A rapid, specific, and sensitive quantitative PCR assay was developed for the detection of Porcine Teschovirus (PTV). Specific primers were designed on the basis of conserved regions of complete PTV genome sequences retrieved from GenBank, and a recombinant plasmid was constructed to generate a standard curve. Reaction conditions were optimized, and the sensitivity, specificity, and reproducibility of the assay were systematically evaluated. The detection limit of the Reverse Transcription Quantitative PCR(RT-qPCR) assay was 1 & times;101 copies/mu L, which was approximately 100-fold more sensitive than that of conventional PCR (1 & times;103 copies/mu L). A single melting curve peak confirmed the specificity of the assay, and no cross-reactivity was observed with other common porcine viruses. The coefficient of variation was less than 1.1%, indicating excellent reproducibility. Application of the established method to 541 clinical samples revealed a positive rate of 68.4%, consistent with conventional PCR results. These results demonstrate that the developed RT-qPCR assay is a reliable tool for the detection, surveillance, and epidemiological investigation of PTV.

Porcine circovirus type 2 (PCV2) is one of the major pathogens currently threatening the global swine industry. The capsid protein (Cap) of PCV2 is a key antigen for developing subunit vaccines. In this study, we established a bioconjugation strategy using chitosan oligosaccharide (COS) to construct a covalently linked PCV2d Cap-COS complex via thiol-maleimide click chemistry. Immunization and challenge experiments in mice demonstrated that when formulated with JLC-3 adjuvant, the PCV2d Cap-COS complex induced stronger and more durable specific immune responses, significantly improved the average daily weight gain postchallenge, and effectively alleviated histopathological damage in the lungs and kidneys. These findings indicate that the PCV2d Cap-COS complex enhances both antigen structure and immunogenicity, offering a novel strategy and experimental evidence for developing high-efficacy PCV2d subunit vaccines.

Introduction:Porcine enteric coronaviruses (PECs) often co-infect swine, leading to high mortality, which underscores the need for multivalent vaccines. Methods:A trivalent mRNA vaccine was formulated using SM-102 lipid nanoparticles (LNPs) and encodes PEDV-SCOE, PDCoV-SCTD, and TGEV-SAD in a single transcript. BALB/c mice were immunized intramuscularly with escalating doses (5, 10, 15, and 20 µg). Systemic IgG, mucosal IgA, neutralizing antibodies, cytokine profiles (IFN-γ, IL-4), and splenocyte proliferation were assessed. Monovalent formulations and commercial vaccines (PEDV/TGEV bivalent inactivated vaccine from Qilu Animal Health; PDCoV inactivated vaccine from Wuhan Keqian) served as controls. Data are mean ± SD (n = 5); one-way ANOVA with multiple comparisons was applied (*p < 0.05; **p < 0.01; ***p < 0.001). Results:A moderate dose (10 µg) induced systemic IgG, IFN-γ, IL-4, and splenocyte proliferation, indicating activation of both Th1 and Th2 responses. Higher dose (15 µg) preferentially enhanced mucosal IgA and neutralizing antibody responses, exceeding those induced by commercial vaccines, suggesting potential improvement in mucosal protection. Monovalent SM-102-LNP formulations also elicited robust immune responses, approaching commercial benchmarks. Discussion:This trivalent mRNA-LNP vaccine provides broad and potent humoral and cellular immunity in mice, supporting its potential as a platform for porcine vaccination. These results provide preclinical proof-of-concept, and further evaluation in swine is required to assess vaccine efficacy.

PMWS and MPS are severe respiratory diseases in piglets, causing developmental disorders and significant economic losses. The conventional approach to control these diseases relies on separate immunization with individual vaccines, which is time-consuming, labor-intensive, and may induce stress reactions. The aim of this study was to evaluate the immune efficacy of a bivalent inactivated vaccine containing the clinically isolated Mhp Q strain and purified PCV2 Cap VLPs. Thirty-five Changbai piglets were randomly divided into seven groups (n = 5, per group): A (bivalent inactivated vaccine with PCV2 challenged), B (bivalent inactivated vaccine with Mhp challenged), C (commercial PCV2 vaccine with PCV2 challenged), D (commercial Mps vaccine with Mhp challenged), E (sham-vaccinated with PCV2 challenged), F (sham-vaccinated with Mhp challenged), and G (sham-vaccinated with sham challenged). The immune efficacy results demonstrated that 5/5 protection with bivalent inactivated vaccine and 4/5 protection with commercial vaccine against PCV2 challenge, which was consistent with the serology results. The pneumonia lesion scores result demonstrated that the immune protection effect provided by the bivalent inactivated vaccine was comparable to that of the commercial Mps vaccines. Furthermore, the overall clinical trial results indicated that the bivalent inactivated vaccine was safe and controllable, with no adverse reactions observed in both age-matched and non-age-matched pigs. Following immunization, the pigs exhibited significant resistance to infections with both PCV2 and Mhp, reflecting a robust immunoprotective capacity. Collectively, these results support the bivalent inactivated vaccine as a safe and effective strategy for preventing and controlling PMWS and MPS, with promising potential for further clinical development.

