Mokola virus glycoprotein and chimeric proteins can replace rabies virus glycoprotein in the rescue of infectious defective rabies virus particles.
A reverse genetics approach which allows the generation of infectious defective rabies virus (RV) particles entirely from plasmid-encoded genomes and proteins (K.-K. Conzelmann and M. Schnell, J. Virol. 68:713-719, 1994) was used to investigate the ability of a heterologous lyssavirus glycoprotein (G) and chimeric G constructs to function in the formation of infectious RV-like particles. Virions containing a chloramphenicol acetyltransferase (CAT) reporter gene (SDI-CAT) were generated in cells simultaneously expressing the genomic RNA analog, the RV N, P, M, and L proteins, and engineered G constructs from transfected plasmids. The infectivity of particles was determined by a CAT assay after passage to helper virus-infected cells. The heterologous G protein from Eth-16 virus (Mokola virus, lyssavirus serotype 3) as well as a construct in which the ectodomain of RV G was fused to the cytoplasmic and transmembrane domains of the Eth-16 virus G rescued infectious SDI-CAT particles. In contrast, a chimeric protein composed of the amino-terminal half of the Eth-16 virus G and the carboxy-terminal half of RV G failed to produce infectious particles. Site-directed mutagenesis was used to convert the antigenic site III of RV G to the corresponding sequence of Eth-16 G. This chimeric protein rescued infectious SDI-CAT particles as efficiently as RV G. Virions containing the chimeric protein were specifically neutralized by an anti-Eth-16 virus serum and escaped neutralization by a monoclonal antibody directed against RV antigenic site III. The results show that entire structural domains as well as short surface epitopes of lyssavirus G proteins may be exchanged without affecting the structure required to mediate infection of cells.
Federal Research Centre for Virus Diseases of Animals, Tübingen, Germany.
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D000956:Antigens, Viral / Q000737:chemistry; D001483:Base Sequence; D003001:Cloning, Molecular; D003673:Defective Viruses / Q000737:chemistry; D005796:Genes; D018114:Lyssavirus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development; D008562:Membrane Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D011820:Rabies virus / Q000737:chemistry* / Q000254:growth & development; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014760:Viral Fusion Proteins / Q000235:genetics / Q000502:physiology*; D014765:Viral Vaccines / Q000737:chemistry*; D014779:Virus Replication
D000956:Antigens, Viral; D008562:Membrane Glycoproteins; C080824:Mokola virus glycoprotein vaccine; D011993:Recombinant Fusion Proteins; D014760:Viral Fusion Proteins; D014765:Viral Vaccines