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Chunyan Shao,1– 5,* Ziwei Yu,1– 5,* Tongwang Luo,1– 5,* Bin Zhou,1– 5 Quanjiang Song,1– 5 Zhuoyue Li,1– 5 Xiaoqiang Yu,1– 5 Sheng Jiang,1– 5 Yingshan Zhou,1– 5 Wanyu Dong,1– 5 Xingdong Zhou,1– 5 Xiaodu Wang,1– 5 Houhui Song1– 5 1Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Hangzhou, Zhejiang, 311300, People’s Republic of China; 2Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Hangzhou, Zhejiang, 311300, People’s Republic of China; 3Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, Hangzhou, Zhejiang, 311300, People’s Republic of China; 4China-Australia Joint Laboratory for Animal Health Big Data Analytics, Hangzhou, Zhejiang, 311300, People’s Republic of China; 5College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, People’s Republic of China*These authors contributed equally to this workCorrespondence: Houhui Song; Xiaodu Wang, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, People’s Republic of China, Tel +86 15064890670 ; +86 18806537583, Email songhh@zafu.edu.cn; xdwang@zafu.edu.cnIntroduction: Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly prevalent and endemic swine pathogen that causes significant economic losses to the global swine industry. Selenium nanoparticles (SeNPs) have attracted increasing attention in the biomedical field, given their antiviral effects. This study aimed to investigate the inhibitory effect of chitosan-coated SeNPs (CS-SeNPs) on PRRSV replication.Methods: In this study, CS-SeNPs were synthesized by chemical reduction and characterized by assessing the morphology, size distribution, zeta potential, and element composition. Marc-145 cells were infected with r-PRRSV-EGFP (0.1 MOI) and inoculated with CS-SeNPs (10 μM). Subsequently, the concentrations of hydrogen peroxide (H2O2) and glutathione (GSH), and glutathione peroxidase (GSH-Px) activity were measured using specific commercial assay kits. ORF5 RNA expression, viral titer, and nucleocapsid (N) protein expression were assessed using qRT-PCR, TCID50, and Western blot. ROS generation, apoptosis rates, and JNK /caspase-3/PARP protein expression were evaluated using dihydroethidium staining, flow cytometry, and Western blot.Results: The results showed that CS-SeNPs treatment significantly suppressed oxidative stress induced by r-PRRSV-EGFP infection by increasing GSH-Px activity, promoting GSH production, and inhibiting H2O2 synthesis. CS-SeNPs treatment significantly inhibited ORF5 gene expression, viral titers, and N protein of r-PRRSV-EGFP at 24 and 48 hours post-infection (hpi) in Marc-145 cells. The increase in apoptosis rates induced by r-PRRSV-EGFP infection was significantly decreased by CS-SeNPs inoculation through inhibiting ROS generation, JNK phosphorylation levels, and cleavage of caspase-3 and PARP mainly at 48 hpi.Conclusion: These results demonstrated that CS-SeNPs suppress PRRSV-induced apoptosis in Marc-145 cells via the ROS/JNK signaling pathway, thereby inhibiting PRRSV replication, which suggested the potential antiviral activity of CS-SeNPs that deserves further investigation for clinical applications.Keywords: chitosan-coated selenium nanoparticles, PRRSV, apoptosis, ROS, JNK signaling pathways

Porcine circovirus type 2 (PCV2) infection induces endoplasmic reticulum (ER) stress and oxidative stress. These cellular responses could be connected with apoptosis. However, the mechanisms that link ER stress and oxidative stress in PCV2-induced apoptosis are poorly characterized. Here, we demonstrate that PCV2 infection increased expression of proapoptotic protein C/EBP homologous protein (CHOP) and ER oxidoreductase 1 alpha (ERO1α). Inhibition of CHOP by RNA silencing or inhibition of ERO1α by short hairpin RNA or EN460 repressed PCV2-induced reactive oxygen species (ROS) generation, cytosolic calcium level, and apoptotic rate in PK-15 cells. Overexpression of ERO1α enhanced PCV2-induced oxidative stress, caspase-3 cleavage, and apoptosis rate. Treatment of PCV2-infected cells with ROS scavenger N-acetyl-L-cysteine downregulated PCV2-induced ROS production, cytosolic calcium level, and apoptosis rate, but intriguingly decreased expression of CHOP and ERO1α. Thus, we propose that PCV2 induces apoptosis through ER Stress via CHOP-ERO1α-ROS signaling in host cells.

