Sendai virus haemolysis: mechanism of the increased haemolysis obtained by pretreatment of the virus with antibody and complement.

Abstract

Sendai virus is haemolytic against erythrocytes from various species. Pretreatment of the virus with antibody and complement (C) resulted in a sixfold increase in the haemolysis. The viral haemolysin (HL) could be inactivated by heating the virus at 37 degrees C for 5 h. HL-inactivated virus became haemolytic again when pre-treated with antibody and C. This acquired haemolytic capacity corresponded to the enhanced haemolysis shown by intact virus. It is concluded that the enhanced haemolytic activity is due to a C-mediated indirect haemolysis and is not dependent on the fusion process. The possibility of cell damage in vivo from virus-antibody-C complexes is discussed.