title: Sendai virus intra-host population dynamics and host immunocompetence influence viral virulence duringin vivopassage.
abstract: In vivoserial passage of non-pathogenic viruses has been shown to lead to increased viral virulence, and although the precise mechanism(s) are not clear, it is known that both host and viral factors are associated with increased pathogenicity. Under- or overnutrition leads to a decreased or dysregulated immune response and can increase viral mutant spectrum diversity and virulence. The objective of this study was to identify the role of viral mutant spectra dynamics and host immunocompetence in the development of pathogenicity duringin vivopassage. Because the nutritional status of the host has been shown to affect the development of viral virulence, the diet of animal model reflected two extremes of diets which exist in the global population, malnutrition and obesity. Sendai virus was serially passaged in groups of mice with differing nutritional status followed by transmission of the passaged virus to a second host species, guinea pigs. Viral population dynamics were characterized using deep sequence analysis and computational modeling. Histopathology, viral titer and cytokine assays were used to characterize viral virulence. Viral virulence increased with passage and the virulent phenotype persisted upon passage to a second host species. Additionally, nutritional status of mice during passage influenced the phenotype. Sequencing revealed the presence of several non-synonymous changes in the consensus sequence associated with passage, a majority of which occurred in the hemagglutinin-neuraminidase and polymerase genes, as well as the presence of persistent high frequency variants in the viral population. In particular, an N1124D change in the consensus sequences of the polymerase gene was detected by passage 10 in a majority of the animals.In vivocomparison of an 1124D plaque isolate to a clone with 1124N genotype indicated that 1124D was associated with increased virulence.
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: José
authors: J
authors: Peña
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Haiyin
authors: H
authors: Chen-Harris
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Jonathan E
authors: JE
authors: Allen
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Mona
authors: M
authors: Hwang
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Maher
authors: M
authors: Elsheikh
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Shalini
authors: S
authors: Mabery
authors: Australian Infectious Diseases Research Centre, University of Queensland , Brisbane, Australia; and.
authors: Helle
authors: H
authors: Bielefeldt-Ohmann
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Adam T
authors: AT
authors: Zemla
authors: Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors: Richard A
authors: RA
authors: Bowen
authors: Lawrence Livermore National Laboratory, Livermore, CA, USA.
authors: Monica K
authors: MK
authors: Borucki