title: Bovine polymorphonuclear cells passively acquire membrane lipids and integral membrane proteins from apoptotic and necrotic cells.
abstract: Immune cells can acquire membrane fragments and integral membrane proteins from dead and dying cells or in the case of immature dendritic cells, from live cells. While investigating the possibility that bovine polymorphonuclear cells (PMNs) might present antigen, coculture assays confirmed that integral membrane proteins were transferred rapidly and efficiently to bovine PMNs from a variety of apoptotic and necrotic cells. Specifically, we observed that PMNs rapidly acquired proteins such as major histocompatibility complex (MHC) class II and CD3 from a variety of syngeneic, allogeneic, and xenogeneic cell types. Such acquisition occurred within 40 min of PMN coculture with isolated peripheral blood mononuclear cells, and this acquisition occurred with equal efficiency at 4 degrees C and 37 degrees C. The transfer of murine MHC class II to bovine PMNs precluded the possibility of endogenous protein expression. We also demonstrated the transfer of fluorescently labeled plasma membrane lipids and biotinylated integral membrane proteins. Collectively, these observations support the hypothesis that membrane protein transfer was mediated by the fusion of membrane fragments or microvesicles with the PMN plasma membrane and not by phagocytosis of cell fragments. These observations indicate that phenotypic studies of PMNs must consider circumstances whereby PMNs may passively acquire membrane lipids and a variety of integral membrane proteins from dead or dying cells.
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK, S7N 5E3, Canada.
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Whale
authors.forename: Terry K
authors.initials: TK
authors.lastname: Beskorwayne
authors.forename: Lorne A
authors.initials: LA
authors.lastname: Babiuk
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Griebel
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism*; D017209:Apoptosis; D001402:B-Lymphocytes / Q000737:chemistry; D019921:Biotinylation; D017252:CD3 Complex / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured / Q000737:chemistry / Q000187:drug effects / Q000528:radiation effects; D018920:Coculture Techniques; D016895:Culture Media, Serum-Free; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000737:chemistry; D005456:Fluorescent Dyes; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008563:Membrane Lipids / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009336:Necrosis; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D012756:Sheep; D013045:Species Specificity; D013601:T-Lymphocytes / Q000737:chemistry
chemical_list: D017252:CD3 Complex; D016895:Culture Media, Serum-Free; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D008070:Lipopolysaccharides; D008563:Membrane Lipids; D008565:Membrane Proteins; D011994:Recombinant Proteins; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor