title: Immunoliposome targeting to CD4+ cells in human blood.
abstract: Liposomes were prepared from phospholipid formulations recognized or ignored by cells of the reticuloendothelial system (RES+ve or RES-ve, respectively). The ability of these liposomes to interact with CD4+ve cells in purified leukocyte fractions or in whole blood has been determined. RES+ve liposomes bound to monocytes in purified leukocyte fractions or in whole blood, but did not bind to lymphocytes. RES-ve liposomes did not bind to either monocytes or lymphocytes. The attachment of an anti-Leu3A (CD4) monoclonal antibody to the outer surface of RES-ve liposomes resulted in their interaction with both monocytes and lymphocytes. The binding was blocked by prior incubation of the leukocytes with free anti-Leu3A antibody. RES+ve liposomes were rapidly eliminated from the circulation of mice after intravenous injection, whereas RES-ve liposomes remained in the circulation for prolonged periods of time (half-life much greater than 5 h), even after incubation with the opsinizing acute-phase reactant, C-reactive protein. These results suggest that RES-ve liposomes possessing surface-bound anti-Leu3A may provide a means of targeting antiviral agents to those cells at risk from HIV infection.
authors.affiliation: Montreal General Hospital Research Institute, Quebec, Canada.
authors.forename: N C
authors.initials: NC
authors.lastname: Phillips
authors.forename: C
authors.initials: C
authors.lastname: Tsoukas
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000276:immunology; D001360:Avidin; D001710:Biotin; D015704:CD4 Antigens / Q000276:immunology*; D006207:Half-Life; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008081:Liposomes / Q000493:pharmacokinetics*; D008297:Male; D008563:Membrane Lipids; D051379:Mice; D012157:Mononuclear Phagocyte System / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism / Q000493:pharmacokinetics*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D008081:Liposomes; D008563:Membrane Lipids; D010743:Phospholipids; D001360:Avidin; D001710:Biotin