Porcine reproductive and respiratory syndrome virus (PRRSV) poses a major challenge to swine health, impairing reproductive performance and causing respiratory disorders in pigs. Thus, it creates a considerable economic burden for the global pig production industry. Current prevention and control strategies for PRRSV remain largely ineffective, necessitating the development of novel antiviral drugs. In the current study, we examined how Verapamil HCl could potentially protect host cells against PRRSV infection using both cellular and animal models. Further, we explored the molecular mechanisms underlying these potential anti-PRRSV effects. We discovered that Verapamil HCl suppresses PRRSV infection in MARC-145 cells, PK-15CD163 cells, and porcine alveolar macrophages. Mechanistic analyses revealed that Verapamil HCl inhibits PRRSV-induced calcium influx in susceptible cells. Additionally, we found that Verapamil HCl enhances heme oxygenase-1 production by activating the p38/Nrf2/Keap-1/HO-1 signaling pathway, subsequently triggering antiviral interferon responses. Finally, animal experiments demonstrated that Verapamil HCl administration significantly reduces viral replication and decreases pulmonary damage in piglets. Collectively, these results suggested that Verapamil HCl may serve as a promising new therapeutic option for treating PRRSV infections.IMPORTANCEVerapamil HCl is known to suppress infections caused by several viruses, including respiratory syncytial virus, bovine herpesvirus 1, and SARS-CoV-2. However, the potential anti-PRRSV mechanisms of Verapamil HCl remain unknown. This study demonstrates that Verapamil HCl exerts anti-PRRSV effects by attenuating the Ca2+ imbalance induced by PRRSV. Furthermore, Verapamil HCl can promote interferon-mediated antiviral responses and reduce pro-inflammatory factor production during PRRSV infection via p38/Nrf2/Keap-1/HO-1 axis activation. These findings indicate that Verapamil HCl could be a very effective treatment agent against PRRSV.

Achieving a balance between enhancing both humoral and cellular immunity while ensuring sustained release for attenuated live vaccines has long been a challenge in the vaccine industry. However, the incorporation of chemical materials as nanoadjuvants has emerged as a promising strategy to address this challenge. In this study, a novel nano-adjuvant with sustained release properties was developed by combining polyethylene glycol (PEG) and other biochemical and molecular biology agents with CpG. The efficacy of this adjuvant was assessed using the widely applied CSF attenuated live vaccine. The body temperature and relative daily weight gain results demonstrated the safety of the formulations. Importantly, the combination of CpG immune enhancers and sustained-release agents led to a synergistic augmentation of both humoral and cellular immune responses. Specifically, the combination of PEG20000 and benzoic acid, along with Seppic white oil, significantly enhanced humoral immunity. In contrast, the combination of total white oil, PEG6000 and benzoic acid demonstrated superior efficacy in promoting cellular immunity. This study offers important insights into enhancing vaccine efficacy through novel adjuvant combinations, which can be applied to the development of more effective vaccines in the future.

Porcine reproductive and respiratory syndrome virus (PRRSV) causes abortion and respiratory disease in swine, hindering the development of the pig farming industry worldwide. However, at present, there are no effective vaccines or drugs for PRRSV control. In this study, we evaluated the inhibitory effect of hyperoside on PRRSV replication in vitro and in vivo and explored the underlying mechanisms. Our results revealed that hyperoside significantly inhibited PRRSV infection in MARC-145 and porcine alveolar macrophages (PAMs). This inhibition was linked to the hyperoside-induced attenuation of pro-inflammatory cytokine (IL-1β, IL-6, IL-8, and TNF-α) upregulation induced by PRRSV infection, which was mediated by the suppression of the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-kB) signaling pathway. Moreover, hyperoside alleviated the autophagy induced by PRRSV via p62/Nrf2/Keap1 signaling pathway activation. In vivo, hyperoside treatment led to an obvious decrease in PRRSV replication in piglets. Therefore, hyperoside may be a useful antiviral agent against PRRSV.IMPORTANCEPorcine reproductive and respiratory syndrome virus (PRRSV) causes abortion and respiratory disease in swine, which induces huge economic losses every year. However, there have been no effective vaccines or drugs for PRRSV control until now. Our present study found that the inhibitory effect of hyperoside on PRRSV replication in vitro and in vivo. Furthermore, we demonstrate that hyperoside inhibits PRRSV proliferation via inhibiting inflammation and autophagy through the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) and p62-Nrf2-Keap1 signaling pathways. Hence, we believe that hyperoside may be a useful antiviral agent to control PRRSV.

