A Single Amino Acid Substitution in the Viral Polymerase Creates a Temperature-Sensitive and Attenuated Recombinant Bovine Parainfluenza Virus Type 3

• Published in: Virology (New York, N.Y.) N.Y.), 2001-09, Vol.288 (2), p.342-350
• Main Authors: Haller, Aurelia A., MacPhail, Mia, Mitiku, Misrach, Tang, Roderick S.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino Acid Substitution; Animals; attenuation; Base Sequence; bovine parainfluenza type 3; Bovine parainfluenza virus 3; Cattle; Cercopithecus aethiops; Cricetinae; HeLa Cells; Humans; live virus vaccine vector; Mesocricetus; Molecular Sequence Data; Parainfluenza Virus 3, Bovine - enzymology; Parainfluenza Virus 3, Bovine - genetics; Parainfluenza Virus 3, Bovine - physiology; Parainfluenza Virus 3, Human - genetics; Parainfluenza Virus 3, Human - physiology; polymerase mutation; Recombination, Genetic; RNA Replicase - genetics; RNA Replicase - metabolism; RNA-Directed DNA Polymerase - genetics; RNA-Directed DNA Polymerase - metabolism; Temperature; temperature sensitivity; Vero Cells; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.2001.1106

Bovine parainfluenza virus type 3 (bPIV3) is under development as a live virus vaccine vector. The RNA genome of a recombinant bPIV3 harbored four nucleotide changes, one of which resulted in a mutation of the viral polymerase (A. A. Haller et al., 2000, J. Virol. 74, 11626–11635). The contribution of this conservative amino acid substitution (I1103V) in the polymerase to the temperature-sensitive and attenuation phenotypes of r-bPIV3 was investigated by creating a new virus, r-bPIV3(I), that expressed the wild-type polymerase. r-bPIV3(I) was not temperature-sensitive for growth in vitro and the replication of r-bPIV3(I) was no longer restricted in hamsters. The effect of the amino acid substitution in the polymerase was also studied in a chimeric bovine/human PIV3, a virus that displayed temperature-sensitive and attenuated phenotypes (A. A. Haller et al., 2000, J. Virol. 74, 11626–11635). It was not clear whether these defects were due to the impaired polymerase or the replacement of the bPIV3 surface glycoproteins with those of hPIV3. The results showed that the altered polymerase was indeed responsible for the temperature-sensitive phenotype of bovine/human PIV3 but did not appear to play a role in the attenuation phenotype.