title: The in vitro and in vivo effects of anti-galactose antibodies on endothelial cell activation and xenograft rejection.
abstract: We have previously produced a series of antigalactose (anti-Gal) hybridomas and characterized their heavy chain gene usage. Here we have quantified the affinity of these Abs for the alpha-Gal epitope and characterized their in vitro effects on endothelial cell activation and apoptosis. We report that anti-Gal mAbs derived from Gal(-/-) mice show a range of affinity for the alpha-Gal epitope, and that affinity was generally increased as the V(H) gene usage transitioned from germline sequences to sequences exhibiting somatic maturation. Despite an 85-fold range in affinity, all the anti-Gal mAbs examined induced alpha-Gal-specific endothelial cell activation, and after prolonged exposure induced endothelial cell apoptosis in a complement-independent manner. Only murine anti-Gal mAbs of the IgM or IgG3 subclass, but not IgG1, were effective at initiating complement-dependent cell lysis. Using a novel rat to mouse xenograft model, we examined the in vivo ability of these mAbs to induce xenograft rejection and characterized the rejection using histology and immunohistochemistry. Infusion of complement-fixing IgG3 mAbs resulted in either hyperacute rejection or acute vascular rejection of the xenograft. Surprisingly, infusion of an equal amount of a high affinity anti-Gal IgG1 mAb, that fixed complement poorly also induced a rapid xenograft rejection, which we have labeled very acute rejection. These studies emphasize the importance of in vivo assays, in addition to in vitro assays, in understanding the role of anti-Gal IgG-mediated tissue injury and xenograft rejection.
authors.affiliation: Nextran, Princeton, NJ 08540, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Dengping
authors.initials: D
authors.lastname: Yin
authors.forename: Bashoo
authors.initials: B
authors.lastname: Naziruddin
authors.forename: Libing
authors.initials: L
authors.lastname: Chen
authors.forename: Aileen
authors.initials: A
authors.lastname: Stark
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wei
authors.forename: Ying
authors.initials: Y
authors.lastname: Lei
authors.forename: JiKun
authors.initials: J
authors.lastname: Shen
authors.forename: John S
authors.initials: JS
authors.lastname: Logan
authors.forename: Guerard W
authors.initials: GW
authors.lastname: Byrne
authors.forename: Anita S-F
authors.initials: AS
authors.lastname: Chong
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology*; D000915:Antibody Affinity / Q000235:genetics; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D001666:Binding Sites, Antibody / Q000235:genetics; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics; D004187:Disaccharides / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism; D006084:Graft Rejection / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D016027:Heart Transplantation / Q000276:immunology / Q000473:pathology; D006801:Humans; D006825:Hybridomas; D007275:Injections, Intravenous; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins; D051381:Rats; D011917:Rats, Inbred Lew; D013552:Swine; D014183:Transplantation, Heterologous / Q000276:immunology* / Q000473:pathology; D016042:Transplantation, Heterotopic / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D004268:DNA-Binding Proteins; D004187:Disaccharides; D009687:Nuclear Proteins; C499311:RAG2 protein, human; C499308:Rag2 protein, mouse; C064655:V(D)J recombination activating protein 2; C055075:galactosyl-(1-3)galactose