Equine herpesvirus-1 (EHV-1) is a significant pathogen that causes substantial economic losses in the equine industry worldwide, which leads to severe respiratory diseases and abortions in horses. However, reports of EHV-1 infection in donkeys are limited, particularly in China. This case study reported an EHV-1-induced respiratory disease in Dezhou donkey foals in Shandong Province, China, in July 2024. Three one-month-old foals exhibited high fever, nasal discharge, and respiratory distress, with a 100% mortality rate. The causative agent, strain LC126, was isolated from a one-month-old donkey foal exhibiting severe respiratory disease. Phylogenetic analysis of the EHV-1 isolate LC126 showed close similarity to EHV-1. Overall, our study revealed that EHV-1 can cause respiratory distress as well as death in donkeys. The study underscores the emerging threat of EHV-1 in donkeys and highlights the need for veterinarians and breeders to give proper attention to the potential threat of EHV-1 outbreaks.

Coronaviruses (CoVs) are implicated in human outbreaks and significant economic losses in the porcine and avian industries. Recent investigations have underscored the potential role of cilia within the respiratory tracts of infected hosts, particularly regarding the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the mechanisms by which other CoVs exert their virulence through ciliary interactions remain inadequately elucidated. In this context, our research has demonstrated that porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) induce ciliary disassembly within six hours post-infection during the early infection stage. Utilizing mass spectrometry, we identified histone deacetylases 6 (HDAC6) or Aurora A (AurA) as binding partners of PEDV or PDCoV membrane (M) proteins. Immunofluorescence studies corroborated that the AurA-HDAC6 axis serves as a principal regulator of ciliary disassembly. Additionally, M proteins from all four CoV genera-PEDV, SARS-CoV-2, PDCoV, and infectious bronchitis virus (IBV)-were observed to congregate at the ciliary base. Molecular techniques, including immunoprecipitation and molecular docking combined with molecular mechanics/generalized born surface area (MM/GBSA) free energy decomposition analysis, further revealed that CoV M proteins interact with both AurA and HDAC6. These interactions depend on conserved residues at the transmembrane-cytosolic junction of M proteins, essential for their binding to the AurA-HDAC6 axis. Mutations disrupting these residues significantly impaired the binding affinity, thus inhibiting the associated ciliary disassembly process. Collectively, our findings illuminate a conserved regulatory mechanism involving CoV M proteins across all four genera, contributing to ciliary disassembly during early infection. This work enhances our understanding of the fundamental interactions between CoVs and host cells, positioning AurA and HDAC6 as potential therapeutic targets for a broad spectrum of CoV infections.

Exosomes, which are small membrane-enclosed vesicles, are actively released into the extracellular space by a variety of cells. Growing evidence indicates that exosomes derived from virus-infected cells can selectively encapsulate viral proteins, genetic materials, or even entire virions. This enables them to mediate cell-to-cell communication and facilitate virus transmission. Classical swine fever (CSF) is a disease listed by the World Organisation for Animal Health (WOAH) Terrestrial Animal Health Code and must be reported to the organisation. It is caused by classical swine fever virus (CSFV) belonging to the Flaviviridae family. Recent studies have demonstrated that extracellular vesicles originating from autophagy can facilitate the antibody-resistant spread of classical swine fever virus. However, due to the extreme difficulty in achieving a complete separation from virions, the role of exosomes during CSFV infection and proliferation remains elusive. In this study, we ingeniously chose to perform immunoprecipitation (IP) targeting the CSFV E2 protein, thereby achieving the complete removal of infectious virions. Subsequently, we discovered that the purified exosomes are shown to contain viral genomic RNA and partial viral proteins. Furthermore, exosomes secreted by CSFV-infected cells can evade CSFV-specific neutralizing antibodies, establish subsequent infection, and stimulate innate immune system after uptake by recipient cells. In summary, exosomes play a critical role in CSFV transmission. This is of great significance for in-depth exploration of the characteristics of CSFV and its complex interactions with the host.