COVID-19 pandemic caused by SARS-CoV-2 constitutes a global public health crisis with enormous economic consequences. Monoclonal antibodies against SARS-CoV-2 can provide an important treatment option to fight COVID-19, especially for the most vulnerable populations. In this work, potent antibodies binding to SARS-CoV-2 Spike protein were identified from COVID-19 convalescent patients. Among them, P4A1 interacts directly with and covers majority of the Receptor Binding Motif of the Spike Receptor-Binding Domain, shown by high-resolution complex structure analysis. We further demonstrate the binding and neutralizing activities of P4A1 against wild type and mutant Spike proteins or pseudoviruses. P4A1 was subsequently engineered to reduce the potential risk for Antibody-Dependent Enhancement of infection and to extend its half-life. The engineered antibody exhibits an optimized pharmacokinetic and safety profile, and it results in complete viral clearance in a rhesus monkey model of COVID-19 following a single injection. These data suggest its potential against SARS-CoV-2 related diseases.

Background Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly prevalent and endemic swine pathogen that can cause significant economic losses to the global swine industry. Host-targeted antiviral drugs have been developed as a new strategy for antiviral therapy. In this regard, selenium nanoparticles (SeNPs) have attracted increasing attention in the biomedical field, given their antiviral effects. The purpose of this study was to investigate whether chitosan-coated SeNPs (CS-SeNPs) could affect PRRSV replication in vitro. Methods In this study, CS-SeNPs were synthesized by chemical reduction and characterized by assessing the morphology, size distribution, zeta potential, and element composition. Marc-145 cells were infected with r-PRRSV-EGFP (0.1 MOI) and inoculated with CS-SeNPs (10 µM). Subsequently, the concentrations of hydrogen peroxide (H2O2) and glutathione (GSH), and glutathione peroxidase (GSH-Px) activity were measured using specific commercial assay kits. ORF5 RNA expression, viral titer, nucleocapsid (N) protein expression were assessed using qRT-PCR, TCID50, and Western blot. ROS generation, apoptosis rates, and JNK /caspase-3/PARP protein expression were evaluated using dihydroethidium staining, flow cytometry, and Western blot. Results The results showed that CS-SeNPs treatment significantly suppressed oxidative stress induced by r-PRRSV-EGFP infection by increasing GSH-Px activity, promoting GSH production, and inhibiting H2O2 synthesis. CS-SeNPs treatment significantly inhibited ORF5 gene expression, viral titers, and N protein of r-PRRSV-EGFP at 24 and 48 hours post-infection (hpi) in Marc-145 cells. The apoptosis rates initially increased by r-PRRSV-EGFP infection were significantly decreased by CS-SeNPs inoculation by inhibiting ROS generation, JNK phosphorylation levels, cleavage of caspase-3, and PARP mainly at 48 hpi. Conclusions Taken together, the present data demonstrated that CS-SeNPs synthesized by chemical reduction could enhance antioxidant capacity and effectively suppress PRRSV-induced apoptosis in Marc-145 cells via the ROS/JNK signaling pathway, thereby inhibiting PRRSV replication. This finding expands the treatment landscape for combating infections caused by PRRSV.

Single-chain variable fragment (scFv) is the most common format for phage display antibody library. The isolated scFvs need to be reformatted to full-length IgGs for further characterization. High throughput reformatting of scFv to IgG without disrupting VH-VL pairing is of great demanding for exhaustive screening of all antibodies in IgG format. Herein, we developed a strategy based on the overlap extension PCR in emulsion to reformat scFv to IgG while maintain the accuracy and complexity of variable region pairing. Using CD40 as an example target, we reformatted phage display derived CD40 binding scFv library to IgG mammalian display library and isolated high affinity CD40 binding IgGs. This robust and reliable antibody reformatting approach could be integrated into any phage display based antibody drug discovery.

