Activation of the alternative pathway of human complement by autologous cells expressing transmembrane recombinant properdin.

Détails

ID Serval
serval:BIB_15068
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Activation of the alternative pathway of human complement by autologous cells expressing transmembrane recombinant properdin.
Périodique
Molecular Immunology
Auteur⸱e⸱s
Vuagnat B.B., Mach J., Le Doussal J.M.
ISSN
0161-5890
Statut éditorial
Publié
Date de publication
2000
Volume
37
Numéro
8
Pages
467-478
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't Publication Status: ppublish
Résumé
Properdin (P) is a serum glycoprotein that stabilizes the labile C3 convertase (C3bBb) of the alternative pathway of the complement system (AP). Thanks to its oligomeric nature, P specifically upregulates AP on surfaces without activating AP in the fluid-phase. We investigated whether human cells, displaying P at their membrane, could activate autologous AP. The cDNAs encoding human P and the transmembrane domain of human platelet derived growth factor receptor were fused together and expressed in human embryo kidney cells (HEK-293). Selected cells displayed P at their surface as shown by FACS. In contact with human serum at 37 degrees C, they triggered AP-mediated C3 deposition. SDS-PAGE analysis showed C3 covalently bound to various membrane proteins, but not to P itself. However, displayed P affinity could bind to serum or purified C3i at 4 degrees C. C3 binding was restricted to the cells displaying P, was inhibited by an anti-P mAb, and did not require serum P. Bound C3 allowed further C5, C7 and C9 deposition as well as cell lysis after blocking CD59 function. In contrast, wild-type cells, cells displaying factor D or truncated P (deleted from its 6th thrombospondin-like repeat) did not activate AP. We hypothesize that displayed P activates AP by stabilizing bystander C3b and/or by capturing serum C3iBb convertase. Finally, we suggest that P could be used for retargeting autologous complement to AP-resistant pathogens and tumor cells.
Mots-clé
Amino Acid Sequence, Antibodies/immunology, Antibodies/pharmacology, Antigens, CD/analysis, Cell Line, Cell Membrane/metabolism, Complement C3/immunology, Complement C3/metabolism, Complement Factor D/immunology, Complement Pathway, Alternative/immunology, Cytotoxicity, Immunologic, Diffusion, Electrophoresis, Polyacrylamide Gel, Flow Cytometry, Fluorescent Antibody Technique, Gene Expression, Humans, Membrane Proteins/chemistry, Membrane Proteins/genetics, Models, Immunological, Molecular Sequence Data, Properdin/chemistry, Properdin/genetics, Protein Binding/drug effects, Receptors, Platelet-Derived Growth Factor/chemistry, Receptors, Platelet-Derived Growth Factor/genetics, Recombinant Fusion Proteins/chemistry, Recombinant Fusion Proteins/genetics, Sequence Deletion, Solubility, Substrate Specificity, Transfection
Pubmed
Web of science
Création de la notice
19/11/2007 12:07
Dernière modification de la notice
20/08/2019 12:43
Données d'usage