Lymphoid Tissue / Q000166:cytology; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000502:physiology; D051379:Mice; D017686:Oncorhynchus mykiss / Q000276:immunology*; D010446:Peptide Fragments / Q000187:drug effects; D010587:Phagocytosis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011485:Protein Binding; D013045:Species Specificity; D014357:Trypsin / Q000494:pharmacology
chemical_list: D000199:Actins; D010446:Peptide Fragments; D011065:Poly(ADP-ribose) Polymerases; D014357:Trypsin; D001905:Botulinum Toxins