The Coronavirus Disease of 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global public health and economy. Therapeutic options such as monoclonal antibodies (mAbs) against SARS-CoV-2 are in urgent need. We have identified potent monoclonal antibodies binding to SARS-CoV-2 Spike protein from COVID-19 convalescent patients and one of these antibodies, P4A1, interacts directly and covers the majority of the Receptor Binding Motif (RBM) of Spike receptor-binding domain (RBD), shown by high-resolution complex structure analysis. We further demonstrated P4A1 binding and neutralizing activities against wild type and mutant spike proteins. P4A1 was subsequently engineered to reduce the potential risk for antibody-dependent enhancement (ADE) of infection and to extend its half-life. The engineered mAb exhibits optimized pharmacokinetic and safety profile, and results in complete viral clearance in a rhesus monkey model of COVID-19 following a single injection.

The pandemic Coronavirus Disease 2019 (COVID-19) causes noticeable morbidity and mortality worldwide. In addition to vaccine and antiviral drug therapy, the use of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) neutralizing antibodies for treatment purposes is a viable alternative. In this study, we aimed to profile the humoral responses and identify neutralizing antibodies against SARS-CoV-2 using high-throughput single-cell sequencing that tailored to B cell receptor sequencing. From two convalescent patients with high serum titer against SARS-COV-2, we identified seven antibodies specifically binding to SARS-CoV-2. Among these, the most potent antibody, P4A1 was demonstrated to block the binding of spike protein to its receptor angiotensin-converting enzyme 2 (ACE2), and prevent the viral infection in neutralization assays with pseudovirus as well as live virus at nM to sub-nM range. Moreover, antibody P4A1 can also bind strongly to spike protein with N354D/D364Y, R408I, W436R, V367F or D614G mutations respectively, suggesting that the antibody alone or in combination with other antibodies that recognize different variations of SARS-CoV-2, may provide a broad spectrum therapeutic option for COVID-19 patients. Authors Lisu Huang, Bingqing Shen, Yu Guo, and Shu Shen contributed equally to this work.

Macroautophagy/autophagy is a conserved transport pathway where targeted structures are sequestered by phagophores, which mature into autophagosomes, and then delivered into lysosomes for degradation. Autophagy is involved in the pathophysiology of numerous diseases and its modulation is beneficial for the outcome of numerous specific diseases. Several lysosomal inhibitors such as bafilomycin A(1) (BafA(1)), protease inhibitors and chloroquine (CQ), have been used interchangeably to block autophagy in in vitro experiments assuming that they all primarily block lysosomal degradation. Among them, only CQ and its derivate hydroxychloroquine (HCQ) are FDA-approved drugs and are thus currently the principal compounds used in clinical trials aimed to treat tumors through autophagy inhibition. However, the precise mechanism of how CQ blocks autophagy remains to be firmly demonstrated. In this study, we focus on how CQ inhibits autophagy and directly compare its effects to those of BafA(1). We show that CQ mainly inhibits autophagy by impairing autophagosome fusion with lysosomes rather than by affecting the acidity and/or degradative activity of this organelle. Furthermore, CQ induces an autophagy-independent severe disorganization of the Golgi and endo-lysosomal systems, which might contribute to the fusion impairment. Strikingly, HCQ-treated mice also show a Golgi disorganization in kidney and intestinal tissues. Altogether, our data reveal that CQ and HCQ are not bona fide surrogates for other types of late stage lysosomal inhibitors for in vivo experiments. Moreover, the multiple cellular alterations caused by CQ and HCQ call for caution when interpreting results obtained by blocking autophagy with this drug.

