Regulatory control of the terminal complement proteins at the surface of human endothelial cells: neutralization of a C5b-9 inhibitor by antibody to CD59

摘要: Functionally inhibitory antibody to the plasma membrane complement inhibitor CD59 has been used investigate control of terminal proteins at endothelial cell surface. Antibodies against purified human erythrocyte (polyclonal anti-CD59 and monoclonal antibodies [MoAbs] 1F1 1F5) were found bind specifically monolayers cultured umbilical vein cells, by Western blotting recognize an 18- 21-Kd protein. When bound monolayer, (immunoglobulin G or Fab fragment) potentiated pore formation induced upon C9 binding C5b-8, augmented C5b-9-induced cellular responses, including stimulated secretion von Willebrand factor expression catalytic surface for prothrombinase enzyme complex. Although potentiating responses proteins, had no effect on response these cells stimulation histamine. Taken together, data suggest that express which serves protect from pore-forming cell-stimulatory effects C5b-9 These also inactivation deletion this regulatory molecule would increase likelihood procoagulant changes in endothelium exposed activation plasma.