Radix Isatidis polysaccharide (RIP) resists the infection of QX-type infectious bronchitis virus via the MDA5/TLR3/IRF7 signaling pathway.

Although vaccines play a major role in the prevention of infectious bronchitis (IB), Anti-IB drugs still have great potential in poultry production. Radix Isatidis polysaccharide (RIP) is a crude extract of Banlangen with antioxidant, antibacterial, antiviral, and multiple immunomodulatory functions. The aim of this study was to explore the innate immune mechanisms responsible for RIP-mediated alleviation of infectious bronchitis virus (IBV)-induced kidney lesions in chickens. Specific-pathogen-free (SPF) chicken and chicken embryo kidney (CEK) cells cultures were pretreated with RIP and then infected with the QX-type IBV strain, Sczy3. Morbidity, mortality, and tissue mean lesion scores were calculated for IBV-infected chickens, and the viral loads, inflammatory factor gene mRNA expression levels, and innate immune pathway gene mRNA expression levels in infected chickens and CEK cell cultures were determined. The results show that RIP could alleviate IBV-induced kidney damage, decrease CEK cells susceptibility to IBV infection, and reduce viral loads. Additionally, RIP reduced the mRNA expression levels of the inflammatory factors IL-6, IL-8, and IL-1ß by decreasing the mRNA expression level of NF-κB. Conversely, the expression levels of MDA5, TLR3, STING, Myd88, IRF7, and IFN-ß were increased, indicating that RIP conferred resistance to QX-type IBV infection via the MDA5, TLR3, IRF7 signaling pathway. These results provide a reference for both further research into the antiviral mechanisms of RIP and the development of preventative and therapeutic drugs for IB.

The conserved L1089 in the S2 subunit of avian infectious bronchitis virus determines viral kidney tropism by disrupting virus-cell fusion.

The virulence of avian gamma-coronavirus infectious bronchitis viruses (IBV) for the kidney has led to high mortality in dominant-genotype isolations, but the key sites of viral protein that determine kidney tropism are still not fully clear. In this study, the amino acid sequences of the S2 subunit of IBVs with opposing adaptivity to chicken embryonic kidney cells (CEKs) were aligned to identify putative sites associated with differences in viral adaptability. The S2 gene and the putative sites of the non-adapted CN strain were introduced into the CEKs-adapted SczyC30 strain to rescue seven mutants. Analysis of growth characteristics showed that the replacement of the entire S2 subunit and the L1089I substitution in the S2 subunit entirely abolished the proliferation of recombinant IBV in CEKs as well as in primary chicken oviduct epithelial cells. Pathogenicity assays also support the decisive role of this L1089 for viral nephrotropism, and this non-nephrotropic L1089I substitution significantly attenuates pathogenicity. Analysis of the putative cause of proliferation inhibition in CEKs suggests that the L1089I substitution affects neither virus attachment nor endocytosis, but instead fails to form double-membrane vesicles to initiate the viral replication and translation. Position 1089 of the IBV S2 subunit is conservative and predicted to lie in heptad repeat 2 domains. It is therefore reasonable to conclude that the L1089I substitution alters the nephrotropism of parent strain by affecting virus-cell fusion. These findings provide crucial insights into the adaptive mechanisms of IBV and have applications in the development of vaccines and drugs against IB.

Multiple Death Pathways of Neutrophils Regulate Alveolar Macrophage Proliferation.

Alveolar macrophage (AM) proliferation and self-renewal play an important role in the lung tissue microenvironment. However, the impact of immune cells, especially the neutrophils, on AM homeostasis or function is not well characterized. In this study, we induced in vivo migration of neutrophils into bronchoalveolar lavage (BAL) fluid and lung using CXCL1, and then co-cultured these with AMs in vitro. Neutrophils in the BAL (BAL-neutrophils), rather than neutrophils of bone marrow (BM-neutrophils), were found to inhibit AM proliferation. Analysis of publicly available data showed high heterogeneity of lung neutrophils with distinct molecular signatures of BM- and blood-neutrophils. Unexpectedly, BAL-neutrophils from influenza virus PR8-infected mice (PR8-neutrophils) did not inhibit the proliferation of AMs. Bulk RNA sequencing further revealed that co-culture of AMs with PR8-neutrophils induced IFN-α and -γ responses and inflammatory response, and AMs co-cultured with BAL-neutrophils showed higher expression of metabolism- and ROS-associated genes; in addition, BAL-neutrophils from PR8-infected mice modulated AM polarization and phagocytosis. BAL-neutrophil-mediated suppression of AM proliferation was abrogated by a combination of inhibitors of different neutrophil death pathways. Collectively, our findings suggest that multiple cell death pathways of neutrophils regulate the proliferation of AMs. Targeting neutrophil death may represent a potential therapeutic strategy for improving AM homeostasis during respiratory diseases.

