Expression of the complement regulator factor C8 binding protein on human glomerular cells protects them from complement-mediated killing.
The complement-regulatory factor C8 binding protein (C8bp) was first identified on human erythrocyte membranes by its affinity for the complement component C8 and its ability to inhibit lysis by homologous complement. Cultured human glomerular mesangial or epithelial cells (GEC) expressed C8bp on the cell surface and in the cytoplasm. Following stimulation of the glomerular cells with interleukin 1 beta, C5b-9 or with endotoxin, a transient, protein synthesis-independent increase in C8bp surface expression was seen. Blocking of C8bp function with F(ab)2 fragment of an antibody to C8bp rendered GEC susceptible to complement-mediated killing, indicating that C8bp contributes to the cellular defense against complement attack.
Schieren
G
G
Institut für Immunologie, Universität Heidelberg, Deutschland.
Schönermark
M
M
Braunger
M
M
Hänsch
G M
GM
D001798:Blood Proteins / Q000032:analysis* / Q000502:physiology; D018957:CD59 Antigens; D002352:Carrier Proteins / Q000032:analysis* / Q000502:physiology; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D003167:Complement Activation / Q000502:physiology; D003182:Complement C5 / Q000494:pharmacology; D050776:Complement C5b; D003165:Complement System Proteins / Q000494:pharmacology*; D004731:Endotoxins / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005920:Glomerular Mesangium / Q000737:chemistry* / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007678:Kidney Glomerulus / Q000737:chemistry / Q000166:cytology
D001798:Blood Proteins; D018957:CD59 Antigens; D002352:Carrier Proteins; D003182:Complement C5; D004731:Endotoxins; D007375:Interleukin-1; C051590:CD59 protein, human; D050776:Complement C5b; D003165:Complement System Proteins