Antigenic relationship between the alpha-chain of C3, a leucocyte-surface antigen involved in the activation of phagocytic cells, and a 50,000 MW B-cell antigen.
A monoclonal antibody, M522, reacting with human monocytes, neutrophils and a proportion of non-adherent PBL in a pattern similar to OKM-1 and anti-Mo-1, and precipitating a dimer of MW 165,000 and 100,000 from neutrophils, was shown to react with C3 at an epitope localized on the alpha-chain of C3. F(ab)2-fragments of M522 stimulate the respiratory burst of neutrophils and monocytes. M522 differs from two monoclonal antibodies against the Mo-1 molecule with respect to the capacity to inhibit the binding of sheep erythrocytes coated with different C3-fragments to C-receptor carrying cells. It inhibited the binding of H-coated particles to B-lymphoid cells and precipitated a 50,000 MW molecule from RAJI cells and tonsil lymphocytes. The results obtained suggest an antigenic relationship between the alpha-chain of C3, the heavy chain of a membrane molecule involved in neutrophil/monocyte activation, and a B-cell molecule of MW 50,000.
Schulz
T F
TF
Scharfenberger
H
H
Lambris
J D
JD
Rieber
P
P
Riethmüller
G
G
Dierich
M P
MP
D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D001667:Binding, Competitive; D002478:Cells, Cultured; D003176:Complement C3 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D012397:Rosette Formation
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D003176:Complement C3; D000939:Epitopes; D008565:Membrane Proteins