The N1038S Substitution and 1153EQTRPKKSV1162 Deletion of the S2 Subunit of QX-Type Avian Infectious Bronchitis Virus Can Synergistically Enhance Viral Proliferation.

The S2 subunit of infectious bronchitis virus (IBV) plays a critical role in the process of IBV infection. A comparison between the S2 subunit sequence of chicken embryo kidney cell (CEK) adapted virulent QX-like IBV strain SczyC30 (hereafter referred to as zy30) and its CEK-attenuated strain, SczyC100, revealed an N1038S substitution in S2 subunit and a 1154EQTRPKKSV1162 residue deletion in the C-terminus of the S2 subunit. In order to explore whether these two mutations are related to changes in the biological characteristics of IBV, we firstly constructed an infectious clone of zy30 using a bacterial artificial chromosome (BAC), which combines the transcription of infectious IBV genomic RNA in non-susceptible BHK-21 cells with the amplification of rescued virus rzy30 in CEK cells. Then, three recombinant viruses, including an rzy30S2-N1038S strain that contained the N1038S substitution, an rzy30S2-CT9△ strain that contained the 1154EQTRPKKSV1162 deletion, and an rzy30S2-N1038S-CT9△ strain that contained both mutations, were constructed using rescued virus rzy30 as the backbone. The results showed that each mutation did not significantly affect the replication titer in CEK cells but reduced pathogenicity in chickens, while in combination, the N1038S substitution and 1154EQTRPKKSV1162 deletion improved the proliferation efficiency in CEK cells and reduced pathogenicity, compared to rzy30 strain. The contribution made by the 1154EQTRPKKSV1162 deletion in reducing pathogenicity was higher than that of N1038S substitution. Our results revealed that the N1038S substitution and 1154EQTRPKKSV1162 deletion in S2 subunit were deeply involved in the replication efficiency of IBV and contributed to reduction of viral pathogenicity.

Association Between Metabolic Syndrome and Mild Parkinsonian Signs Progression in the Elderly.

Background: This study investigated the impact of metabolic syndrome on the progression from mild parkinsonian signs (MPS) to Parkinson's disease (PD). Methods: A total of 1,563 participants with MPS completed 6 years of follow-up. The diagnosis of metabolic syndrome was made according to Adult Treatment Panel III of the National Cholesterol Education Program. The evaluations of MPS and PD were based on the motor portion of the Unified Parkinson's Disease Rating Scale. Cox proportional hazard models were used to identify the association between metabolic syndrome and PD conversion. Results: Of the 1,563 participants, 482 (30.8%) with MPS developed PD at the end of the follow-up. Metabolic syndrome (HR: 1.69, 95% CI: 1.29-2.03) was associated with the risk of PD conversion. Metabolic syndrome was associated with the progression of bradykinesia (HR: 1.85, 95% CI: 1.43-2.34), rigidity (HR: 1.36, 95% CI: 1.19-1.57), tremor (HR: 1.98, 95% CI: 1.73-2.32), and gait/balance impairment (HR: 1.66, 95% CI: 1.25-2.11). The effect of metabolic syndrome on the progression of bradykinesia and tremor was nearly two fold. Participants treated for two or three to four components of metabolic syndrome, including high blood pressure, high fasting plasma glucose, hypertriglyceridemia, and low HDL-C, had a lower risk of PD conversion. Conclusion: Metabolic syndrome increased the risk of progression from MPS to PD. Participants treated for two or more components of metabolic syndrome had a lower risk of PD conversion.

Efficacy and safety of current therapeutic options for COVID-19 - lessons to be learnt from SARS and MERS epidemic: A systematic review and meta-analysis.

