Possible Occurrence of Multiple Antigens in Type 2 Poliomyelitis and GDVII Mouse Encephalomyelitis Viruses.

There are several possibilities which may account for complement fixing activity present in the supernatants of acetone-ether but not in saline-ether extracts of MEF1 infant mouse virus obtained by centrifugation at 35000 rpm for 75 minutes. The acetone-ether extraction not only inactivates a large amount of infectivity, but at the same time decreases the density of such inactivated virus or breaks down a portion of the virus particles into smaller units. The CF activity of the supernatant, on the other hand, may represent a second antigen evident with acetone-ether but not saline-ether extracts because of concentration effects. In addition, it is possible that acetone-ether but not saline-ether treatment releases from the virus particles a second antigen. Finally, inhibitor substance(s) which partially interfere with CF activity of MEF1 virus may be removed by acetone-ether treatment. With GDVII virus it would appear that a physical separation of 2 CF antigens was realized, one associated with infectivity and hemagglutination, and the other of smaller size with comparatively little or no infectivity and hemagglutinating activity. Studies are now in progress to determine whether the supernatant CF activity of MEF1 acetone-ether extract antigen represents an antigen qualitatively different from the sediment fraction and also to obtain further evidence for the multiplicity of antigens in GDVII mouse encephalomyelitis virus.