title: Cooperation of specific ICAM-3 grabbing nonintegrin-related 1 (SIGNR1) and complement receptor type 3 (CR3) in the uptake of oligomannose-coated liposomes by macrophages.
abstract: Resident peritoneal macrophages (PEMs) express SIGNR1 on the cell surface as a major mannose receptor. These cells also ingest oligomannose-coated liposomes (OMLs) in an oligomannose-dependent manner following intraperitoneal administration. Therefore, the current study was conducted to investigate the possible role of SIGNR1 in capture of OMLs. Transient expression of several SIGN-related lectins potentially expressed on PEMs in CHO cells revealed that only SIGNR1 contributed to capture of OMLs. When SIGNR1 was introduced into mouse macrophage-like RAW264.7 cells, SIGNR1-expressing RAW (RAW-SIGNR1) cells recognized OMLs under serum-free conditions. OML recognition by RAW-SIGNR1 cells as well as that by PEMs was partially inhibited by an anti-SIGNR1 antibody (ER-TR9) and by mannan, and completely inhibited by EDTA. Interestingly, OML recognition by RAW-SIGNR1 cells was accelerated in the presence of serum, partially inhibited by an anti-complement receptor 3 (CR3) antibody (M1/70), and almost completely inhibited by a combination of ER-TR9 and M1/70. Complete inhibition of OML ingestion by the combination of ER-TR9 and M1/70 was also observed under serum-free conditions, suggesting that SIGNR1 and CR3 cooperate in an additive way in capture of OMLs by macrophage-like RAW cells. Administration of ER-TR9 or M1/70 into the peritoneal cavity led to a significant decrease of OML uptake by PEMs. Therefore, SIGNR1 expressed on macrophages acts as a receptor for recognition of OMLs under physiological conditions.
authors.affiliation: Institute of Glycoscience, Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takagi
authors.forename: Maki
authors.initials: M
authors.lastname: Numazaki
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Kajiwara
authors.forename: Yu
authors.initials: Y
authors.lastname: Abe
authors.forename: Mariko
authors.initials: M
authors.lastname: Ishii
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Naoya
authors.initials: N
authors.lastname: Kojima
mesh_terms: D000818:Animals; D016466:CHO Cells; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism*; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000235:genetics / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000378:metabolism*; D008358:Mannose / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014162:Transfection; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015815:Cell Adhesion Molecules; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D037181:Lectins, C-Type; D008081:Liposomes; D016177:Macrophage-1 Antigen; D008358:Mannose; D011956:Receptors, Cell Surface; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin