Identification of an immunodominant functional domain on human CD36 antigen using human-mouse chimaeric proteins and homologue-replacement mutagenesis.
The human CD36 antigen is a multifunctional membrane glycoprotein that acts as a receptor for thrombospondin, malaria-infected erythrocytes and oxidized low-density lipoprotein, as well as being implicated in the recognition of apoptotic neutrophils by macrophages. OKM5 and other anti-CD36 monoclonal antibodies have been shown to inhibit these CD36 adhesive functions, suggesting that the monoclonal-antibody epitopes and the domains that mediate these events are closely related. Analysis of a series of chimaeric exchanges between human and mouse CD36 shows that six anti-CD36 monoclonal antibodies (OKM5, FA6-152, L103, 5F1, SM phi and 10/5) recognize epitopes within the domain comprising amino acids 155-183. A seventh monoclonal antibody (13/10) binds to another domain that spans amino acids 30-76. Homologue-replacement mutagenesis performed within the human 155-183 immunodominant sequence identifies key residues for the binding of three functional monoclonal antibodies (OKM5, FA6-152 and L103). The fact that antibodies directed against the 155-183 domain can inhibit adhesion suggests that this domain is directly involved in CD36-ligand binding.
Daviet
L
L
INSERM Unit 331, Faculty of Medicine Alexis Carrel, Lyon, France.
Buckland
R
R
Puente Navazo
M D
MD
McGregor
J L
JL
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000235:genetics / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D018955:CD36 Antigens; D006801:Humans; D016056:Immunodominant Epitopes / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018955:CD36 Antigens; D016056:Immunodominant Epitopes; D011993:Recombinant Fusion Proteins