Evidence for the Absence of Anaphylactogenic Host Protein in Highly Purified PR8 Influenza Virus

Abstract

Summary The anaphylactogenic properties of crude sedimented and highly purified PR8 influenza virus suspensions were investigated by the Schultz-Dale reaction with excised uterine muscle from sensitized guinea pigs. It was shown that the specificity of the in vitro anaphylactic reaction with crude sedimented virus is related to the host protein present in the virus suspensions and not to the specific viral antigen. When PR8 influenza virus was concentrated from infected chorioallantoic fluid by one cycle of ultracentrifugation or by one cycle of adsorption and elution from chicken erythrocytes, the presence of host protein could readily be detected by Schultz-Dale reactions with uterine muscle taken from guinea pigs previously sensitized with normal chorioallantoic membrane antigen, but, when the first cycle eluates were further purified by a second cycle of adsorption and elution from guinea pig erythrocytes, host material could be detected in only trace amounts in two separate virus suspensions. Finally, sedimentation of the second cycle eluates in the ultracentrifuge yielded two preparations which contained no detectable amount of host protein. The data presented in this investigation appear to be irreconcilable with the hypothesis that normal anaphylactogenic host protein is incorporated on the surface of the PR8 influenza virus elementary body during replication in the chorioallantois of the embryonated egg.