title: Activation of NF-kappa B in human endothelial cells induced by monoclonal and allospecific HLA antibodies.
abstract: Chronic graft rejection, characterized by a gradual occlusion of grafted vessels, is the most serious complication following heart and kidney transplantation. Although often associated with chronic production of anti-HLA and anti-endothelial antibodies, the precise role of antibodies in chronic rejection remains uncertain. Here we have investigated whether HLA-specific antibodies, either monoclonal or derived from patients, cause endothelial cell activation. Thus we investigated tyrosine phosphorlyation, NF-kappaB activation and cell proliferation in human umbilical vein endothelial cells (HUVEC) or microvascular endothelial cells from adult human heart (CMEC). Ligation of monomorphic determinants of MHC class I molecules (using the mAb W6/32) on the surface of HUVEC caused an increase in tyrosine phosphorylation of proteins of mol. wt approximately 75-80 kDa. Similarly, ligation of monomorphic determinants on both CMEC and HUVEC resulted in increased NF-kappaB binding compared to controls (by 74.4 and 52.5%, P = 0.001) and this was enhanced by addition of secondary antibody. Two HLA-specific mAb resulted in a 277 and 170% increase in NF-kappaB-binding activity compared to controls. Four patient samples containing HLA antibodies were used against HLA-specific HUVEC and four samples were incubated with HUVEC bearing irrelevant antigens. Patient sera alone enhanced NF-kappaB binding by 27-186%, but only when added to HUVEC bearing relevant antigens. W6/32 and allospecific antibodies from patients significantly enhanced HUVEC proliferation, measured by uptake of [(3)H]thymidine. In conclusion, activation of NF-kappaB by human anti-HLA antibodies demonstrates their potential role in pathogenesis of chronic vascular occlusive disease following transplantation.
authors.affiliation: National Heart & Lung Institute, Imperial College School of Medicine, Harefield Hospital, Harefield, Middlesex UB9 6JH, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Smith
authors.forename: C
authors.initials: C
authors.lastname: Lawson
authors.forename: M H
authors.initials: MH
authors.lastname: Yacoub
authors.forename: M L
authors.initials: ML
authors.lastname: Rose
mesh_terms: D000328:Adult; D000483:Alleles; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000918:Antibody Specificity / Q000235:genetics; D000961:Antilymphocyte Serum / Q000494:pharmacology*; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D006801:Humans; D020672:I-kappa B Proteins; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000961:Antilymphocyte Serum; D004268:DNA-Binding Proteins; D006680:HLA Antigens; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D000072000:NF-KappaB Inhibitor alpha; D014443:Tyrosine