title: Activation of the alternative complement pathway by IgM antibody reacted on paragloboside incorporated into liposome membrane.
abstract: Liposomes containing paragloboside (PG) on their membrane were readily lysed by C4 deficient guinea pig serum (C4D-GPS). On the other hand, guinea pig serum from specific pathogen free Hartley guinea pigs (SPF-GPS) did not lyse PG-liposomes in Mg-EGTA-GVB (gelatin veronal buffered saline containing MgCl2 and ethyleneglycol-bis(beta-aminoethyl ether)N,N'-tetraacetate) which permits complement activation via the alternative pathway but not via the classical pathway. However, the SPF-GPS could lyse the liposomes in Mg-EGTA-GVB when heated (56 degrees C, 30 min) C4D-GPS or other guinea pig serum (GPS) was added. Gel filtration of Hartley (Htl)-GPS through a Sephadex G-200 column revealed that IgM antibody to PG in Htl-GPS was responsible for sensitization of the liposomes to lysis by complement of SPF-GPS via the alternative pathway. This result indicated that guinea pig IgM antibody can initiate the activation of the alternative pathway of homologous complement on liposome membrane.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D003167:Complement Activation; D003170:Complement Pathway, Alternative; D005915:Globosides / Q000276:immunology*; D006028:Glycosphingolipids / Q000276:immunology*; D006168:Guinea Pigs; D007075:Immunoglobulin M / Q000276:immunology*; D008081:Liposomes / Q000276:immunology*; D008563:Membrane Lipids / Q000276:immunology
chemical_list: D005915:Globosides; D006028:Glycosphingolipids; D007075:Immunoglobulin M; D008081:Liposomes; D008563:Membrane Lipids; C036363:paragloboside