Genetic factors associated with loss of the temperature-sensitive phenotype of the influenza A/Alaska/77-ts-1A2 recombinant during growth in vivo

Tolpin, Mark D.; Massicot, Judith G.; Mullinix, Mary G.; Kim, Hyun Wha; Parrott, Robert H.; Chanock, Robert M.; Murphy, Brian R.

doi:10.1016/0042-6822(81)90298-1

Cited by 58 publications

(34 citation statements)

References 37 publications

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“…(33,35). Since molecular engineering makes it possible to alter codons that specify the ts and att phenotypes, we sought in the present study to examine whether the choice of alternative codons at a given locus can be used to enhance the genetic stability of a ts-att mutation and to augment the level of attenuation.…”

Section: Discussionmentioning

confidence: 99%

“…The high mutation rate for RNA viruses in general would make single-nucleotide changes susceptible to genetic and phenotypic instability. For example, respiratory viruses bearing two or more ts mutations demonstrated the tendency to lose their phenotype following replication in vivo (22,33,35). This finding suggests that it would be desirable to make an effort early in the development of a HPIV1 live-attenuated virus vaccine to increase the genetic stability of individual mutations that are to be included in the vaccine.…”

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confidence: 98%

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Codon Substitution Mutations at Two Positions in the L Polymerase Protein of Human Parainfluenza Virus Type 1 Yield Viruses with a Spectrum of Attenuation In Vivo and Increased Phenotypic Stability In Vitro

McAuliffe

Surman

Newman

et al. 2004

J Virol

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The Y942H and L992F temperature-sensitive (ts) and attenuating amino acid substitution mutations, previously identified in the L polymerase of the HPIV3cp45 vaccine candidate, were introduced into homologous positions of the L polymerase of recombinant human parainfluenza virus type 1 (rHPIV1). In rHPIV1, the Y942H mutation specified the ts phenotype in vitro and the attenuation (att) phenotype in hamsters, whereas the L992F mutation specified neither phenotype. Each of these codon mutations was generated by a single nucleotide substitution and therefore had the potential to readily revert to a codon specifying the wild-type amino acid residue. We introduced alternative amino acid assignments at codon 942 or 992 as a strategy to increase genetic stability and to generate mutants that exhibit a range of attenuation. Twenty-three recombinants with codon substitutions at position 942 or 992 of the L protein were viable. One highly ts and att mutant, the Y942A virus, which had a difference of three nucleotides from the codon encoding a wild-type tyrosine, also possessed a high level of genetic and phenotypic stability upon serial passage in vitro at restrictive temperatures compared to that of the parent Y942H virus, which possessed a single nucleotide substitution. We obtained mutants with substitutions at position 992 that, in contrast to the L992F virus, possessed the ts and att phenotypes. These findings identify the use of alternative codon substitution mutations as a method that can be used to generate candidate vaccine viruses with increased genetic stability and/or a modified level of attenuation.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 98%

Codon Substitution Mutations at Two Positions in the L Polymerase Protein of Human Parainfluenza Virus Type 1 Yield Viruses with a Spectrum of Attenuation In Vivo and Increased Phenotypic Stability In Vitro

McAuliffe

Surman

Newman

et al. 2004

J Virol

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“…Previous experiments with reovirus or influenza virus ts mutants (Ramig & Fields, 1979;Tolpin et al, 1981) have shown that appearance of ts revertants may be due to extragenic suppression caused by an additional mutation in some other gene.…”

Section: Analysis Of a Ts Phenotype Of Clones Obtained By Back-crossimentioning

confidence: 99%

“…The difference in titre at 36 °C and 42 °C of the ts segregants was about 102, which is significantly lower than in the initial mutants. However, in experiments with reovirus (Ramig & Fields, 1979) and influenza virus (Tolpin et al, 1981), analyses of extragenic suppression revealed ts segregants in which differences in titres at optimal and non-permissive temperatures were less significant than in the initial ts mutants.…”

Section: Determination Of the Gene Of Fpv Weybridge Suppressing A Ts mentioning

confidence: 99%

“…Recently, it has been shown (Tolpin et al, 1981) that a mutation in the P2 gene of a human influenza virus can suppress the expression of a ts phenotype of the P3 gene and that mutations in segment 8 of fowl plague virus Rostock can be suppressed by replacement with segments 1 or 2 of another influenza A virus strain (Scholtissek & Spring, 1981).…”

Section: Introductionmentioning

confidence: 99%

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