scholarly journals Molecular serotyping ofHaemophilus parasuisisolated from diseased pigs and the relationship between serovars and pathological patterns in Taiwan

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6017 ◽  
Author(s):  
Wei-Hao Lin ◽  
Hsing-Chun Shih ◽  
Chuen-Fu Lin ◽  
Cheng-Yao Yang ◽  
Yung-Fu Chang ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Vaccination Programs ◽  
Polysaccharide Biosynthesis ◽  
Molecular Serotyping ◽  
Glässer’S Disease ◽  
Glasser's Disease ◽  
The Relationship

BackgroundHaemophilus parasuisis the etiological agent of Glässer’s disease, and causes severe economic losses in the swine industry. Serovar classification is intended as an indicator of virulence and pathotype and is also crucial for vaccination programs and vaccine development. According to a polysaccharide biosynthesis locus analysis,H. parasuisisolates could be classified by a molecular serotyping assay except serovars 5 and 12 detected by the same primer pair. The aim of this study was to identifyH. parasuisisolates from diseased pigs in Taiwan by using a molecular serotyping assay and to analyze the relationship between serovars and pathological patterns.MethodsFrom August 2013 to February 2017, a total of 133 isolates from 277 lesions on 155 diseased animals from 124 infected herds serotyped by multiplex PCR and analyzed with pathological data.ResultsThe dominant serovars ofH. parasuisin Taiwan were serovars 5/12 (37.6%), 4 (27.8%) and 13 (15%) followed by molecular serotyping non-typable (MSNT) isolates (13.5%). Nevertheless, the serovar-specific amplicons were not precisely the same sizes as previously indicated in the original publication, and MSNT isolates appeared with unexpected amplicons or lacked serovar-specific amplicons. MostH. parasuisisolates were isolated from nursery pigs infected with porcine reproductive and respiratory syndrome virus. The percentage of lung lesions (30.4%) showingH. parasuisinfection was significantly higher than that of serosal lesions.DiscussionCollectively, the distribution of serovars in Taiwan is similar to that found in other countries, but MSNT isolates remain due to genetic variations. Furthermore, pulmonary lesions may be optimum sites forH. parasuisisolation, the diagnosis of Glässer’s disease, and may also serve as points of origin for systemicH. parasuisinfections in hosts.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus: Immune Escape and Application of Reverse Genetics in Attenuated Live Vaccine Development

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 480
Author(s):  
Honglei Wang ◽  
Yangyang Xu ◽  
Wenhai Feng
Keyword(s):  
Immune Responses ◽  
Reverse Genetics ◽  
Vaccine Development ◽  
Immune Escape ◽  
Rna Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Live Vaccines ◽  
Host Immune Responses ◽  
Inactivated Vaccines

Porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus widely prevalent in pigs, results in significant economic losses worldwide. PRRSV can escape from the host immune response in several processes. Vaccines, including modified live vaccines and inactivated vaccines, are the best available countermeasures against PRRSV infection. However, challenges still exist as the vaccines are not able to induce broad protection. The reason lies in several facts, mainly the variability of PRRSV and the complexity of the interaction between PRRSV and host immune responses, and overcoming these obstacles will require more exploration. Many novel strategies have been proposed to construct more effective vaccines against this evolving and smart virus. In this review, we will describe the mechanisms of how PRRSV induces weak and delayed immune responses, the current vaccines of PRRSV, and the strategies to develop modified live vaccines using reverse genetics systems.

scholarly journals The Function of the PRRSV–Host Interactions and Their Effects on Viral Replication and Propagation in Antiviral Strategies

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 364
Author(s):  
Jun Ma ◽  
Lulu Ma ◽  
Meiting Yang ◽  
Wei Wu ◽  
Wenhai Feng ◽  
...  
Keyword(s):  
Immune Response ◽  
Molecular Mechanisms ◽  
Immune Escape ◽  
Rna Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Live Virus ◽  
Virus Challenge ◽  
Host Interactions

