scholarly journals Porcine Reproductive and Respiratory Syndrome Virus Antagonizes PCSK9’s Antiviral Effect via Nsp11 Endoribonuclease Activity

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 655
Author(s):  
Yujiao Zhang ◽  
Fei Gao ◽  
Liwei Li ◽  
Kuan Zhao ◽  
Shan Jiang ◽  
...  

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the swine industry worldwide. Our previous study had indicated that proprotein convertase subtilisin/kexin type 9 (PCSK9) was a responsive gene in porcine alveolar macrophages (PAMs) upon PRRSV infection. However, whether PCSK9 impacts the PRRSV replication and how the PRRSV modulates host PCSK9 remains elusive. Here, we demonstrated that PCSK9 protein suppressed the replication of both type-1 and type-2 PRRSV species. More specifically, the C-terminal domain of PCSK9 was responsible for the antiviral activity. Besides, we showed that PCSK9 inhibited PRRSV replication by targeting the virus receptor CD163 for degradation through the lysosome. In turn, PRRSV could down-regulate the expression of PCSK9 in both PAMs and MARC-145 cells. By screening the nonstructural proteins (nsps) of PRRSV, we showed that nsp11 could antagonize PCSK9’s antiviral activity. Furthermore, mutagenic analyses of PRRSV nsp11 revealed that the endoribonuclease activity of nsp11 was critical for antagonizing the antiviral effect of PCSK9. Collectively, our data provide further insights into the interaction between PRRSV and the cell host and offer a new potential target for the antiviral therapy of PRRSV.

2016 ◽  
Vol 91 (2) ◽  
Author(s):  
Kevin D. Wells ◽  
Rachel Bardot ◽  
Kristin M. Whitworth ◽  
Benjamin R. Trible ◽  
Ying Fang ◽  
...  

ABSTRACT CD163 knockout (KO) pigs are resistant to infection with genotype 2 (type 2) porcine reproductive and respiratory syndrome virus (PRRSV). Furthermore, the substitution of CD163 scavenger receptor cysteine-rich (SRCR) domain 5 with a homolog of human CD163-like (hCD163L1) SRCR 8 domain confers resistance of transfected HEK cells to type 1 PRRSV. As a means to understand the role of domain 5 in PRRSV infection with both type 1 and type 2 viruses, pigs were genetically modified (GM) to possess one of the following genotypes: complete knockout (KO) of CD163, deletions within SRCR domain 5, or replacement (domain swap) of SRCR domain 5 with a synthesized exon encoding a homolog of hCD163L1 SRCR domain 8. Immunophenotyping of porcine alveolar macrophages (PAMs) showed that pigs with the KO or SRCR domain 5 deletion did not express CD163. When placed in culture, PAMs from pigs with the CD163 KO phenotype were completely resistant to a panel consisting of six type 1 and nine type 2 isolates. PAMs from pigs that possessed the hCD163L1 domain 8 homolog expressed CD163 and supported the replication of all type 2 isolates, but no type 1 viruses. Infection of CD163-modified pigs with representative type 1 and type 2 viruses confirmed the in vitro results. The results confirm that CD163 is the likely receptor for all PRRS viruses. Even though type 1 and type 2 viruses are considered phenotypically similar at several levels, there is a distinct difference between the viral genotypes in the recognition of CD163. IMPORTANCE Genetic modification of the CD163 gene creates the opportunity to develop production animals that are resistant to PRRS, the costliest viral disease to ever face the swine industry. The results create further opportunities to develop refinements in the modification of CD163 with the goal of making pigs refractory to infection while retaining important CD163 functions.


2021 ◽  
Author(s):  
Jing Chen ◽  
Shijie Zhao ◽  
Zhiying Cui ◽  
Wen Li ◽  
Pengli Xu ◽  
...  

