Vesicular stomatitis virus (VSV) in mixed infection with Sindbis virus (SbV) produces a proportion of phenotypically mixed particles (pseudotypes) containing VSV genomes and neutralization antigen(s) provided by SbV. This was demonstrated by heat-stabilization of the thermolabile tlB17 mutant of VSV and by neutralization with corresponding antisera. Phenotypic mixing is apparently unilateral because no SbV(VSV) pseudotypes could be found. Similarly, avian RNA tumour virus (ATV) in mixed infection with Sindbis virus produces a proportion of phenotypically mixed particles containing ATV genomes and SbV antigens, but no detectable particles containing SbV genomes and ATV envelope antigens. SbV acts as a helper virus for envelope-defective Rous sarcoma virus (RSV). When an avian helper virus is also present in the mixed infection, more than 90% of the RSV particles bearing SbV envelope antigens also bear ATV envelope antigens and are doubly neutralizable by antisera specific to either parent virus. In mixed infection of Langat virus and VSV, a proportion of doubly neutralizable particles containing VSV genomes were produced, but no pure pseudotypes. These results indicate that in mixed infections between enveloped animal viruses, VSV and ATV readily assemble foreign envelope glycoproteins, but that SbV does not. In certain phenotypically mixed virus stocks, only doubly neutralizable particles are found and are presumed to bear a mosaic of envelope antigens; in other stocks, particles can also be detected which are resistant to neutralization by antiserum specific to the envelope antigen encoded by their genomes, and these are presumed to represent pure pseudotypes.
ChoppinP. W.,
CompansR. W.1970; Phenotypic mixing of envelope proteins of the parainfluenza virus SV5 and vesicular stomatitis virus. Journal of Virology 5:609–616
DulbeccoR.,
VogtM.,
StricklandA. G. R.1956; A study of the basic aspects of neutralization of two animal viruses, Western equine encephalitis virus and poliomyelitis virus. Virology 2:162–205
HuangA. S.,
BesmerP.,
ChuL.,
BaltimoreD.1973; Growth of pseudotypes of vesicular stomatitis virus with N-tropic murine leukemia virus coats in cells resistant to N-tropic viruses. Journal of Virology 12:659–662
KrontirisT. G.,
SoeiroR.,
FieldsB. N.1973; Host restriction of Friend leukemia virus. Role of the viral outer coat. Proceedings of the National Academy of Sciences of the United States of America 70:2549–2553
LagwinskaE.,
StewartC. C.,
AdlesC.,
SchlesingerS.1975; Replication of lactic dehydrogenase virus and Sindbis virus in mouse peritoneal macrophages. Induction of interferon and phenotypic mixing. Virology 65:204–214
LivingstonD. M.,
HowardT.,
SpenceC.1976; Identification of infectious virions which are vesicular stomatitis virus pseudotypes of murine type C virus. Virology 70:432–439
MarcusP. L.,
SekellickM. J.1975; Cell killing by viruses. II. Cell killing by vesicular stomatitis virus: a requirement for virion-derived transcription. Virology 63:176–190
MayerV.1974; A live vaccine against tick-borne encephalitis: integrated studies. I. Basic properties and behaviour of the E15 ‘14’ clone (Langat virus). Acta Virologica 19:209–218
McsharryJ. J.,
CompansR. W.,
ChoppinP. W.1971; Proteins of vesicular stomatitis virus and of pheno-typicaliy mixed vesicular stomatitis virus-simian virus 5 virions. Journal of Virology 8:722–729
WeissR. A.1969; Interference and neutralization studies with Bryan strain Rous sarcoma virus synthesized in the absence of helper virus. Journal of General Virology 5:529–539
WeissR. A.,
BoettigerD. E.,
MurphyH. M.1977; Pseudotypes of avian sarcoma viruses with the envelope properties of vesicular stomatitis virus. Virology 76:808–825
ZavadaJ.1972a; Pseudotypes of vesicular stomatitis virus with the coat of murine leukaemia and of avian myeloblastosis viruses. Journal of General Virology 15:183–191
ZavadaJ.,
ZavodskaE.1973/74; Complementation and phenotypic stabilization of vesicular stomatitis virus temperature-sensitive and thermo-labile mutants by avian myeloblastosis virus. Intervirology 2:25–32