Tauopathies include a variety of neurodegenerative diseases associated with the pathological aggregation of hyperphosphorylated tau, resulting in progressive cognitive decline and motor impairment. The underlying mechanism for motor deficits related to tauopathy is not yet fully understood. Here, we use a novel transgenic tau mouse line, Tau 58/4, with enhanced neuron-specific expression of P301S mutant tau to investigate the motor abnormalities in association with the peripheral nervous system. Using stationary beam, gait, and rotarod tests, motor deficits were found in Tau 58/4 mice already 3 months after birth, which deteriorated during aging. Hyperphosphorylated tau was detected in the cell bodies and axons of motor neurons. At the age of 9 and 12 months, significant denervation of the neuromuscular junction in the extensor digitorum longus muscle was observed in Tau 58/4 mice, compared to wild-type mice. Muscle hypotrophy was observed in Tau 58/4 mice at 9 and 12 months. Using electron microscopy, we observed ultrastructural changes in the sciatic nerve of 12-month-old Tau 58/4 mice indicative of the loss of large axonal fibers and hypomyelination (assessed by g-ratio). We conclude that the accumulated hyperphosphorylated tau in the axon terminals may induce dying-back axonal degeneration, myelin abnormalities, neuromuscular junction denervation, and muscular atrophy, which may be the mechanisms responsible for the deterioration of the motor function in Tau 58/4 mice. Tau 58/4 mice represent an interesting neuromuscular degeneration model, and the pathological mechanisms might be responsible for motor signs observed in some human tauopathies.

Objective Using the theory of sports biochemistry, we can better complete the formulation of the training plan, the evaluations of training effect and the athlete's fatigue status, the real-time monitoring of training intensity and training amount as well as the function level of athletes and the comprehensive evaluation of nutritional status. To provide some theoretical guidance for the daily training of Chinese hearing-impaired table tennis team and to gradually establish the biochemical monitoring model for the Chinese Deaf Table tennis team, this subject has applied biochemical index monitoring to this team. Methods 2.1 Research Object 8 Athletes (male 4 female 4) of the Chinese hearing-impaired table tennis team were studied. The average height, weight, and age were 174.3±5.1cm, 65.4±11.6kg, 23.5±4.9 years respectively.2.2 Research Methods 2.2.1 Literature To find out the energy-supplying and metabolic characteristics of table tennis as well as the modes to accelerate the recovery period of body fatigue, we have searched a variety of literature on this purpose. The investigation of athletes' nutrition regulation, physical training and rehabilitation and other related research results lays a good foundation for the implementation of the project. 2.2.2 Expert Interview This paper discusses the energy metabolism characteristics of the hearing-impaired table tennis players by discussing with the coaches, athletes and experts and scholars of the national Hearing Impairment project group. The evaluation index and standard of athlete's body function, the method of training load monitoring, the way of nutrition regulation, the means of fatigue recovery and the process of physical training were discussed. 3.2.3 Field Investigation From April, 20th, 2017 to July, 10th, 2017, two researchers have long been in the center of national table tennis training located at Zheng Ding, Hebei province, to complete training monitoring and research services. Results 3 Research Results Phlebotomizing 7 of the Chinese hearing-impaired table tennis players in June,2nd,2017 and June 7th, 2017 respectively, The blood samples were analyzed by the team of experts and researchers in the Sports Physiology and Biochemistry Laboratory in Beijing Sport University. Part of the results was shown below in table 1, table 2. (1) Training intensity monitoring Huang Mengping had a slightly higher creatine kinase, a slight decrease in testosterone, a slight rise in cortisol, a lower testosterone/cortisol value, as well as an insignificant reduction in body function than the previous time. She should focus on the recovery of her body condition after training. In general, the testosterone, cortisol and testosterone/cortisol level in this team is slightly higher than the last time, blood urea lower than the previous. Strengthening the monitoring of exercise and nutrition and continuing to maintain a high body synthesis ability are favorable to intense competition. The overall creatinine level decreased, whereas 4 members of the team had insignificantly high creatinine, especially for Huang Mengping who first had appeared high level of it. Although this condition was not too severe to focus on, we should strengthen the regulation of athlete muscle injury and protect their kidney functions. (2) Monitoring of endocrine system indicators Both males and females had higher testosterone synthesis capabilities. They should continue to take the nutritional supplements. The T/C ratio of Tian Jiping has escalated sharply, but it was lower than that of other players. We should pay attention to his training load and promote the recovery training. (3) Monitoring of Iron Metabolic Index Huang Mengping's hemoglobin value and RBC value have been slightly elevated this time. It is suggested that she should keep on to take nutritional supplements and strengthen aerobic endurance training. Hemoglobin for Wang Zhe and Lin Huan (slightly decreased this time) was higher than their counterparts. The ability to transport oxygen was excellent, and it is agreeable to keep on. They need to continue to maintain and promote the body's oxygen reserve capacity. At the same time, they can also upgrade their overall red blood cell levels. Men have seen a high level of hemoglobin and the number of red blood cells as well as robust capabilities of oxymoron reservation and transportation. It is recommended to enhance aerobic endurance training, mainly improving the aerobic capacity. The serum iron of Tian Jiping was promoted quickly. He needs to build up the amount of iron nutrient intake and support the body synthesis. The full iron metabolic indicators were normal, but Zhang Chaoyue and Lin Lin Huan have been seen the lack of the abilities to synthesis iron. So we need to pay attention to iron metabolism-related nutrition intake. In general, iron protein level and the capability to reserve iron have declined. It is recommended to take more iron nutrients, Especially for Shi Ce. (4) Food surveillance After the diet regulation, the indicators for the team's blood fat were within the normal range. Zhang Chaoyue and Wang Zhe should control the high-fat food intake, thus reducing the amount of low-density lipoprotein. (5) Surveillance of immune Indicators The white cell, blood cell classification and immunoglobulin (IgG, IgM, IgA) of the team are all normal, Wang Zhe’s immunoglobulin A and Xu You’s immunoglobulin M are slightly low, we should pay attention to protection. Conclusions Through the overall monitoring and analysis of the biochemical indexes of the leading athletes of Chinese hearing-impaired table tennis team, The characteristics of biochemical indexes of the high-level hearing-impaired table tennis players are mastered. On the basis of the overall characteristics of the individual, we carried out personalized monitoring and evaluation to give coaches and athletes advice on training, rehabilitation and other aspects related to practice. Biochemical tracking in China's hearing-impaired table tennis team has achieved an excellent application results that have been unanimously recognized by the coaches and athletes.

