Sequence analysis of enterovirus 71 3′UTR and construction of a recombinant cDNA infectious clone / 中华实验和临床病毒学杂志

ABSTRACT

Objective@#To sequence the 3′UTR of enterovirus 71 strains, investigate its foundation and impact in virulence by constructing a 3′UTR-replaced recombinant cDNA infectious clone.@*Methods@#Viral RNA of EV-A71 isolated viruses were extracted, and the nucleotide analysis was performed after sequencing. The 3′UTR of a full-length infectious clone of SDLY107 strain was replaced by its corresponding part of SDLY1 strain, and then the recombinant virus was constructed and identified.@*Results@#The nine isolated strains were classified into sub-genotype C4a of enterovirus (EV)-A71 by analysis, and nucleotide sequence homology for 3′UTR were 94%-100%. 3′UTR of EV-A71 strains may be associated with its pathogenicity. Identification of the rescued virus by sequencing and indirect immunofluorescence confirmed the successful construction of infectious recombinant virus.@*Conclusions@#Sequence analysis indicated that the 3′UTR may be involved in the pathogenicity of EV-A71. The recombinant virus SDLY107(1-3′UTR) was rescued successfully. Our study may provide evidence for further research on the influence of 3′UTR on the virulence of enterovirus 71.