Classical swine fever (CSF) is a severe disease caused by the highly contagious CSFV. Our previous study demonstrated that exosomes from CSFV-infected cells contained significant amounts of viral genome and Core (C) protein and were infectious. To further elucidate the mechanisms underlying the formation of these infectious exosomes, we investigated the intracellular transport of the C protein in this study.We first identified the synchronized transport of the C protein and viral genome to exosomes, distinguishing it from other structural proteins. This suggests that the C protein likely binds to the viral genome and is transported to exosomes as a nucleocapsid. Subsequently, Co-IP and co-localization experiments confirmed the interaction between the host Myosin 1B (MYO1B) protein and the C protein. Key interaction sites were identified by generating and analyzing various C protein point mutations and truncation variants. The results indicate that specific sites at the N-terminus of the C protein significantly impact its interaction with MYO1B. Ultimately, by modulating MYO1B expression, we found that MYO1B knockdown significantly reduced the C protein and viral genome content in exosomes, leading to a decrease in CSFV titers. These findings underscore the critical role of MYO1B in facilitating the transport of the C protein and viral genome into exosomes during CSFV infection.Overall, this study explores the mechanism of infectious exosome formation during CSFV infection, revealing the critical role of the host MYO1B in this process. This is the first study to identify the involvement of MYO1B in viral infection, not only offering important insights into host-virus interactions but also identifying a new target for antiviral drug development.

Porcine circovirus type 2 (PCV2) is a globally prevalent infectious pathogen affecting swine, with its capsid protein (Cap) being the sole structural protein critical for vaccine development. Prior research has demonstrated that PCV2 Cap proteins produced in Escherichia coli (E. coli) can form virus-like particles (VLPs) in vitro, and nuclear localization signal peptides (NLS) play a pivotal role in stabilizing PCV2 VLPs. Recently, PCV2d has emerged as an important strain within the PCV2 epidemic. In this study, we systematically optimized the PCV2d Cap protein and successfully produced intact PCV2d VLPs containing NLS using E. coli. The recombinant PCV2d Cap protein was purified through affinity chromatography, yielding 7.5 mg of recombinant protein per 100 ml of bacterial culture. We augmented the conventional buffer system with various substances such as arginine, β-mercaptoethanol, glycerol, polyethylene glycol, and glutathione to promote VLP assembly. The recombinant PCV2d Cap self-assembled into VLPs approximately 20 nm in diameter, featuring uniform distribution and exceptional stability in the optimized buffer. We developed the vaccine and immunized pigs and mice, evaluating the immunogenicity of the PCV2d VLPs vaccine by measuring PCV2-IgG, IL-4, TNF-α, and IFN-γ levels, comparing them to commercial vaccines utilizing truncated PCV2 Cap antigens. The HE staining and immunohistochemical tests confirmed that the PCV2 VLPs vaccine offered robust protection. The results revealed that animals vaccinated with the PCV2d VLPs vaccine exhibited high levels of PCV2 antibodies, with TNF-α and IFN-γ levels rapidly increasing at 14 days post-immunization, which were higher than those observed in commercially available vaccines, particularly in the mouse trial. This could be due to the fact that full-length Cap proteins can assemble into more stable PCV2d VLPs in the assembling buffer. In conclusion, our produced PCV2d VLPs vaccine elicited stronger immune responses in pigs and mice compared to commercial vaccines. The PCV2d VLPs from this study serve as an excellent candidate vaccine antigen, providing insights for PCV2d vaccine research.

For any simple-root constacyclic code $\mathcal{C}$ over a finite field $\mathbb{F}_q$, as far as we know, the group $\mathcal{G}$ generated by the multiplier, the constacyclic shift and the scalar multiplications is the largest subgroup of the automorphism group ${\rm Aut}(\mathcal{C})$ of $\mathcal{C}$. In this paper, by calculating the number of $\mathcal{G}$-orbits of $\mathcal{C}\backslash\{\bf 0\}$, we give an explicit upper bound on the number of non-zero weights of $\mathcal{C}$ and present a necessary and sufficient condition for $\mathcal{C}$ to meet the upper bound. Some examples in this paper show that our upper bound is tight and better than the upper bounds in [Zhang and Cao, FFA, 2024]. In particular, our main results provide a new method to construct few-weight constacyclic codes. Furthermore, for the constacyclic code $\mathcal{C}$ belonging to two special types, we obtain a smaller upper bound on the number of non-zero weights of $\mathcal{C}$ by substituting $\mathcal{G}$ with a larger subgroup of ${\rm Aut}(\mathcal{C})$. The results derived in this paper generalize the main results in [Chen, Fu and Liu, IEEE-TIT, 2024]}.