The rapidly progressing of coronavirus disease 2019 (COVID-19) pandemic has become a global concern. This meta-analysis aimed at evaluating the efficacy and safety of current option of therapies for severe acute respiratory syndrome (SARS), Middle Eastern respiratory syndrome (MERS) besides COVID-19, in an attempt to identify promising therapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. We searched PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and WANFANG DATA for randomized controlled trials (RCTs), prospective cohort, and retrospective cohort studies that evaluated therapies (hydroxychloroquine, lopinavir/ritonavir-based therapy, and ribavirin-based therapy, etc.) for SARS, MERS, and COVID-19. The primary outcomes were mortality, virological eradication and clinical improvement, and secondary outcomes were improvement of symptoms and chest radiography results, incidence of acute respiratory disease syndrome (ARDS), utilization of mechanical ventilation, and adverse events (AEs). Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models, and the quality of evidence was appraised using GRADEpro. Eighteen articles (5 RCTs, 2 prospective cohort studies, and 11 retrospective cohort studies) involving 4,941 patients were included. Compared with control treatment, anti-coronary virus interventions significantly reduced mortality (RR 0.65, 95% CI 0.44-0.96; I2 = 81.3%), remarkably ameliorate clinical improvement (RR 1.52, 95% CI 1.05-2.19) and radiographical improvement (RR 1.62, 95% CI 1.11-2.36, I2 = 11.0 %), without manifesting clear effect on virological eradication, incidence of ARDS, intubation, and AEs. Subgroup analyses demonstrated that the combination of ribavirin and corticosteroids remarkably decreased mortality (RR 0.43, 95% CI 0.27-0.68). The lopinavir/ritonavir-based combination showed superior virological eradication and radiographical improvement with reduced rate of ARDS. Likewise, hydroxychloroquine improved radiographical result. For safety, ribavirin could induce more bradycardia, anemia and transaminitis. Meanwhile, hydroxychloroquine could increase AEs rate especially diarrhea. Overall, the quality of evidence on most outcomes were very low. In conclusion, although we could not draw a clear conclusion for the recommendation of potential therapies for COVID-19 considering the very low quality of evidence and wide heterogeneity of interventions and indications, our results may help clinicians to comprehensively understand the advantages and drawbacks of each anti-coronavirus agents on efficacy and safety profiles. Lopinavir/ritonavir combinations might observe better virological eradication capability than other anti-coronavirus agents. Conversely, ribavirin might cause more safety concerns especially bradycardia. Thus, large RCTs objectively assessing the efficacy of antiviral therapies for SARS-CoV-2 infections should be conducted with high priority.

Temporary vaccination clinic for COVID-19 in Zhuhai, China.

Vaccines are urgently needed to control the COVID-19 pandemic. To gradually increase the vaccination rate among residents, temporary vaccination clinic for COVID-19 plays an important role. It should be located in an area with convenient transportation and concentrated population. Functional zones including waiting and inquiry, registration and notification, injection, observation and emergency room should be established. All vaccine recipients' information should be uploaded to the national immunization information system. Medical staff at the temporary vaccination clinic should be professionally trained. A cautious disinfection and wiping are essential for the temporary vaccination clinic.

PTP-MEG2 regulates quantal size and fusion pore opening through two distinct structural bases and substrates.

Tyrosine phosphorylation of secretion machinery proteins is a crucial regulatory mechanism for exocytosis. However, the participation of protein tyrosine phosphatases (PTPs) in different exocytosis stages has not been defined. Here we demonstrate that PTP-MEG2 controls multiple steps of catecholamine secretion. Biochemical and crystallographic analyses reveal key residues that govern the interaction between PTP-MEG2 and its substrate, a peptide containing the phosphorylated NSF-pY83 site, specify PTP-MEG2 substrate selectivity, and modulate the fusion of catecholamine-containing vesicles. Unexpectedly, delineation of PTP-MEG2 mutants along with the NSF binding interface reveals that PTP-MEG2 controls the fusion pore opening through NSF independent mechanisms. Utilizing bioinformatics search and biochemical and electrochemical screening approaches, we uncover that PTP-MEG2 regulates the opening and extension of the fusion pore by dephosphorylating the DYNAMIN2-pY125 and MUNC18-1-pY145 sites. Further structural and biochemical analyses confirmed the interaction of PTP-MEG2 with MUNC18-1-pY145 or DYNAMIN2-pY125 through a distinct structural basis compared with that of the NSF-pY83 site. Our studies thus provide mechanistic insights in complex exocytosis processes.

COVID-19 emergencies around the globe: China's experience in controlling COVID-19 and lessons learned.

