Abstract
A variety of markers to differentiate the P phase virus from the Q phase virus among the population of A2 viruses have been proposed from this laboratory. They are as follows:
1) P virus is more avid to immune sera than Q virus, particularly in hemagglutination inhibition test using chicken red cells.
2) P virus is more sensitive to α′-inhibitors detectable in human plasma or in normal guinea pig serum.
3) Heat stability of hemagglutinins is higher with Q virus than P virus.
4) Bovine red cell agglutinins are detectable only with Q virus but not with P virus.
In this article, the fact that the activity of receptor destroying enzyme is higher with Q virus than P virus was added as the fifth marker.
In the second place, higher avidity of P virus than Q virus to immune sera was studied further in critical manner. The result revea ed the fact that in hemagglutination inhibition test with human convalescent sera, when human O red cells were used instead of chicken red cells, hemagglutinin inhibitory antibody was detectable even with Q virus as an antigen. Secondly, in the complement fixation test withboth viral antigens, there was no difference between P and Q in the avidity to fix the antibody contained in human convalescent sera. Thus the idea to assume P virus as in a indicator state of Q virus was proposed. In fact, KIO4 treatment of various Q viruses gave rise to the virus which was succeptible to human antibody and various inhibitors in hemagglutination inhibition test. Treatment of Q virus with formalin or urea did not change the characteristics of Q virus as KIO4. Trypsin treatment of both P and Q virus revealed the fact that they are both fairly resistant to this enzymatic action.
Bovine red cell agglutinin found with Q virus was assumed to be the marker associated to the virus particle, as a whole. Because it was easily lost with ether treatment and was not detectable with the small hemagglutinins derived from Q virus.