Autophagy-related (ATG) proteins regulate autophagy, but recent work indicates that some also have autophagy-independent roles. Here, Mauthe et al. perform an unbiased siRNA screen to examine the effects of ATG protein depletion on viral replication and demonstrate autophagy-independent functions for ATG13 and FIP200 in the picornaviral life cycle., Autophagy is a catabolic process regulated by the orchestrated action of the autophagy-related (ATG) proteins. Recent work indicates that some of the ATG proteins also have autophagy-independent roles. Using an unbiased siRNA screen approach, we explored the extent of these unconventional functions of ATG proteins. We determined the effects of the depletion of each ATG proteome component on the replication of six different viruses. Our screen reveals that up to 36% of the ATG proteins significantly alter the replication of at least one virus in an unconventional fashion. Detailed analysis of two candidates revealed an undocumented role for ATG13 and FIP200 in picornavirus replication that is independent of their function in autophagy as part of the ULK complex. The high numbers of unveiled ATG gene-specific and pathogen-specific functions of the ATG proteins calls for caution in the interpretation of data, which rely solely on the depletion of a single ATG protein to specifically ablate autophagy.

Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus released into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells., Highlights • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs.

The porcine epidemic diarrhea virus (PEDV) is a coronavirus (CoV) belonging to the alpha-CoV genus and it causes high mortality in infected sucking piglets, resulting in substantial losses in the farming industry. CoV trigger a drastic reorganization of host cell membranes to promote their replication and egression, but a detailed description of the intracellular remodeling induced by PEDV is still missing. In this study, we examined qualitatively and quantitatively, using electron microscopy, the intracellular membrane reorganization induced by PEDV over the course of an infection. With our ultrastructural approach, we reveal that, as most of CoV, PEDV initially forms double-membrane vesicles (DMVs) and convoluted membranes (CMs), which probably serve as replication/transcription platforms. Interestingly, we also found that viral particles start to form almost simultaneously in both the endoplasmic reticulum and the large virion-containing vacuoles (LVCVs), which are compartments originating from the Golgi, confirming that alpha-CoV assemble indistinguishably in two different organelles of the secretory pathway. Moreover, PEDV virons appear to have an immature and a mature form, similar to another alpha-CoV the transmissible gastroenteritis coronavirus (TGEV). Altogether, our study underlies the similarities and differences between the lifecycle of alpha-CoV and that of viruses belonging to other CoV subfamilies.