Porcine reproductive and respiratory syndrome virus (PRRSV) affects the global swine industry and causes disastrous economic losses each year. The genome of PRRSV is an enveloped single-stranded positive-sense RNA of approximately 15 kb. The PRRSV replicates primarily in alveolar macrophages of pig lungs and lymphatic organs and causes reproductive problems in sows and respiratory symptoms in piglets. To date, studies on how PRRSV survives in the host, the host immune response against viral infections, and pathogenesis, have been reported. PRRSV vaccines have been developed, including inactive virus, modified live virus, attenuated live vaccine, DNA vaccine, and immune adjuvant vaccines. However, there are certain problems with the durability and effectiveness of the licensed vaccines. Moreover, the high variability and fast-evolving populations of this RNA virus challenge the design of PRRSV vaccines, and thus effective vaccines against PRRSV have not been developed successfully. As is well known, viruses interact with the host to escape the host’s immune response and then replicate and propagate in the host, which is the key to virus survival. Here, we review the complex network and the mechanism of PRRSV–host interactions in the processes of virus infection. It is critical to develop novel antiviral strategies against PRRSV by studying these host–virus interactions and structures to better understand the molecular mechanisms of PRRSV immune escape.

MicroRNA-376b-3p Promotes Porcine Reproductive and Respiratory Syndrome Virus Replication by Targeting Viral Restriction Factor TRIM22

2021 ◽  
Author(s):  
Jing Chen ◽  
Shijie Zhao ◽  
Zhiying Cui ◽  
Wen Li ◽  
Pengli Xu ◽  
...  
Keyword(s):  
Viral Infections ◽  
Antiviral Effect ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Restriction Factor ◽  
Transcriptional Level ◽  
Swine Industry ◽  
Human Virus ◽  
N Protein ◽  
Novel Strategy

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.

scholarly journals Integrated time-serial transcriptome networks reveal common innate and tissue-specific adaptive immune responses to PRRSV infection

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Byeonghwi Lim ◽  
Sangwook Kim ◽  
Kyu-Sang Lim ◽  
Chang-Gi Jeong ◽  
Seung-Chai Kim ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza A ◽  
Vaccine Development ◽  
Expression Patterns ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Specific Group ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Gene Expression Control

Abstract Porcine reproductive and respiratory syndrome virus (PRRSV) infection is the most important viral disease causing severe economic losses in the swine industry. However, mechanisms underlying gene expression control in immunity-responsible tissues at different time points during PRRSV infection are poorly understood. We constructed an integrated gene co-expression network and identified tissue- and time-dependent biological mechanisms of PRRSV infection through bioinformatics analysis using three tissues (lungs, bronchial lymph nodes [BLNs], and tonsils) via RNA-Seq. Three groups with specific expression patterns (i.e., the 3-dpi, lung, and BLN groups) were discovered. The 3 dpi-specific group showed antiviral and innate-immune signalling similar to the case for influenza A infection. Moreover, we observed adaptive immune responses in the lung-specific group based on various cytokines, while the BLN-specific group showed down-regulated AMPK signalling related to viral replication. Our study may provide comprehensive insights into PRRSV infection, as well as useful information for vaccine development.

scholarly journals Porcine Reproductive and Respiratory Syndrome Virus Activates Lipophagy To Facilitate Viral Replication through Downregulation of NDRG1 Expression

2019 ◽  
Vol 93 (17) ◽  
Author(s):  
Jiang Wang ◽  
Jiao-Yang Liu ◽  
Ke-Yu Shao ◽  
Ying-Qian Han ◽  
Guo-Li Li ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Virus Assembly ◽  
Rna Virus ◽  
Progeny Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Effective Strategies ◽  
Single Positive ◽  
Negative Role

