Activation of Fc receptor-mediated phagocytosis by mouse peritoneal macrophages following the intraperitoneal administration of liposomes.
The effects of liposomes on the phagocytic activity of mouse peritoneal macrophages were investigated using IgG-opsonized sheep red blood cells (SRBC). The highest ingestion index of opsonized SRBC via Fc receptors of macrophages from BALB/c mice was observed for macrophages harvested on day 4 following the intraperitoneal injection of liposomes (2.27 mumol lipid/mouse). An increase in the ingestion index was observed irrespective of liposomal charge. Binding parameters of Fc receptors of macrophages from liposome- or saline-injected mice were determined using horseradish peroxidase-conjugated IgG, and an increase in the number of binding sites with the same binding constant was observed in macrophages from liposome-injected mice. The activation mechanism of mouse peritoneal macrophages by liposomes differed from that by lipopolysaccharides. Liposomes thus appear to contribute to the activation of immune response.
Aramaki
Y
Y
Tokyo College of Pharmacy, Japan.
Murai
M
M
Tsuchiya
S
S
D015060:1,2-Dipalmitoylphosphatidylcholine; D000818:Animals; D004912:Erythrocytes / Q000276:immunology / Q000502:physiology; D007074:Immunoglobulin G / Q000276:immunology; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis / Q000502:physiology*; D011961:Receptors, Fc / Q000502:physiology*; D012756:Sheep / Q000276:immunology
D007074:Immunoglobulin G; D008081:Liposomes; D009895:Opsonin Proteins; D011961:Receptors, Fc; D015060:1,2-Dipalmitoylphosphatidylcholine