Human protectin (CD59), an 18-20-kD homologous complement restriction factor, does not restrict perforin-mediated lysis.
Human protectin (CD59) is an 18-20-kD membrane glycoprotein that restricts lysis of human erythrocytes and leukocytes by homologous complement. By directly incorporating protectin into membranes of heterologous cells we observed that protectin did not prevent perforin-mediated killing, whereas complement killing was effectively restricted. Further, no significant enhancement of cell-mediated killing or target killing by purified perforin was observed with anti-protectin antibodies. Thus, in contrast with complement lysis, restriction of lysis by protectin does not apply to cell-mediated killing.
Meri
S
S
Molecular Immunopathology Unit, Medical Research Council, Cambridge, United Kingdom.
Morgan
B P
BP
Wing
M
M
Jones
J
J
Davies
A
A
Podack
E
E
Lachmann
P J
PJ
D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000502:physiology*; D000943:Antigens, Differentiation / Q000502:physiology*; D018957:CD59 Antigens; D003165:Complement System Proteins / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D006168:Guinea Pigs; D006461:Hemolysis / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008562:Membrane Glycoproteins / Q000502:physiology*; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011817:Rabbits
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018957:CD59 Antigens; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D003165:Complement System Proteins