Porcine reproductive and respiratory syndrome virus is a major economically significant pathogen and has evolved several strategies to evade host's antiviral response and provide favorable conditions for survival. In the present study, we demonstrated that a host microRNA, miR-376b-3p, was upregulated by PRRSV infection through the viral components, nsp4 and nsp11, and miR-376b-3p can directly target tripartite motif-containing 22 (TRIM22) to impair its anti-PRRSV activity, thus facilitating the replication of PRRSV. Meanwhile, we found that TRIM22 induced degradation of the nucleocapsid protein (N) of PRRSV by interacting with N protein to inhibit PRRSV replication, and further study indicated that TRIM22 could enhance the activation of lysosomal pathway by interacting with LC3 to induce lysosomal degradation of N protein. In conclusion, PRRSV increased miR-376b-3p expression and hijacked the host miR-376b-3p to promote PRRSV replication by impairing the antiviral effect of TRIM22. Therefore, our finding outlines a novel strategy of immune evasion exerted by PRRSV, which is helpful for better understanding the pathogenesis of PRRSV. IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes enormous economic losses each year in the swine industry worldwide. MicroRNAs (miRNAs) play important roles during viral infections via modulating the expression of viral or host genes at post-transcriptional level. TRIM22 has recently been identified as a key restriction factor that inhibited the replication of a number of human virus such as HIV, ECMV, HCV, HBV, IAV, and RSV. Here we showed that host miR-376b-3p could be up-regulated by PRRSV and functioned to impair the anti-PRRSV role of TRIM22 to facilitate PRRSV replication. Meanwhile, we found that TRIM22 inhibited the replication of PRRSV by interacting with viral N protein and accelerating its degradation through the lysosomal pathway. Collectively, the paper described a novel mechanism that PRRSV exploited the host miR-376b-3p to evade antiviral responses and provided a new insight into the study of virus-host interactions.


2019 ◽  
Author(s):  
huawei li ◽  
ruining wang ◽  
wenjia wang ◽  
yinfeng kang ◽  
mengmeng zhao

Abstract Background : Porcine reproductive and respiratory syndrome virus (PRRSV) is a serious pathogen that causes $664 million losses per year to the swine industry. There are few useful vaccines that can provide protection against PRRSV infection. 2′, 5′-oligoadenylate synthetase-like protein (OASL) has antiviral activity, this has not been shown for PRRSV and the mechanism is unknown. Methods : Expression of OASL in porcine alveolar macrophages induced by interferon (IFN)-b stimulation and PRRSV infection was examined by real-time polymerase chain reaction. Exogenous expression and knockdown of OASL were used to determine the role of OASL in the PRRSV replication cycle. The type I IFN signaling pathway was evaluated after OASL overexpression. Results : In this study, we found that the expression of OASL in porcine alveolar macrophages was significantly increased by IFN-b stimulation and PRRSV infection. Porcine-OASL-specific small interfering RNA (siRNA) promoted PRRSV replication, whereas exogenous expression of porcine OASL inhibited replication of the virus. The anti-PRRSV activity of porcine OASL was lost after knockdown of retinoic acid-inducible gene I ( DDX58 , also known as RIG-I ). Conclusions : Porcine OASL suppresses PRRSV replication.


2000 ◽  
Vol 55 (9-10) ◽  
pp. 830-835 ◽  
Author(s):  
Julia Serkedjieva

Abstract The water extract from the red marine alga Polysiphonia denudata (Dillwyn) Kütz. from the Bulgarian Black Sea coast selectively inhibited the reproduction of herpes virus type 1 and type 2 in cell cultures (EC50 = 8.7 to 47.7 mg/ml) as shown by the reduction of virusinduced cytopathic effect and viral infectivity. The virus-inhibitory effect was dose-related, strain-specific and depended on virus inoculum. The inhibition affected adsorption as well as the intracellular stages of viral replication. The presence of the extract throughout the whole replicative cycle was necessary for the full expression of the antiviral effect. In higher concentrations (MIC90 = 6.5 mg/ml) the extract exhibited strong extracellular virus inactivating activity.


