Studies on the soluble antigen of influenza virus: II. A comparison of the effects of sonic vibration and ether treatment of elementary bodies

Abstract

A comparison was made of the effects of sonic vibration and of exposure to ether on the release of S antigen from influenza virus. Elementary body suspensions (EB) obtained by high-speed centrifugation or by one cycle of adsorption onto and elution from red cells frequently reacted directly with anti-S sera. The presence of such “external” S depended upon the length of in ovo incubation and upon the strain of virus employed. Following sonic vibration the S titers increased in the EB preparations which initially revealed some S activity, and antigen became detectable in those originally free of measurable quantities. After sonic vibration or even only after second adsorption-elution cycles, the EB suspensions, as a rule, failed to react with anti-S. Although the data indicate that sonic vibration liberated some internal S, its release was not immediately accompanied by detectable losses in infectivity nor was a change noted in the degree of sedimentation of the virus particles by high-speed centrifugation. In any event, exposure to ether proved to be a more potent means of releasing internal S than sonic vibration since no additional S was liberated from ether-treated virus by the latter technique, whereas, in contrast, sonically vibrated EB suspensions on treatment with ether yielded apparently as much S as untreated virus particles. The implications of these results have been discussed.