IntroductionEquid herpesvirus type 8 (EqHV-8) poses a significant threat to equine health, leading to miscarriages and respiratory diseases in horses and donkeys, and results in substantial economic losses in the donkey industry. Currently, there are no effective drugs or vaccines available for EqHV-8 infection control.MethodsIn this study, we investigated the in vitro and in vivo antiviral efficacy of Blebbistatin, a myosin II ATPase inhibitor, against EqHV-8.ResultsOur results demonstrated that Blebbistatin significantly inhibited EqHV-8 infection in Rabbit kidney (RK-13) and Madin-Darby Bovine Kidney (MDBK) cells in a concentration-dependent manner. Notably, Blebbistatin was found to disrupt EqHV-8 infection at the entry stage by modulating myosin II ATPase activity. Moreover, in vivo experiments revealed that Blebbistatin effectively reduced EqHV-8 replication and mitigated lung pathology in a mouse model.ConclusionCollectively, these findings suggest that Blebbistatin holds considerable potential as an antiviral agent for the control of EqHV-8 infection, presenting a novel approach to addressing this veterinary challenge.

Productivity and stability of Pseudorabies virus (PRV) are critical for the manufacture and storage of live attenuated pseudorabies vaccine. Trehalose is commonly used as a cryoprotectant to stabilize organisms during freezing and lyophilization. Trehalose transporter 1 (Tret1), derived from Polypedilum vanderplanki, can deliver trehalose with a reversible transporting direction. In this study, we demonstrated that productivity and stability of PRV proliferated in recombinant ST cells with stable expression of Tret1 were enhanced. As a result, a five-fold increase of intracellular trehalose amount was observed, and the significant increase of progeny viral titer was achieved in recombinant cells with the addition of 20 mM trehalose. Particularly, after storage for 8 weeks at 20 degrees C, the loss of viral titer was 0.8 and 1.7 lgTCID50/mL lower than the control group with or without the addition of trehalose. Additionally, the freeze-thaw resistance at -20 degrees C and -70 degrees C of PRV was significantly enhanced. Furthermore, according to standard international protocols, a series of tests, including karyotype analysis, tumorigenicity, and the ability of proliferation PRV, were conducted. Our results demonstrated that the recombinant ST cell with Tret1 is a promising cell substrate and has a high potential for producing more stable PRV for the live attenuated vaccine.

Porcine Circovirus (PCV) includes Porcine Circovirus 1(PCV1), Porcine Circovirus 2 (PCV2) and Porcine Circovirus 3 (PCV3). In recent years, co-infection exists between PCV1, PCV2 and PCV3 serotypes. Therefore, it is particularly necessary to establish a fast, specific and sensitive SYBR Green I real-time quantitative PCR detection method for PCV1, PCV2 and PCV3. In this experiment, specific primers were selected and the reaction conditions were optimized. A real-time quantitative PCR identification method was established. The results showed the detection limits of this assay were 40.3 copies/μl for PCV1, 25.2 copies/μl for PCV2 and22.4 copies/ μl for PCV3. There was no cross-reactivity with swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine pseudorabies virus (PRV) and porcine parvovirus (PPV). The intra-assay and inter-assay coefficients of variation were less than 1%. The test results of 100 PCV suspected positive samples revealed that the PCV1, PCV2 and PCV3 singular infection rate was 10% (10/100), 64% (64/100) and 52% (52/100), respectively. The PCV1 and PCV2 co-infection rate was 8% (8/100), the PCV1 and PCV3 co-infection rate was 7% (7/100), the PCV2 and PCV3 co-infection rate was 26% (26/100), and the PCV1, PCV2 and PCV3 co-infection rate was 7% (7/100). This method has good specificity, sensitivity and stability. It provides a promising tool for rapid differential detection of PCV1, PCV2 and PCV3.

