A highly pathogenic porcine reproductive and respiratory syndrome virus generated from an infectious cDNA clone retains the in vivo virulence and transmissibility properties of the parental virus

ABSTRACT 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.

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Molecular Characterization of Transcriptome-wide Interactions between Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and Porcine Alveolar Macrophages in vivo

International Journal of Biological Sciences ◽

10.7150/ijbs.7.947 ◽

2011 ◽

Vol 7 (7) ◽

pp. 947-959 ◽

Cited By ~ 50

Author(s):

Ping Zhou ◽

Shanli Zhai ◽

Xiang Zhou ◽

Ping Lin ◽

Tengfei Jiang ◽

...

Keyword(s):

Molecular Characterization ◽

Alveolar Macrophages ◽

Respiratory Syndrome Virus ◽

Highly Pathogenic

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Evaluation of the Efficacy of an Attenuated Live Vaccine against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus in Young Pigs

Clinical and Vaccine Immunology ◽

10.1128/cvi.05646-11 ◽

2012 ◽

Vol 19 (8) ◽

pp. 1199-1206 ◽

Cited By ~ 45

Author(s):

Xue Leng ◽

Zhenguang Li ◽

Mingqi Xia ◽

Yanliang He ◽

Hua Wu

Keyword(s):

Respiratory Syndrome Virus ◽

Effective Protection ◽

Lethal Challenge ◽

Highly Pathogenic ◽

Live Virus ◽

Pork Industry ◽

Live Virus Vaccine ◽

Young Pigs ◽

Prrsv Strain

ABSTRACTHighly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever and high mortality in pigs of all ages and has severely affected the pork industry of China in the last few years. An attenuated HP-PRRSV strain, TJM, was obtained by passaging HP-PRRSV strain TJ on MARC-145 cells for 92 passages. Porcine reproductive and respiratory syndrome virus (PRRSV)- and antibody-free pigs were inoculated intramuscularly with TJM (105.050% tissue culture infective doses [TCID50]) and challenged at 28, 60, 120, and 180 days postimmunization (dpi). The results showed that 5/5, 5/5, 5/5, and 4/5 immunized pigs were protected from the lethal challenge and did not develop fever and clinical diseases at each challenge, respectively. Compared to control pigs, vaccinated pigs showed much milder pathological lesions and gained significantly more weight (P< 0.01). Sequence analysis of different passages of strain TJ showed that the attenuation resulted in a deletion of a continuous 120 amino acids (aa), in addition to the discontinuous 30-aa deletion in the nsp2 region. The analysis also demonstrated that the 120-aa deletion was genetically stablein vivo. These results suggested that HP-PRRSV TJM was efficacious against a lethal challenge with a virulent HP-PRRSV strain, and effective protection could last at least 4 months. Therefore, strain TJM is a good candidate for an efficacious modified live virus vaccine as well as a useful molecular marker vaccine against HP-PRRSV.

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A strain of highly pathogenic porcine reproductive and respiratory syndrome virus: genomic characterization, pathogenicity, and construction of an infectious full-length cDNA clone

Archives of Virology ◽

10.1007/s00705-021-05212-w ◽

2021 ◽

Author(s):

Shuangyun Wang ◽

Yanling Liu ◽

Linyang Yu ◽

Tairun Liang ◽

Pengfei Zhang ◽

...

Keyword(s):

Cdna Clone ◽

Full Length ◽

Respiratory Syndrome Virus ◽

Highly Pathogenic ◽

Full Length Cdna ◽

Genomic Characterization

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USE OF AN IN VIVO INFECTIOUS CDNA CLONE OF STRAWBERRY MILD YELLOW EDGE POTEXVIRUS TO STUDY THE ETIOLOGY OF THE DISEASE

Acta Horticulturae ◽

10.17660/actahortic.1998.471.5 ◽

1998 ◽

pp. 45-48 ◽

Cited By ~ 1

Author(s):

S. Lamprecht ◽

W. Jelkmann

Keyword(s):

Cdna Clone ◽

Infectious Cdna Clone

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Efficacy of a live attenuated highly pathogenic PRRSV vaccine against a NADC30-like strain challenge: implications for ADE of PRRSV

BMC Veterinary Research ◽

10.1186/s12917-021-02957-z ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Xin-xin Chen ◽

Xinyu Zhou ◽

Tengda Guo ◽

Songlin Qiao ◽

Zhenhua Guo ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Molecular Mechanisms ◽

Clinical Signs ◽

Bodyweight Gain ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Experimental Conditions ◽

Highly Pathogenic ◽

Highly Pathogenic Prrsv

Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV) infection can cause severe reproductive failure in sows and respiratory distress in pigs of all ages, leading to major economic losses. To date, there are still no effective strategies to prevent and control PRRSV. Antibody-dependent enhancement (ADE), a phenomenon in which preexisting non-neutralizing antibodies or sub-neutralizing antibodies facilitate virus entry and replication, may be a significant obstacle in the development of effective vaccines for many viruses, including PRRSV. However, the contribution of ADE to PRRSV infection remains controversial, especially in vivo. Whether attenuated PRRSV vaccines prevent or worsen subsequent disease in pigs infected by novel PRRSV strains requires more research. In the present study, in vivo experiments were conducted to evaluate ADE under different immune statuses, which were produced by waiting different lengths of time after vaccination with a commercially available attenuated highly pathogenic PRRSV (HP-PRRSV) vaccine (JXA1-R) before challenging the pigs with a novel heterologous NADC30-like strain. Results Piglets that were vaccinated before being challenged with PRRSV exhibited lower mortality rates, lower body temperatures, higher bodyweight gain, and lower viremia. These results demonstrate that vaccination with JXA1-R alleviated the clinical signs of PRRSV infection in all vaccinated groups. Conclusions The obtained data indicate that the attenuated vaccine test here provided partial protection against the NADC30-like strain HNhx. No signs of enhanced PRRSV infection were observed under the applied experimental conditions. Our results provide some insight into the molecular mechanisms underlying vaccine-induced protection or enhancement in PRRSV.

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