Attenuation of mouse hepatitis virus by deletion of the LLRKxGxKG region of Nsp1.

Attenuation of mouse hepatitis virus by deletion of the LLRKxGxKG region of Nsp1.

Lin Lei, SUN Ying, Luo Baojun, Yang Yi, He Xiang, Su-Wen Li, Sun Zounan, Guo Deyin, Zhuqing Yu, Liu Jingmei, Chang Guohui

Coronaviruses are a family of large positive-sense RNA viruses that are responsible for a wide range of important veterinary and human diseases. Nsp1 has been shown to have an important role in the pathogenetic mechanisms of coronaviruses in vivo. To assess the function of a relatively conserved domain (LLRKxGxKG) of MHV nsp1, a mutant virus, MHV-nsp1-27D, with a 27 nts (LLRKxGxKG) deletion in nsp1, was constructed using a reverse genetic system with a vaccinia virus vector. The mutant virus had similar growth kinetics to MHV-A59 wild-type virus in 17CI-1 cells, but was highly attenuated in vivo. Moreover, the mutant virus completely protected C57BL/6 mice from a lethal MHV-A59 challenge. To further analyze the mechanism of the attenuation of the mutant virus, changes in reporter gene expression were measured in nsp1- or nsp1-27D-expressing cells; the results showed that nsp1 inhibited reporter gene expression controlled by different promoters, but that this inhibition was reduced for nsp1-27D. The research in vivo and in vitro suggests that the LLRKxGxKG region of nsp1 may play an important role in this process.

2013

DOI: 10.1371/journal.pone.0061166

PLoS ONE

Public Library of Science (PLoS)

Science, Medicine

EN