title: Contribution of complement component C3 and complement receptor type 3 to carbohydrate-dependent uptake of oligomannose-coated liposomes by peritoneal macrophages.
abstract: Peritoneal macrophages (PEMs) preferentially and rapidly take up oligomannose-coated liposomes (OMLs) and subsequently mature to induce a Th-1 immune response following administration of OMLs into the peritoneal cavity. Here, we examine the contributions of complement component C3 and complement receptor type 3 (CR3) to carbohydrate-dependent uptake of OMLs by PEMs. Effective uptake of OMLs into PEMs in vitro was observed only in the presence of peritoneal fluid (PF), and OMLs incubated with PF were incorporated by PEMs in vitro in the absence of PF. These phenomena were inhibited by methyl-alpha-mannoside, N-acetylglucosamine or EDTA, but not by galactose. Pull-down analysis followed by peptide mass fingerprinting of PF-treated OMLs indicated that the OMLs were opsonized with complement fragment iC3b. In vivo uptake of OMLs by PEMs was inhibited by intraperitoneal injection of an antibody against CR3, a receptor for iC3b, and OML uptake by PEMs in the peritoneal cavity was not observed in C3-deficient mice. Thus, our results indicate that OMLs are opsonized with iC3b in a mannose-dependent manner in the peritoneal cavity and then incorporated into PEMs via CR3.
authors.affiliation: Department of Applied Biochemistry; Institute of Glycoscience, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Abe
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Noritaka
authors.initials: N
authors.lastname: Kuboki
authors.forename: Misao
authors.initials: M
authors.lastname: Matsushita
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yokoyama
authors.forename: Naoya
authors.initials: N
authors.lastname: Kojima
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000737:chemistry; D002478:Cells, Cultured; D003176:Complement C3 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D037181:Lectins, C-Type / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000378:metabolism*; D008358:Mannose / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010446:Peptide Fragments / Q000378:metabolism; D010449:Peptide Mapping
chemical_list: D003176:Complement C3; D037181:Lectins, C-Type; D008081:Liposomes; D016177:Macrophage-1 Antigen; D010446:Peptide Fragments; D008358:Mannose