MOTIVATION: Nations around the world have been significantly impacted during the COVID-19 pandemic. China's strategies for controlling COVID-19 offer valuable lessons for the global community. By learning from China's experience and lessons, other countries could also find appropriate methods to control the pandemic. PROBLEM STATEMENT: What measures has China taken to control the pandemic? What lessons has China learned through this pandemic? APPROACH/METHODS: The literature on China's lessons and experience in controlling the COVID-19 pandemic was searched and reviewed. Related newspapers and magazines were also searched. RESULTS: China's experience can be summed up as establishing temporary hospitals, strict isolation, experts with a knowledge of COVID-19, and measures that increase social distancing. CONCLUSIONS: By learning from the experience of China, other countries in the world could eventually find the methods to control the COVID-19 pandemic. An emergency response system should be established in each country. Doctors and nurses are not alone in fighting COVID-19, and the entire world is helping them. With cooperation, current difficulties could be overcome.

Current therapeutic options for coronavirus disease 2019 (COVID-19)-lessons learned from severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) therapy: a systematic review protocol.

BACKGROUND: Coronavirus disease 2019 (COVID-19), also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, first manifested in December 2019, and spread rapidly worldwide. Facing this lethal disease, there is an urgent need to develop potent therapies against SARS-CoV-2 infection. SARS-CoV-2 phylogenetically and symptomatically resembles SARS-CoV and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Numerous agents have been utilised during the severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) epidemics, which may show some benefit against SARS-CoV-2. METHODS: MEDLINE, EMBASE, Cochrane Library, CBM Disc, China National Knowledge Infrastructure, Wanfang Data, and the China Science and Technology Journal Database will be searched. Manual searches will be conducted by searching pre-printing websites, clinical trial registers, and screening the reference lists of inclusive studies. The screening of all citations and the selection of inclusive articles will be conducted by two reviewers. Randomised controlled trials (RCTs) and controlled cohort studies reporting antiviral therapies, including ribavirin, remdesivir, lopinavir/ritonavir, arbidol, chloroquine, hydroxychloroquine, and interferon, for SARS, MERS, and COVID-19 will be included. The primary outcomes will be mortality, incidence of acute respiratory distress syndrome, and utilisation of mechanical ventilation and intensive care unit admission. The secondary outcomes will be improvement in symptoms and chest radiography results, virus clearance, changes in blood test results, and serum tests. The quality of the retrieved RCTs and observational studies will be appraised according to the Cochrane risk of bias tool and the Newcastle-Ottawa Scale, respectively. If feasible, we will perform a fixed- or random-effects meta-analysis. DISCUSSION: This systematic review and meta-analysis will summarise all the available evidence for the efficacy and safety of current therapeutic options in SARS-CoV, MERS-CoV, or SARS-CoV-2-infected patients. The findings of this study may inform subsequent antiviral interventions for patients with COVID-19. STUDY REGISTRATION: The protocol of this study has been submitted to the PROSPERO platform (https://www.crd.york.ac.uk/PROSPERO/), and the registration number is CRD42020168639.

Correlation between gastrointestinal symptoms and disease severity in patients with COVID-19: a systematic review and meta-analysis.

OBJECTIVE: To study the correlation between gastrointestinal (GI) symptoms and disease severity in patients with COVID-19. DESIGN: We searched six databases including three Chinese and three English databases for all the published articles on COVID-19. Studies were screened according to inclusion and exclusion criteria. The relevant data were extracted and all the statistical analyses were performed using Revman5.3. RESULT: In a meta-analysis of 9 studies, comprising 3022 patients, 479 patients (13.7%, 95% CI 0.125 to 0.149) had severe disease and 624 patients (14.7%, 95% CI 0.136 to 0.159) had GI symptoms. Of 624 patients with GI symptoms, 118 patients had severe disease (20.5%, 95% CI 0.133 to 0.276) and of 2397 cases without GI symptoms, 361 patients had severe disease (18.2%, 95% CI 0.129 to 0.235). Comparing disease severity of patients with and without GI symptoms, the results indicated: I²=62%, OR=1.21, 95% CI 0.94 to 1.56, p=0.13; there was no statistically significant difference between the two groups. The funnel plot was symmetrical with no publication bias. CONCLUSION: Current results are not sufficient to demonstrate a significant correlation between GI symptoms and disease severity in patients with COVID-19.

Complex emergencies of COVID-19: management and experience in Zhuhai, China.

The impact of communicable diseases (infectious diseases) on human health is obvious. The sudden outbreak of COVID-19 (Corona Virus Disease 2019) has made people realise the threat of communicable diseases to mankind. As a city of many migrants, Zhuhai Special Economic Zone experienced great challenges brought about by the COVID-19 epidemic. Experience has been acquired from all aspects of this. A highly reactive, multifunctional and efficient emergency management system should be established, and the significance of information communication should be fully understood for the future.