The 30-amino-acid deletion in the Nsp2 of highly pathogenic porcine reproductive and respiratory syndrome virus emerging in China is not related to its virulence.
During the past 2 years, an atypical clinical outbreak, caused by a highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) with a unique 30-amino-acid deletion in its Nsp2-coding region, was pandemic in China. In this study, we generated four full-length infectious cDNA clones: a clone of the highly virulent PRRSV strain JXwn06 (pWSK-JXwn), a clone of the low-virulence PRRSV strain HB-1/3.9 (pWSK-HB-1/3.9), a chimeric clone in which the Nsp2 region containing the 30-amino-acid deletion was replaced by the corresponding region of the low-virulence PRRSV strain HB-1/3.9 (pWSK-JXwn-HB1nsp2), and a mutated HB-1/3.9 clone with the same deletion in Nsp2 as JXwn06 (pWSK-HB1-ND30). We also investigated the pathogenicities of the rescued viruses (designated RvJXwn, RvJXwn-HB1nsp2, RvHB-1/3.9, and RvHB1-ND30, respectively) in specific-pathogen-free piglets in order to determine the role of the 30-amino-acid deletion in the virulence of the highly pathogenic PRRSV. All the rescued viruses could replicate stably in MARC-145 cells. Our findings indicated that RvJXwn-HB1nsp2 retained high virulence for piglets, like RvJXwn and the parental virus JXwn06, although the survival time of piglets infected with RvJXwn-HB1nsp2 was obviously prolonged. RvHB1-ND30 exhibited low virulence for piglets, like RvHB-1/3.9 and the parental virus HB-1/3.9. Therefore, we conclude that the 30-amino-acid deletion is not related to the virulence of the highly pathogenic PRRSV emerging in China.
Zhou
Lei
L
Key Laboratory of Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Zhang
Jialong
J
Zeng
Jingwen
J
Yin
Shuoyan
S
Li
Yanhua
Y
Zheng
Linying
L
Guo
Xin
X
Ge
Xinna
X
Yang
Hanchun
H
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002681:China; D018076:DNA, Complementary / Q000235:genetics; D016679:Genome, Viral; D008969:Molecular Sequence Data; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D012367:RNA, Viral / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion; D034421:Sus scrofa / Q000821:virology; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014774:Virulence; D014779:Virus Replication
D018076:DNA, Complementary; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins