Porcine Reproductive and Respiratory Syndrome Virus nsp11 Antagonizes Broad Antiviral Effects of MCPIP1 by Inducing Interleukin-17 Expression.

Monocyte chemotactic protein-induced protein 1 (MCPIP1) is an inflammatory regulator in immune response and has broad antiviral effects by targeting viral RNA. Porcine reproductive and respiratory syndrome virus (PRRSV), a major viral pathogen in pigs, causes immune suppression leading to coinfection of swine pathogens, but the mechanisms are not fully clarified. In this study, MCPIP1 expression was found to be significantly upregulated in lungs of PRRSV-infected piglets, as well as in Marc-145 and porcine pulmonary alveolar macrophage (PAM) cells upon PRRSV stimulation. MCPIP1 overexpression significantly inhibited PRRSV replication, while MCPIP1 knockdown increased the virus titer. Various mutations in RNase functional domains of MCPIP1 impaired the inhibitory activity against PRRSV, while those in deubiquitinase domains failed to do so. MCPIP1 expression started to decrease from 60 h after PRRSV infection in PAMs. Meanwhile, infection with higher dose of PRRSV further downregulated MCPIP1, indicating the antagonizing effects from PRRSV against MCPIP1. Moreover, it was confirmed that MCPIP1 expression was downregulated in 3D4 cells with either interleukin-17 (IL-17) or nsp11 overexpression, while IL-17 inhibitor abolished the decrease of MCPIP1 caused by nsp11, indicating nsp11 employs IL-17 induction to inhibit MCPIP1. Furthermore, the PRRSV nsp11 mutant with a deficiency in IL-17 induction showed the recovered expression of MCPIP1 in infected cells, inspiring a strategy for virus attenuation. This is the first report about the role of MCPIP1 against PRRSV and the function of PRRSV nsp11 against innate immunity to facilitate virus replication via IL-17. The study not only illuminates PRRSV infection machinery but also enlightens alternative antiviral strategies, such as vaccine candidates. IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) suppresses the innate immunity and leads to coinfection of swine pathogens. Monocyte chemotactic protein-induced protein 1 (MCPIP1) is a broad-spectrum host antiviral protein. Therefore, to further clarify the mechanism of PRRSV against innate immunity, we explored the relationship between MCPIP1 and PRRSV infection. The results showed that MCPIP1 inhibited PRRSV infection in the early stage of virus infection. Importantly, PRRSV nsp11 subsequently employed IL-17 induction to suppress MCPIP1 expression and antagonized anti-PRRSV effects. Furthermore, PRRSV with mutation of nsp11 S74A failed to induce MCPIP1 reduction. These findings confirmed the function of MCPIP1 against PRRSV and revealed that PRRSV nsp11 plays an important role in virus against innate immunity. This study enlightens a new strategy to develop safer attenuated vaccines against PRRSV by nsp11 mutation.

Identification of E2 with improved secretion and immunogenicity against CSFV in piglets.

BACKGROUND: Outbreaks of Classical swine fever virus (CSFV) cause significant economic losses in the swine industry. Vaccination is the major method to prevent and control the disease. As live attenuated vaccines fail to elicit differentiable immunity between infected and vaccinated animals, subunit vaccine was considered as an alternative candidate to prevent and eradicate CSFV. Subunit vaccines present advantages in DIVA immunogenicity and safety. The technology was limited due to the low yield and the high cost with multiple and large doses. The native E2 signal peptide has not been well defined before. Here, the aim of this study is to develop a cost-effective and efficacious E2 vaccine candidate against CSFV with signal peptide and E2 sequence selection. RESULTS: A novel CSFV E2 sequence (E2ZJ) was identified from an epidemic strain of Zhejiang for outstanding secretion in baculovirus and enhanced immunogenicity. E2 secretion induced with the selected signal peptide, SPZJ (SP23), increase at least 50% as compared to any other signal peptides tested. Besides, unique antigenic features were identified in E2ZJ. As indicated with immunized sera in IFA against CSFV infection, E2ZJ elicited CSFV antibodies at the earlier stage than other E2 types tested in mice. Moreover, higher level of neutralizing and CSFV antibodies against CSFV with E2ZJ was detected than other E2s with the same dosage at 28 dpi. Further, E2ZJ successfully elicited neutralizing immunity in piglets. A single dose of 5 µg of E2ZJ was sufficient to induce protective antibodies against CSFV in piglets and provided 100% protection against lethal virus challenge. CONCLUSIONS: Our studies provide evidence that E2ZJ guided by a novel E2 signal peptide (SPZJ) was efficiently secreted and presented significantly improved immunogenicity than conventional E2 vaccines. Moreover, a single dose of 5 µg E2ZJ is efficacious against CSFV in piglets.

Ketamine attenuates high mobility group box-1-induced inflammatory responses in endothelial cells.

BACKGROUND: High mobility group box-1 (HMGB1) acts as an inflammatory mediator and has been implicated in pathophysiological damage of vascular inflammatory diseases. Ketamine, an anesthetic agent with sedative and analgesic properties, has been shown to have potent anti-inflammatory effects in a variety of models of systemic inflammation. However, the effects of ketamine on HMGB1-mediated proinflammatory responses have not been fully investigated. In the present study, we investigated the effects of ketamine on HMGB1-activated endothelial cells and explored the underlying mechanisms. METHODS: Human endothelial cells were incubated with or without HMGB1 (1 µg/mL) in the presence or absence of ketamine, an nuclear factor (NF)-κB inhibitor (PDTC), anti-toll-like receptor (TLR)2/4 antibody, or small interfering RNA (siRNA). The anti-inflammatory activities of ketamine were determined by measuring solute flux, leukocyte adhesion and migration, and activation of proinflammatory proteins in HMGB1-activated endothelial cells. The effect of ketamine on TLR-2/4 and NF-κB activation was evaluated using enzyme-linked immunosorbent assays and immunofluorescence confocal microscopy assay. RESULTS: We found that ketamine inhibited the HMGB1-mediated barrier disruption, neutrophil adhesion and migration, and expression of cell adhesion molecules in a dose-dependent manner. Furthermore, ketamine downregulated the TLR-2 and -4, expression in HMGB1-activated endothelial cells. Treatment with ketamine also significantly inhibited the activation of TLR2/4 and the nuclear translocation of NF-κB p50/p65. Furthermore, our study shows that the HMGB1-induced release of inflammatory mediators was suppressed by PDTC, anti-TLR2/4 antibody, and siRNA. CONCLUSIONS: Our study has demonstrated that ketamine exerts anti-inflammatory effects in HMGB1-mediated proinflammatory responses in a dose-dependent manner. The mechanism responsible for these effects involves the TLR2/4 and NF-κB signaling pathway.

[Rat prostate glandular epithelial cells cultured in vitro and their barrier function].

OBJECTIVE: To culture rat prostate glandular epithelial cells and study their barrier functions in vitro. METHODS: Rat prostate glandular epithelial cells were cultured in vitro. The expression of the tight junction protein claudin-1 was determined by immunohistochemistry, the structure and composition of the epithelial cells observed under the inverted microscope and transmission electron microscope. The transepithelial electrical resistances (TEERs) were monitored with the Millicell system. The permeability of the prostate glandular epithelial cells was assessed by the phenol red leakage test. RESULTS: Compact monolayer cell structures were formed in the prostate glandular epithelial cells cultured in vitro. Immunohistochemistry showed the expression of the tight junction protein claudin-1 and transmission electron microscopy confirmed the formation of tight junctions between the adjacent glandular epithelial cells. The TEERs in the cultured prostate glandular epithelial cells reached the peak of about (201.3 ± 3.5) Ω/cm2 on the 8th day. The phenol red leakage test manifested a decreased permeability of the cell layers with the increase of TEERs. CONCLUSION: The structure and function of rat prostate glandular epithelial cells are similar to those of brain capillary endothelial cells, retinal capillary endothelial cells, and intestinal epithelial cells. In vitro cultured prostate glandular epithelial cells have the barrier function and can be used as a model for the study of blood prostate barrier in vitro.

The Roles of Tight Junctions and Claudin-1 in the Microbubble-Mediated Ultrasound-Induced Enhancement of Drug Concentrations in Rat Prostate.

Although microbubble-mediated ultrasound irradiation can enhance the prostate permeability, little is known about the mechanism. In our study, the healthy, adult male SD rats were divided into four groups: the BC, US, MB, and MMUS groups. A therapeutic ultrasound apparatus was used to treat the rats prostates in the presence of circulating MBs. Cefuroxime was injected to assess prostate permeability by HPLC. The structures of prostate tissues and TJs were observed by light and transmission electron microscopy. Western blot was used to assess claudin-1 expression. After treatment of microbubble-mediated ultrasound irradiation, the cefuroxime concentrations in the prostate were significantly increased. HE staining demonstrated that the gland epithelial cell layer became dropsical, thick, and disordered. In transmission electron microscopy, the TJs between adjacent capillary endothelial cells or gland epithelial cells were disjointed and partly interrupted. Furthermore, western blot showed the expression of claudin-1 was significantly decreased. However, these findings were not observed in the prostates exposed to microbubble or ultrasound alone, as well as the healthy control rats. In conclusion, microbubble-mediated ultrasound irradiation significantly enhanced the prostate permeability and improve the cefuroxime concentrations in prostate. The changes in TJs structure and the decreased claudin-1 expression may play important roles in this process.

Vitamin E Intake and Risk of Renal Cell Carcinoma: A Meta-Analysis of 7 Case-Control Studies.

OBJECTIVE: Vitamin E intake may reduce the risk of renal cell carcinoma, but the results were inconsistent. Hence, we conducted a meta-analysis to assess the association between dietary vitamin E intake and the risk of renal cell carcinoma. METHODS: We searched PubMed to identify the relevant case-control studies up to June 2014. Reference lists of retrieved articles were also reviewed. Odds ratios and corresponding 95% confidence intervals were used to estimate the association between dietary vitamin E intake and the risk of renal cell carcinoma. RESULTS: We identified 7 case-control studies regarding dietary vitamin E intake and risk of renal cell carcinoma, involving 5789 cases and 14866 controls. The odds ratio of renal cell carcinoma for the highest compared with the lowest dietary vitamin E intake was 0.75 (95% confidence interval: 0.59-0.91), and heterogeneity was observed across studies. The association between dietary vitamin E intake and the risk of renal cell carcinoma was not significantly differed by gender, but this association were inconsistent in the North American and European populations. CONCLUSION: Our study provided a evidence that there was a significant inverse association of dietary vitamin E intake with risk of renal cell carcinoma. However, this finding was based on the case-control studies, more well-designed cohort studies are needed.

[Bone marrow mesenchymal stem cells suppress E coli-induced bacterial prostatitis in rats].

OBJECTIVE: To investigate the inhibitory effect of bone marrow mesenchymal stem cells (BMSCs) on E coliinduced prostatitis in rats. METHODS: BMSCs were isolated, cultured and amplified by the attached choice method. Fifty SD rats were randomized into five groups of equal number: normal control, acute bacterial prostatitis (ABP) , chronic bacterial prostatitis (CBP), ABP + BMSCs, and CBP + BMSCs, and the animals in the latter four groups were injected with E. coli into both sides of the prostate under ultrasound guidance for 1 - 14 days to induce ABP and for 4 - 12 weeks to induce CBP. The control rats were injected with the same amount of PBS. Two weeks after injection of BMSCs into the prostates, pathomorphological changes in the prostate were observed under the light microscope and the mRNA and protein levels of IL-1ß and TNF-α determined by RT-PCR and ELISA, respectively, followed by statistical analysis with SPSS 18.0. RESULTS: Histopathological evaluation showed typical pathological inflammatory changes in the prostates of the rats in the ABP and CBP groups, including glandular structural changes, interstitial edema, inflammatory cell infiltration, and fibrous hyperplasia, which were all remarkably relieved after treated with BMSCs. The mRNA and protein levels of IL-ß ([0.829 ± 0.121] and [271.75 ± 90.59] pg/ml) and TNF-α ([0.913 ± 0. 094] and [105.78 ± 19. 05] pg/ml) in the ABP and those of IL-1ß ([0. 975 ± 0. 114] and [265. 31 ± 71. 34] pg/ml) and TNF-α ([0. 886 ± 0. 084] and [107. 45 ± 26. 11 ] pg/ml) in the CBP groups were significantly higher than those in the control rats ([0. 342 ± 0.087] and [45.76 17. 99] pg/ml, P <0. 05); ([0.247 ± 0.054] and ([19.42 ± 7. 75] pg/ml, P <0. 01) as well as than those in the ABP + BMSCs ([0. 433 ± 0. 072] and [51. 34 ± 22. 13] pg/ml, P < 0. 05 ) ; ( [0. 313 ± 0. 076] and [28. 38 ± 8. 78] pg/ml, P < 0. 01) and the CBP + BMSCs group ([0.396 ± 0.064] and [56.37 ± 21.22] pg/ml, P <0.05); ([0.417 ± 0.068] and [29.21 ± 10.22] pg/ml, P <0.01). CONCLUSION: Injection of BMSCs can reduce E coli-induced prostatic inflammation reaction, which.may be associated with its reduction of inflammatory cell infiltration and the expressions of IL-1ß and TNF-α in the prostate tissue.

Optimal control strategy design based on dynamic programming for a dual-motor coupling-propulsion system.

A dual-motor coupling-propulsion electric bus (DMCPEB) is modeled, and its optimal control strategy is studied in this paper. The necessary dynamic features of energy loss for subsystems is modeled. Dynamic programming (DP) technique is applied to find the optimal control strategy including upshift threshold, downshift threshold, and power split ratio between the main motor and auxiliary motor. Improved control rules are extracted from the DP-based control solution, forming near-optimal control strategies. Simulation results demonstrate that a significant improvement in reducing energy loss due to the dual-motor coupling-propulsion system (DMCPS) running is realized without increasing the frequency of the mode switch.

[Prostate stem cells: an update].

Stem cells are characterized by self-renewing, multipotent differentiation, and high proliferation and receiving more and more attention for their roles in the development and management of various diseases. There are epithelial stem cells and mesenchymal stem cells in the prostate. The markers of the epithelial stem cells include cytokeratin, stem cell antigen-1, and integrins alpha2beta1, CD49f, CD133, CD117, and CD44. The markers of the mesenchymal stem cells include CD30, CD44, CD133, neuron-specific enolase, and vascular endothelial growth factor receptor-1. Prostate stem cells are involved in the development and treatment of prostatic diseases. This review focuses on the latest progress in the studies of prostate stem cells.

Phrenic nerve stimulation protects against mechanical ventilation-induced diaphragm dysfunction in rats.

INTRODUCTION: We investigated a novel application of phrenic nerve stimulation (PNS) in diaphragm dysfunction induced by mechanical ventilation (MV). METHODS: Twenty-one Sprague-Dawley rats were assigned randomly to 3 groups: spontaneous breathing, 18-h controlled MV, and 18-h controlled MV with PNS. Upon completion of the experimental protocol, diaphragm contractility, gene expression of insulin-like growth factor-1 (IGF-1) and ubiquitin ligases, and serum IGF-1 levels were analyzed. RESULTS: Compared with the spontaneously breathing rats, impaired diaphragm contractile function, including force-related properties and force-frequency responses, were pronounced with MV. Furthermore, MV suppressed IGF-1 and induced muscle ring finger 1 mRNA expression in the diaphragm. In contrast, PNS counteracted MV-induced gene expression changes in the diaphragm and restored diaphragm function. CONCLUSIONS: PNS exerted a protective effect against MV-induced diaphragm dysfunction by counteracting altered expression of IGF-1 and ubiquitin ligase in the diaphragm.

Dexmedetomidine inhibits the secretion of high mobility group box 1 from lipopolysaccharide-activated macrophages in vitro.

BACKGROUND: High mobility group box 1 (HMGB1) is a critical proinflammatory factor that is closely related to mortality in sepsis patients. Dexmedetomidine has been proven to reduce the mortality rate from endotoxin shock and attenuate endotoxin-induced acute lung injury. These effects result from reduced secretion of many proinflammatory mediators, although it is not clear whether dexmedetomidine affects the secretion of HMGB1. In this study, we explored the effect of dexmedetomidine on the expression and secretion of HMGB1 from lipopolysaccharide (LPS)-activated macrophages. METHODS: We incubated RAW264.7 cells with LPS in the presence or absence of various concentrations of dexmedetomidine. We used an enzyme-linked immunosorbent assay to detect the secretion levels of HMGB1 in the culture supernatant. We employed real-time polymerase chain reaction to assess the expression of HMGB1 mRNA, and used a nuclear/cytoplasm extraction kit to extract the nuclear and cytoplasmic proteins. We employed Western blotting to observe changes in the translocation of HMGB1 from the nucleus to the cytoplasm. In addition, we used a nuclear factor (NF)-κB p50/p65 transcription factor assay kit to analyze NF-κB activity in the nuclear extract. RESULTS: Dexmedetomidine inhibited the translocation of HMGB1 from the nucleus to the cytoplasm and its extracellular secretion in LPS-activated macrophages while suppressing the expression of HMGB1 mRNA. Dexmedetomidine inhibited the translocation of NF-κB from the cytoplasm to the nucleus in LPS-activated macrophages in a dose-dependent manner. Moreover, these effects were significantly reversed by the α2-adrenergic receptor antagonist yohimbine. CONCLUSIONS: Our study demonstrates that dexmedetomidine inhibits the translocation of HMGB1 from the nucleus to the cytoplasm and the expression of HMGB1 mRNA at clinically relevant dosages. The mechanism responsible for these effects may be through the NF-κB signaling pathway and the α2-adrenergic receptors.

Porcine Reproductive and Respiratory Syndrome Virus Adapts Antiviral Innate Immunity via Manipulating MALT1.

To fulfill virus replication and persistent infection in hosts, viruses have to find ways to compromise innate immunity, including timely impedance on antiviral RNases and inflammatory responses. Porcine reproductive and respiratory syndrome virus (PRRSV) is a major swine pathogen causing immune suppression. MALT1 is a central immune regulator in both innate and adaptive immunity. In this study, MALT1 was confirmed to be induced rapidly upon PRRSV infection and mediate the degradation of two anti-PRRSV RNases, MCPIP1 and N4BP1, relying on its proteolytic activity, consequently facilitating PRRSV replication. Multiple PRRSV nsps, including nsp11, nsp7ß, and nsp4, contributed to MALT1 elicitation. Interestingly, the elevated expression of MALT1 began to decrease once intracellular viral expression reached a high enough level. Higher infection dose brought earlier MALT1 inflection. Further, PRRSV nsp6 mediated significant MALT1 degradation via ubiquitination-proteasome pathway. Downregulation of MALT1 suppressed NF-κB signals, leading to the decrease in proinflammatory cytokine expression. In conclusion, MALT1 expression was manipulated by PRRSV in an elaborate manner to antagonize precisely the antiviral effects of host RNases without excessive and continuous activation of inflammatory responses. These findings throw light on the machinery of PRRSV to build homeostasis in infected immune system for viral settlement. IMPORTANCE PRRSV is a major swine pathogen, suppresses innate immunity, and causes persistent infection and coinfection with other pathogens. As a central immune mediator, MALT1 plays essential roles in regulating immunity and inflammation. Here, PRRSV was confirmed to manipulate MALT1 expression in an accurate way to moderate the antiviral immunity. Briefly, multiple PRRSV nsps induced MALT1 protease to antagonize anti-PRRSV RNases N4BP1 and MCPIP1 upon infection, thereby facilitating viral replication. In contrast, PRRSV nsp6 downregulated MALT1 expression via ubiquitination-proteasome pathway to suppress the inflammatory responses upon infection aggravation, contributing to immune defense alleviation and virus survival. These findings revealed the precise expression control on MALT1 by PRRSV for antagonizing antiviral RNases, along with recovering immune homeostasis. For the first time, this study enlightens a new mechanism of PRRSV adapting antiviral innate immunity by modulating MALT1 expression.

Broad antiviral peptides against PRRSV based on novel linear epitopes on porcine CD163.

PRRSV causes major economic losses to swine industry world-wide, which requires innovative antiviral agents. Porcine scavenger receptor CD163 has been identified as an essential fusion receptor for Porcine reproductive and respiratory Syndrome Virus (PRRSV) infection. In this study, novel antiviral peptides from pCD163 against PRRSV were developed based on broad neutralizing monoclonal antibodies. SRCR-5-9 of pCD163 from baculovirus efficiently binds to PRRSVs of lineage 8 and lineage 1, blocking infection in PAMs. A batch of monoclonal antibodies targeting SRCR-5-9 were generated and characterized. 8H2 and 4H7 block PRRSV infection by the disruption in viral attachment to PAMs. Virus titer reduced 100-1000 folds in average and the virus copy number decreased about 104 folds with these antibodies. Linear epitopes of 8H2 and 4H7 were individually localized in SRCR6 (1-30 aa) and PSTI(1-15aa) of pCD163. Mutations of SRCR6 NI1718KT and PST SS1314AA abolished the recognition of 8H2 and 4H7 to the corresponding region individually. Peptides derived from the linear epitopes displayed a broad inhibitory effect on PRRSVs of different lineages in a dose-dependent manner and further modulated PRRSV-related NF-κB pathway. In conclusion, these findings deepen the understanding in the interaction between PRRSV and pCD163 receptor and provide alternative universal antiviral strategies against PRRSV.

Broad neutralization of CSFV with novel monoclonal antibodies in vivo.

Classical swine fever is a highly contagious disease in China. Although vaccination against Classical swine fever virus (CSFV) has been widely carried out in China, CSFV cases still emerge in an endless stream. Therefore, it is necessary to take new antiviral measures to eliminate CSFV. Glycoprotein E2 of CSFV is the major vaccine candidate that confers protective immunity. Thus, in this study, a batch of neutralizing monoclonal antibodies (mAbs) against E2, as alternative antiviral strategies, were produced. Among them, mAbs 6D10, 8D8 and 3C12 presented neutralizing reactivity against CSFV in a dose-dependent manner. Based on truncated overlapping fragments of E2 and mutants, three linear neutralizing epitopes were identified highly conserved in various CSFV strains. Epitopes 8YRYAIS13 and 254HECLIG259 were reported for the first time. All the three epitopes are involved in virus internalization and attachment as shown in pre- or post-attachment neutralization. Recombinant polypeptides carrying epitopes successfully inhibit virus infection in PK-15 cells, indicating epitopes were located in receptor-binding domain (RBD). Further, both prophylactic and therapeutic functions of neutralizing antibody were evaluated in rabbits upon CSFV challenge, confirming the efficacy in vivo. These findings provide alternative antiviral strategies against CSFV and deepen the understanding in E2 function during virus entry.

A self-assembling nanoparticle: Implications for the development of thermostable vaccine candidates.

Effective controls on viral infections rely on the continuous development in vaccine technology. Nanoparticle (NP) antigens are highly immunogenic based on their unique physicochemical properties, making them molecular scaffolds to present soluble vaccine antigens. Here, viral targets (113-354 aas) were genetically fused to N terminal of mi3, a protein that self-assembles into nanoparticles composed of 60 subunits. With transmission electron microscopy, it was confirmed that target-mi3 fusion proteins which have insertions of up to 354 aas in N terminal form intact NPs. Moreover, viral targets are surface-displayed on NPs as indicated in dynamic light scattering. NPs exhibit perfect stability after long-term storage at room temperature. Moreover, SP-E2-mi3 NPs enhance antigen uptake and maturation in dendritic cells (DCs) via up-regulating marker molecules and immunostimulatory cytokines. Importantly, in a mouse model, SP-E2-mi3 nanovaccines against Classical swine fever virus (CSFV) remarkably improved CSFV-specific neutralizing antibodies (NAbs) and cellular immunity related cytokines (IFN-γ and IL-4) as compared to monomeric E2. Specially, improved NAb response with more than tenfold increase in NAb titer against both CSFV Shimen and HZ-08 strains indicated better cross-protection against different genotypes. Collectively, this structure-based, self-assembling NP provides an attractive platform to improve the potency of subunit vaccine for emerging pathogens.

Self-Assembling Nanovaccine Enhances Protective Efficacy Against CSFV in Pigs.

Classical swine fever virus (CSFV) is a highly contagious pathogen, which pose continuous threat to the swine industry. Though most attenuated vaccines are effective, they fail to serologically distinguish between infected and vaccinated animals, hindering CSFV eradication. Beneficially, nanoparticles (NPs)-based vaccines resemble natural viruses in size and antigen structure, and offer an alternative tool to circumvent these limitations. Using self-assembling NPs as multimerization platforms provides a safe and immunogenic tool against infectious diseases. This study presented a novel strategy to display CSFV E2 glycoprotein on the surface of genetically engineered self-assembling NPs. Eukaryotic E2-fused protein (SP-E2-mi3) could self-assemble into uniform NPs as indicated in transmission electron microscope (TEM) and dynamic light scattering (DLS). SP-E2-mi3 NPs showed high stability at room temperature. This NP-based immunization resulted in enhanced antigen uptake and up-regulated production of immunostimulatory cytokines in antigen presenting cells (APCs). Moreover, the protective efficacy of SP-E2-mi3 NPs was evaluated in pigs. SP-E2-mi3 NPs significantly improved both humoral and cellular immunity, especially as indicated by the elevated CSFV-specific IFN-γ cellular immunity and >10-fold neutralizing antibodies as compared to monomeric E2. These observations were consistent to in vivo protection against CSFV lethal virus challenge in prime-boost immunization schedule. Further results revealed single dose of 10 µg of SP-E2-mi3 NPs provided considerable clinical protection against lethal virus challenge. In conclusion, these findings demonstrated that this NP-based technology has potential to enhance the potency of subunit vaccine, paving ways for nanovaccine development.

Potency of nondepolarizing muscle relaxants on muscle-type acetylcholine receptors in denervated mouse skeletal muscle.

AIM: to investigate the changing resistance to nondepolarizing muscle relaxants (NDMRs) during the first month after denervation. METHODS: the denervated and innervated skeletal muscle cells were examined on days 1, 4, 7, 14, 21, and 28 after denervation. Individual denervated and innervated cells were prepared from the flexor digitorum brevis of the surgically denervated and contralateral hind feet, respectively. Nicotinic acetylcholine receptors (nAChRs) in the cells were activated with 30 micromol/L acetylcholine, either alone or in combination with various concentrations of vecuronium. Currents were recorded using a whole-cell patch-clamp technique. RESULTS: the concentrations of vecuronium resulting in half-maximal inhibitory responses (IC(50)) increased 1.2- (P>0.05), 1.7-, 3.7-, 2.5-, 1.9-, and 1.8-fold (P<0.05) at Days 1, 4, 7, 14, 21, and 28 after denervation, respectively, compared to the innervated control. Resistance to vecuronium appeared at Day 4, peaked at Day 7, and declined at Day 14 after denervation. Nevertheless, IC(50) values at Day 28 remained significantly higher than those for the innervated control, suggesting that the resistance to vecuronium had not disappeared at Day 28. CONCLUSION: The NDMR doses required to achieve satisfactory clinical effects differ at different times after muscle denervation.

Genetic characterization of a novel recombinant PRRSV2 from lineage 8, 1 and 3 in China with significant variation in replication efficiency and cytopathic effects.

There are four major porcine reproductive and respiratory syndrome virus 2 (PRRSV2) lineages circulating in China based on classification system, including lineages 1 (NADC30-like), 3 (QYYZ-like), 5.1 (VR2332-like) and 8 (JXA1-like/CH-1a-Like), which leads to the potential recombination. In the present study, a novel variant of PRRSV2 strain named JS18-3 was isolated from piglets suffering severe breathing difficulties in Jiangsu Province of China in 2018. Full-length genome analysis indicated that JS18-3 shared 86.5%, 87.9%, 84.2%, 82.2% and 86.4% nucleotide similarity with PRRSVs CH-1a, JXA1, VR2332, QYYZ and NADC30, respectively. 4871-6635 of JS18-3 shared the highest identity of 99.3% in nucleotide sequence with HP-PRRSV representative strain JXA1 indicating ongoing evolution to HP-PRRSV. JS18-3 was classified into classical lineage 8 of PRRSV2 based on phylogenetic analysis of complete genome and ORF5. Genomic break points in structural (ORF3) and non-structural (NSP2, NSP3) regions of genomes were detected in recombination analysis. JS18-3 is a recombinant isolate from lineages 8, 1 and 3. Replication enhancement and severe cytopathic effects caused by JS18-3 were observed in Marc-145 cells and porcine alveolar macrophages (PAMs) as compared to JX07, a typical strain of lineage 8. Pathogenicity results indicated that piglets inoculated with JS18-3 presented persistent fever, dyspnoea, serious microscopic lung lesions and lymph node congestion. The study suggests that lineage 8 of PRRSV2 is involved in continuing evolution by genetic recombination and mutation leading to outbreaks in vaccinated pigs in China.