ABSTRACTAutophagy maintains cellular homeostasis by degrading organelles, proteins, and lipids in lysosomes. Autophagy is involved in the innate and adaptive immune responses to a variety of pathogens. Some viruses can hijack host autophagy to enhance their replication. However, the role of autophagy in porcine reproductive and respiratory syndrome virus (PRRSV) infection is unclear. Here, we show that N-Myc downstream-regulated gene 1 (NDRG1) deficiency induced autophagy, which facilitated PRRSV replication by regulating lipid metabolism. NDRG1 mRNA is expressed ubiquitously in most porcine tissues and most strongly in white adipose tissue. PRRSV infection downregulated the expression of NDRG1 mRNA and protein, while NDRG1 deficiency contributed to PRRSV RNA replication and progeny virus assembly. NDRG1 deficiency reduced the number of intracellular lipid droplets (LDs), but the expression levels of key genes in lipogenesis and lipolysis were not altered. Our results also show that NDRG1 deficiency promoted autophagy and increased the subsequent yields of hydrolyzed free fatty acids (FFAs). The reduced LD numbers, increased FFA levels, and enhanced PRRSV replication were abrogated in the presence of an autophagy inhibitor. Overall, our findings suggest that NDRG1 plays a negative role in PRRSV replication by suppressing autophagy and LD degradation.IMPORTANCEPorcine reproductive and respiratory syndrome virus (PRRSV), an enveloped single-positive-stranded RNA virus, causes acute respiratory distress in piglets and reproductive failure in sows. It has led to tremendous economic losses in the swine industry worldwide since it was first documented in the late 1980s. Vaccination is currently the major strategy used to control the disease. However, conventional vaccines and other strategies do not provide satisfactory or sustainable prevention. Therefore, safe and effective strategies to control PRRSV are urgently required. The significance of our research is that we demonstrate a previously unreported relationship between PRRSV, NDRG1, and lipophagy in the context of viral infection. Furthermore, our data point to a new role for NDRG1 in autophagy and lipid metabolism. Thus, NDRG1 and lipophagy will have significant implications for understanding PRRSV pathogenesis for developing new therapeutics.

scholarly journals Genomic Analysis of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Circulating in Pig Farms in West China

2018 ◽  
Vol 6 (27) ◽  
Author(s):  
Chenyu Zhang ◽  
Hu Shan ◽  
Jianxin Wen
Keyword(s):  
Genomic Analysis ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Highly Pathogenic ◽  
West China ◽  
Pig Farms ◽  
Long Time

Porcine reproductive and respiratory syndrome virus (PRRSV), which leads to tremendous economic losses worldwide, is currently one of the most threatening viruses for the swine industry. However, PRRSV outbreaks in West China are rarely reported, even though the virus has remained active for a long time across the country.

scholarly journals Detection of Haemophilus parasuis isolates from South China by loop-mediated isothermal amplification and isolate characterisation

2012 ◽  
Vol 79 (1) ◽  
Author(s):  
Jian-min Zhang ◽  
Hai-yan Shen ◽  
Ming Liao ◽  
Tao Ren ◽  
Li-li Guo ◽  
...  
Keyword(s):  
16S Rrna ◽  
South China ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Economic Losses ◽  
Lamp Method ◽  
Haemophilus Parasuis ◽  
Loop Mediated Isothermal Amplification ◽  
Glässer’S Disease ◽  
Glasser's Disease

Haemophilus parasuis is the etiological agent of Glässer’s disease, which is characterised by fibrinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. In this study, a loop-mediated isothermal amplification (LAMP) test was developed to improve the specificity, facility and speed of diagnosis of H. parasuis isolates. The LAMP assay rapidly amplified the target gene within 50 min incubation at 63 °C in a laboratory water bath. The LAMP amplicon could be visualised directly in the reaction tubes following the addition of SYBR Green I dye. The detection limit of this LAMP method was 10 CFU/mL, which was 10 times more sensitive than the earlier 16S rRNA polymerase chain reaction (PCR) test conducted by Oliveira, Galina and Pijoan (2001), and no cross-reactivity was observed from other non-H. parasuis strains. This LAMP test was evaluated further on 187 clinical specimens from pigs suspected of being infected with H. parasuis. Forty-three were found positive by bacterial isolation of H. parasuis, as well as by the 16S rRNA PCR and LAMP tests. The 43 H. parasuis isolates were classified into 9 serovars and had 37 genetic patterns when analysed by pulsed-field gel electrophoresis (PFGE). This displayed that various H. parasuis serovars and genotypes were widely distributed in South China. Therefore, the speed, specificity and sensitivity of the LAMP test, the lack of a need for expensive equipment, and the visual readout showed great potential for a correct clinical diagnosis of H. parasuis in favour of controlling Glässer’s disease.

scholarly journals Xanthohumol inhibits PRRSV proliferation and alleviates oxidative stress induced by PRRSV via the Nrf2–HMOX1 axis

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Xuewei Liu ◽  
Zhongbao Song ◽  
Juan Bai ◽  
Hans Nauwynck ◽  
Yongxiang Zhao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Therapeutic Strategy ◽  
Antioxidant Response ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Related Factor ◽  
Nuclear Factor ◽  
Swine Industry ◽  
Therapeutic Drugs ◽  
Swine Pathogen

