Characterization of street rabies virus variants with an additional N-glycan at position 247 in the glycoprotein.
Most street rabies virus glycoproteins (G proteins) possess two N-glycosylation sites, at Asn(37) and Asn(319), whereas an additional N-glycosylation site is present in several fixed (laboratory-adapted) rabies virus strains at Asn(247), which suggests that the N-glycosylation addition may be a marker of fixed viruses. In this study, we successfully cloned two street virus strain 1088 variants, N5B#15 and N5B#10-28, in which the G proteins had an additional N-glycan at position 247, and we examined whether these variants were characterized by cell culture adaptation and attenuation after intramuscular inoculation as fixed viruses. N5B#15 had four mutations, i.e., S148P and D247N in the G protein, and T137A and N2046S in the large (L) protein. N5B#10-28 had an additional mutation in the G protein, R196I. Compared with the parental 1088 virus, both variants exhibited highly efficient replication in mouse neuroblastoma-derived NA cells and reduced pathogenicity in adult mice when inoculated intramuscularly, but not intracerebrally. However, this attenuation was not attributable to the induction of strong immune responses.
Research Promotion Institute, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan, kentaro-y@oita-u.ac.jp.
Kentaro
K
Yamada
Kazuko
K
Noguchi
Akira
A
Nishizono
D000818:Animals; D000956:Antigens, Viral / Q000737:chemistry*; D002460:Cell Line; D003001:Cloning, Molecular; D004195:Disease Models, Animal; D005260:Female; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D051379:Mice; D020125:Mutation, Missense; D009474:Neurons / Q000821:virology; D011134:Polysaccharides / Q000032:analysis*; D011818:Rabies / Q000473:pathology* / Q000821:virology*; D011820:Rabies virus / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification / Q000472:pathogenicity*; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000737:chemistry*; D014774:Virulence; D014779:Virus Replication
D000956:Antigens, Viral; D006023:Glycoproteins; D011134:Polysaccharides; D014759:Viral Envelope Proteins; C064951:glycoprotein G, Rabies virus