CD163 Antibodies Inhibit PRRSV Infection via Receptor Blocking and Transcription Suppression.

CD163 has been identified as the essential receptor for Porcine reproductive and respiratory syndrome (PRRSV), a major etiologic agent of pigs. Scavenger receptor cysteine-rich domain 5-9 (SRCR5-9) in CD163 was shown to be responsible for the virus interaction. In this study, monoclonal antibodies (mAbs) 6E8 and 9A10 against SRCR5-9 were selected based on the significant activity to inhibit PRRSV infection in Porcine Alveolar Macrophage (PAMs) and Marc-145. Both mAbs are capable of blocking variable PRRSV strains in a dose-dependent manner. Meanwhile, as candidates for both prevention and therapeutics, the antibodies successfully inhibit PRRSV infection and the related NF-κB pathway either before or after virus attachment. Besides, the antibody treatment with either mAb leads to a remarkable decrease of CD163 transcription in PAMs and Marc-145. It is potentially caused by the excessive accumulation of membrane associated CD163 due to the failure in CD163 cleavage with the antibody binding. Further, conformational epitopes targeted by 6E8 and 9A10 are identified to be spanning residues 570SXDVGXV576 in SRCR5 and Q797 in SRCR7, respectively. CD163 with mutated epitopes expressed in 3D4 cells fails to support PRRSV infection while wild type CD163 recovers PRRSV infection, indicating the critical role of these residues in PRRSV invasion. These findings promote the understanding in the interaction between PRRSV and the receptor and provide novel broad antiviral strategies for PRRSV prevention and treatment via alternative mechanisms.

Efficacy Evaluation of Two Commercial Vaccines Against a Recombinant PRRSV2 Strain ZJnb16-2 From Lineage 8 and 3 in China.

From 2010, novel recombinant lineage 3 of porcine reproductive and respiratory syndrome virus 2 (PRRSV2) has continuously emerged China, which has brought about clinical outbreaks of the disease. Previously, a PRRSV2 strain named ZJnb16-2 was identified as a recombinant virus from lineage 8 and 3. In this study, two modified-live vaccines VR2332 MLV and HuN4-F112, which belong to lineage 5 and 8 respectively, were used for efficacy evaluation against the challenge of ZJnb16-2. Piglets vaccinated with HuN4-F112 exhibited temporary fever, higher average daily weight gain, and mild clinical signs as compared to VR2332 MLV vaccinated and unvaccinated piglets upon ZJnb16-2 challenge. Both vaccines could inhibit virus replication in piglets at 21days post challenge (DPC). Cross-reactivity of interferon (IFN)-γ secreting cells against ZJnb16-2 were detected in both vaccinated piglets. The number of IFN-γ secreting cells against ZJnb16-2 in the vaccination group exhibited sustaining elevation after challenge. Results demonstrated that both vaccines provided partial protection against ZJnb16-2 infection. A cross-neutralization antibody against ZJnb16-2 was not detected in any vaccinated piglet before challenge. A low neutralizing antibody titer against ZJnb16-2 was detected after challenge. Besides, all the vaccinated piglets suffered from different degrees of lung pathological lesions, indicating neither VR2332 MLV nor HuN4-F112 provided full protection against ZJnb16-2. This study provides valuable guidelines to control the recombinant virus from lineage 8 and 3 infection with MLV vaccines in the field.