Abstract Porcine reproductive and respiratory syndrome virus (PRRSV) is a prevalent and endemic swine pathogen that causes significant economic losses in the global swine industry. Commercial vaccines provide limited protection against this virus, and no highly effective therapeutic drugs are yet available. In this study, we first screened a library of 386 natural products and found that xanthohumol (Xn), a prenylated flavonoid found in hops, displayed high anti-PRRSV activity by inhibiting PRRSV adsorption onto and internalization into cells. Transcriptome sequencing revealed that Xn treatment stimulates genes associated with the antioxidant response in the nuclear factor-erythroid 2-related factor 2 (Nrf2) signalling pathway. Xn causes increased expression of Nrf2, HMOX1, GCLC, GCLM, and NQO1 in Marc-145 cells. The action of Xn against PRRSV proliferation depends on Nrf2 in Marc-145 cells and porcine alveolar macrophages (PAMs). This finding suggests that Xn significantly inhibits PRRSV proliferation and decreases viral-induced oxidative stress by activating the Nrf2–HMOX1 pathway. This information should be helpful for developing a novel prophylactic and therapeutic strategy against PRRSV infection.

scholarly journals Helicase of Type 2 Porcine Reproductive and Respiratory Syndrome Virus Strain HV Reveals a Unique Structure

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 215 ◽  
Author(s):  
Chenjun Tang ◽  
Zengqin Deng ◽  
Xiaorong Li ◽  
Meiting Yang ◽  
Zizi Tian ◽  
...  
Keyword(s):  
Nonstructural Protein ◽  
Equine Arteritis Virus ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Multiple Processes ◽  
Multiple Domains ◽  
Functional Analyses ◽  
Zinc Binding Domain

Porcine reproductive and respiratory syndrome virus (PRRSV) is prevalent throughout the world and has caused great economic losses to the swine industry. Nonstructural protein 10 (nsp10) is a superfamily 1 helicase participating in multiple processes of virus replication and one of the three most conserved proteins in nidoviruses. Here we report three high resolution crystal structures of highly pathogenic PRRSV nsp10. PRRSV nsp10 has multiple domains, including an N-terminal zinc-binding domain (ZBD), a β-barrel domain, a helicase core with two RecA-like domains, and a C-terminal domain (CTD). The CTD adopts a novel fold and is required for the overall structure and enzymatic activities. Although each domain except the CTD aligns well with its homologs, PRRSV nsp10 adopts an unexpected extended overall structure in crystals and solution. Moreover, structural and functional analyses of PRRSV nsp10 versus its closest homolog, equine arteritis virus nsp10, suggest that DNA binding might induce a profound conformational change of PRRSV nsp10 to exert functions, thus shedding light on the mechanisms of activity regulation of this helicase.

scholarly journals Challenges for Porcine Reproductive and Respiratory Syndrome (PRRS) Vaccine Design: Reviewing Virus Glycoprotein Interactions with CD163 and Targets of Virus Neutralization

2019 ◽  
Vol 6 (1) ◽  
pp. 9 ◽  
Author(s):  
Ana Stoian ◽  
Raymond Rowland
Keyword(s):  
Vaccine Development ◽  
Noncovalent Interactions ◽  
Rna Virus ◽  
Neutralizing Antibody ◽  
Complex Surface ◽  
Surface Proteins ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Live Virus ◽  
Potential Vaccine

One of the main participants associated with the onset and maintenance of the porcine respiratory disease complex (PRDC) syndrome is porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus that has plagued the swine industry for 30 years. The development of effective PRRS vaccines, which deviate from live virus designs, would be an important step towards the control of PRRS. Potential vaccine antigens are found in the five surface proteins of the virus, which form covalent and multiple noncovalent interactions and possess hypervariable epitopes. Consequences of this complex surface structure include antigenic variability and escape from immunity, thus presenting challenges in the development of new vaccines capable of generating broadly sterilizing immunity. One potential vaccine target is the induction of antibody that disrupts the interaction between the macrophage CD163 receptor and the GP2, GP3, and GP4 heterotrimer that protrudes from the surface of the virion. Studies to understand this interaction by mapping mutations that appear following the escape of virus from neutralizing antibody identify the ectodomain regions of GP5 and M as important immune sites. As a target for antibody, GP5 possesses a conserved epitope flanked by N-glycosylation sites and hypervariable regions, a pattern of conserved epitopes shared by other viruses. Resolving this apparent conundrum is needed to advance PRRS vaccine development.

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