Mapping of mutations contributing to the temperature sensitivity of the Sabin 1 vaccine strain of poliovirus.
The temperature-sensitive and attenuated phenotypes of the Sabin type 1 vaccine strain of poliovirus result from numerous point mutations which occurred in the virulent Mahoney virus parent. One of these mutations is located in a 3D polymerase (3Dpol) codon (U-6203-->C, Tyr-73-->His) and is involved in attenuation in common mice (M. Tardy-Panit, B. Blondel, A. Martin, F. Tekaia, F. Horaud, and F. Delpeyroux, J. Virol. 67:4630-4638, 1993). This mutation also appears to contribute to temperature sensitivity, in association with at least 1 other of the 10 mutations of the 3'-terminal part of the genome including the 3Dpol coding and 3' noncoding regions. To map the other mutation(s), we constructed poliovirus mutants by mutagenesis and recombination of Mahoney and Sabin 1 cDNAs. Characterization of these poliovirus mutants showed that a second mutation in a 3Dpol codon (C-7071-->U, Thr-362-->Ile) contributes to temperature sensitivity. A mutation in the 3' noncoding region of the genome (A-7441-->G), alone or linked to another mutation (U-7410-->C), also appeared to be involved in this phenotype. The temperature-sensitive effect associated with the 3'-terminal part of the Sabin 1 genome results from the cumulative and/or synergistic effects of at least three genetic determinants, i.e., the His-73 and Ile-362 codons of 3Dpol and nucleotide G-7441. Sequence analysis of strains isolated from patients with vaccine-associated paralytic poliomyelitis showed that these genetic determinants are selected against in vivo, although the Ile-362 codon appeared to be more stable than either the His-73 codon or G-7441. These genetic determinants may contribute to the safety of Sabin 1 in vaccines.
Georgescu
M M
MM
Laboratoire d'Epidémiologie Moléculaire des Entérovirus, Institut Pasteur, Paris, France.
Tardy-Panit
M
M
Guillot
S
S
Crainic
R
R
Delpeyroux
F
F
D000818:Animals; D002522:Chlorocebus aethiops; D003062:Codon; D015684:Gene Products, pol / Q000096:biosynthesis / Q000235:genetics; D015751:Genes, pol; D016679:Genome, Viral; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010641:Phenotype; D010957:Plasmids; D017354:Point Mutation; D017955:Poliovirus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D011055:Poliovirus Vaccine, Oral; D013696:Temperature; D014162:Transfection; D014709:Vero Cells; D010948:Viral Plaque Assay; D014774:Virulence
D003062:Codon; D015684:Gene Products, pol; D011055:Poliovirus Vaccine, Oral