In vivo fitness of respiratroy syncytial virus Palivizumab escape mutants
10.3760/cma.j.issn.0254-5101.2009.01.014
- VernacularTitle:呼吸道合胞病毒单克隆抗体逃逸株体内适合度研究
- Publication Type:Journal Article
- Keywords:
Respiratory syncytial virus;
Escape mutant;
Fitness;
Competitive replication;
Animal model
- From:
Chinese Journal of Microbiology and Immunology
2009;29(1):58-61
- CountryChina
- Language:Chinese
-
Abstract:
Objective To assess the fitness of the Palivizumab(PZ)-resistant respiratory syncytial virus(RSV) stain MP4 in cotton rat lung in vivo.Methods The mixture was made with equal amounts of A2 and MP4 virus and inoculated to immunosuppressed cotton rats which had been treated with cyclophosphamide.At day 4 and week 4 post inoculation.animals were sacrificed and lungs were harvested for virus titration by differential plaque assay and nucleotide sequence analysis.The F gene fragments were amplified by RT-PCR and cloned into the plasmid.then transformed E.coli.Certain amount of colonies were picked for same F gene fragment amplification,and PCR products were sequenced for A2 or MP4 signal at nucleotide 828.Relative amount of MP4 in the mixed viral population were then calculated.Results MP4 predomihated in cotton rat lungs either bv differential plaque assay or nucleotide sequence analysis at week 4 post inoculation,although the viral population consisted of more complicated viruses.Among the total 154analyzed F gene clones,the majority(120)contained MP4 gene signal.Conclusion The mutant MP4 virus iS of more fitness than parental A2 virus in cotton rat lungs.similar to that seen in vitro fitness assessment.Mutant viruses with similar resistance to PZ and increased fitness are more likely to disseminate in the population,particularly in immunocomprimised individuals.