The anaphase promoting complex/cyclosome (APC/C) and its cofactors CDH1 and CDC20 regulate the accumulation/degradation of CCNB1 during mouse oocyte meiotic maturation. Generally, the CCNB1 degradation mediated by APC/CCDC20 activity is essential for the transition from metaphase to anaphase. Here, by using siRNA and mRNA microinjection, as well as time-lapse live imaging, we showed that Septin 9, which mediates the binding of septins to microtubules, is critical for oocyte meiotic cell cycle progression. The oocytes were arrested at the MI stage and the connection between chromosome kinetochores and spindle microtubules was disrupted after Septin 9 depletion. As it is well known that spindle assembly checkpoint (SAC) is an important regulator of the MI-AI transition, we thus detected the SAC activity and the expression of CDC20 and CCNB1 which were the downstream proteins of SAC during this critical period. The signals of Mad1 and BubR1 still remained on the kinetochores of chromosomes in Septin 9 siRNA oocytes at 9.5 h of in vitro culture when most control oocytes entered anaphase I. The expression of CCNB1 did not decrease and the expression of CDC20 did not increase at 9.5 h in Septin 9 siRNA oocytes. Microinjection of mRNA encoding Septin 9 or CDC20 could partially rescue MI arrest caused by Septin 9 siRNA. These results suggest that Septin 9 is required for meiotic MI-AI transition by regulating the kinetochore-microtubule connection and SAC protein localization on kinetochores, whose effects are transmitted to APC/CCDC20 activity and CCNB1 degradation in mouse oocytes.

Pseudorabies virus (PRV) is a pathogen of swine resulting in devastating disease. Some viral infections can cause endoplasmic reticulum (ER) stress and unfolded protein response (UPR) to restore ER homeostasis. However, the mechanism of how PRV induces ER stress and UPR activation remains unclear. Here, levels of proteins or transcriptional factors of three UPR pathways were examined in suspension-cultured BHK-21 cells to investigate PRV-induced ER stress. Results showed that PRV triggered ER stress and UPR of the host cells with the upregulated expression of glucose-related protein 78 kD and 94 kD (GRP78 and GRP94). The protein kinase RNA-like ER kinase (PERK) pathway was activated to upregulate ATF4, CHOP, and GADD34 expression. Additionally, the inositol requiring kinase 1 (IRE1) pathway was triggered by splicing of X box-binding protein 1 (XBP1) mRNA and the enhanced expression of p58IPK and EDEM1. Furthermore, our data demonstrated that PRV took advantage of ER stress to accelerate its replication with the activation of the PERK and IRE1 pathways in suspension-cultured BHK-21 cells, and the glycoprotein B played a crucial role in ER stress.

为考察BHK-21悬浮细胞增殖伪狂犬病毒(Pseudorabies virus,PRV)工艺参数及病毒增殖过程中代谢动力学,将PRV接种于BHK-21悬浮细胞,考察接毒时细胞密度、病毒感染复数(MOI)及收毒时间对病毒效价的影响,测定培养过程中葡萄糖(Gluc)、乳酸(Lac)和谷氨酰胺(Gln)浓度,计算病毒增殖过程中各参数代谢速率.结果显示,将MOI为0.01的PRV病毒接种BHK-21悬浮细胞,其病毒滴度在42 h达最高8.5 lgTCID50/mL.代谢参数检测结果表明,BHK-21细胞在接毒36 h后细胞开始出现死亡.PRV在BHK-21悬浮细胞中的增殖特性为伪狂犬病毒的规模化培养及疫苗开发提供了技术基础.

Pseudorabies virus (PRV) is a pathogen of swine resulting in devastating disease. Some viral infections can cause endoplasmic reticulum (ER) stress and unfolded protein response (UPR) to restore ER homeostasis. However, the mechanism of how PRV induces ER stress and UPR activation remains unclear. Here, levels of proteins or transcriptional factors of three UPR pathways were examined in suspension-cultured BHK-21 cells to investigate PRV-induced ER stress. Results showed that PRV triggered ER stress and UPR of the host cells with the upregulated expression of glucose-related protein 78 kD and 94 kD (GRP78 and GRP94). The protein kinase RNA-like ER kinase (PERK) pathway was activated to upregulate ATF4, CHOP, and GADD34 expression. Additionally, the inositol requiring kinase 1 (IRE1) pathway was triggered by splicing of X box-binding protein 1 (XBP1) mRNA and the enhanced expression of p58 IPK and EDEM1. Furthermore, our data demonstrated that PRV took advantage of ER stress to accelerate its replication with the activation of the PERK and IRE1 pathways in suspension-cultured BHK-21 cells, and the glycoprotein B played a crucial role in ER stress.