2014 ◽  
Vol 95 (11) ◽  
pp. 2486-2494 ◽  
Author(s):  
Changhoon Park ◽  
Hwi Won Seo ◽  
Su-Jin Park ◽  
Kiwon Han ◽  
Chanhee Chae

The objective of this study was to compare the virulence and pathogenicity of a combination of concurrent infections of two genotypes of porcine circovirus type 2 (PCV2) and two genotypes of porcine reproductive and respiratory syndrome virus (PRRSV) in terms of PCV2 viraemia, and PCV2-associated lesions and antigens in co-infected pigs. Pigs with PCV2a (or 2b)/type 1 (or type 2) PRRSV had significantly (P<0.05) higher mean clinical respiratory scores and lower average daily weight gain compared with pigs with PCV2a (or 2b). Co-infection induced significantly lower levels of anti-PCV2 and anti-PRRSV IgG antibodies than infection with one genotype alone, regardless of the genotype of the two viruses. Pigs with PCV2a (or 2b)/type 2 PRRSV had significantly (P<0.05) higher levels of PCV2 viraemia, more severe PCV2-associated lesions, and more PCV2 DNA within the lesions compared with pigs with PCV2a (or 2b)/type 1 PRRSV. However, there was no significant difference in these parameters in pigs with PCV2a/type 2 PRRSV or PCV2b/type 2 PRRSV. The results of this study demonstrate significant differences in the virulence and pathogenicity of type 1 and type 2 PRRSV but no significant differences in the virulence and pathogenicity of PCV2a and PCV2b with respect to the production of PCV2-associated lesions.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Jing Bi ◽  
Shuang Song ◽  
Liurong Fang ◽  
Dang Wang ◽  
Huiyuan Jing ◽  
...  

Porcine reproductive and respiratory syndrome virus (PRRSV) is anArterivirusthat has been devastating the swine industry worldwide since the late 1980s. Previous studies have reported that PRRSV infection induced the production of IL-1β. However, the cellular sensors and signaling pathways involved in this process have not been elucidated yet. Here, we studied the mechanisms responsible for the production of IL-1βin response to highly pathogenic PRRSV. Upon PRRSV infection of primary porcine alveolar macrophages, both mRNA expression and secretion of IL-1βwere significantly increased in a time- and dose-dependent manner. We also investigated the role of several pattern-recognition receptors and adaptor molecules in this response and showed that the TLR4/MyD88 pathway and its downstream signaling molecules, NF-κB, ERK1/2, and p38 MAPKs, were involved in IL-1βproduction during PRRSV infection. Treatment with specific inhibitors or siRNA knockdown assays demonstrated that components of the NLRP3 inflammasome were crucial for IL-1βsecretion but not for IL-1βmRNA expression. Furthermore, TLR4/MyD88/NF-κB signaling pathway was involved in PRRSV-induced expression of NLRP3 inflammasome components. Together, our results deciphered the pathways leading from recognition of PRRSV to the production and release of IL-1β, providing a deeper knowledge of the mechanisms of PRRSV-induced inflammation responses.


1992 ◽  
Vol 3 (2) ◽  
pp. 85-94 ◽  
Author(s):  
D. Sutton ◽  
J. Taylor ◽  
T. H. Bacon ◽  
M. R. Boyd

Combinations of penciclovir (PCV) with other antiviral agents (acyclovir, ACV; ganciclovir, GCV; foscarnet, PFA; azido-thymidine, AZT) or with human interferons (HulFN-α,β,γ) were tested for inhibitory activity against herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2) in cell culture. The antiviral interactions observed between combinations of PCV with ACV or GCV were purely additive. Combinations of PCV with HulFNs demonstrated highly synergistic anti-herpesvirus activity; some synergy was also detected between PCV and PFA against HSV-1. High concentrations of AZT inhibited the antiviral activity of PCV; this antagonism was competitive. In more detailed studies it was demonstrated that high concentrations of AZT also inhibited the antiviral activity of ACV, and that ACV was more sensitive to this antagonism than PCV. It was concluded that the antagonism was unlikely to have clinical significance.


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