Huanchun Chen

Bio: Huanchun Chen is an academic researcher from Huazhong Agricultural University. The author has contributed to research in topics: Virus & Virulence. The author has an hindex of 53, co-authored 613 publications receiving 12768 citations. Previous affiliations of Huanchun Chen include Chinese Ministry of Agriculture & Wuhan Polytechnic University.

A serological survey of SARS-CoV-2 in cat in Wuhan.

Abstract: COVID-19 is a new respiratory illness caused by SARS-CoV-2, and has constituted a global public health emergency. Cat is susceptible to SARS-CoV-2. However, the prevalence of SARS-CoV-2 in cats remains largely unknown. Here, we investigated the infection of SARS-CoV-2 in cats during COVID-19 outbreak in Wuhan by serological detection methods. A cohort of serum samples were collected from cats in Wuhan, including 102 sampled after COVID-19 outbreak, and 39 prior to the outbreak. Fifteen sera collected after the outbreak were positive for the receptor binding domain (RBD) of SARS-CoV-2 by indirect enzyme linked immunosorbent assay (ELISA). Among them, 11 had SARS-CoV-2 neutralizing antibodies with a titer ranging from 1/20 to 1/1080. No serological cross-reactivity was detected between SARS-CoV-2 and type I or II feline infectious peritonitis virus (FIPV). In addition, we continuously monitored serum antibody dynamics of two positive cats every 10 days over 130 days. Their serum antibodies reached the peak at 10 days after first sampling, and declined to the limit of detection within 110 days. Our data demonstrated that SARS-CoV-2 has infected cats in Wuhan during the outbreak and described serum antibody dynamics in cats, providing an important reference for clinical treatment and prevention of COVID-19.

The Leader Proteinase of Foot-and-Mouth Disease Virus Negatively Regulates the Type I Interferon Pathway by Acting as a Viral Deubiquitinase

Abstract: The leader proteinase (L pro ) of foot-and-mouth disease virus (FMDV) is a papain-like proteinase that plays an important role in FMDV pathogenesis. Previously, it has been shown that L pro is involved in the inhibition of the type I interferon (IFN) response by FMDV. However, the underlying mechanisms remain unclear. Here we demonstrate that FMDV Lb pro , a shorter form of L pro , has deubiquitinating activity. Sequence alignment and structural bioinformatics analyses revealed that the catalytic residues (Cys51 and His148) are highly conserved in FMDV Lb pro of all seven serotypes and that the topology of FMDV Lb pro is remarkably similar to that of ubiquitin-specific protease 14 (USP14), a cellular deubiquitylation enzyme (DUB), and to that of severe acute respiratory syndrome coronavirus (SARS-CoV) papain-like protease (PLpro), a coronaviral DUB. Both purified Lb pro protein and in vivo ectopically expressed Lb pro removed ubiquitin (Ub) moieties from cellular substrates, acting on both lysine-48- and lysine-63-linked polyubiquitin chains. Furthermore, Lb pro significantly inhibited ubiquitination of retinoic acid-inducible gene I (RIG-I), TANK-binding kinase 1 (TBK1), TNF receptor-associated factor 6 (TRAF6), and TRAF3, key signaling molecules in activation of type I IFN response. Mutations in Lb pro that ablate the catalytic activity (C51A or D163N/D164N) or disrupt the SAP (for SAF-A/B, Acinus, and PIAS) domain (I83A/L86A) abrogated the DUB activity of Lb pro as well as its ability to block signaling to the IFN- promoter. Collectively, these results demonstrate that FMDV Lb pro

Isolation, Antimicrobial Resistance, and Virulence Genes of Pasteurella multocida Strains from Swine in China

Abstract: A total of 233 isolates of Pasteurella multocida were obtained from 2,912 cases of clinical respiratory disease in pigs in China, giving an isolation rate of 8.0%. Serogroup A P. multocida isolates were isolated from 92 cases (39.5%), and serogroup D isolates were isolated from 128 cases (54.9%); 12 isolates (5.2%) were untypeable. P. multocida was the fourth most frequent pathogenic bacterium recovered from the respiratory tract, after Streptococcus suis, Haemophilus parasuis, and Escherichia coli. All isolates were characterized for their susceptibilities to 20 antibiotics and the presence of 19 genes for virulence factors (VFs). The frequency of antimicrobial resistance among P. multocida isolates from swine in China was higher than that reported among P. multocida isolates from swine in from other countries, and 93.1% of the isolates showed multiple-drug resistance. There was a progressive increase in the rate of multiresistance to more than seven antibiotics, from 16.2% in 2003 to 62.8% in 2007. The resistance profiles suggested that cephalosporins, florfenicol, and fluoroquinolones were the drugs most likely to be active against P. multocida. Use of PCR showed that colonization factors (ptfA, fimA, and hsf-2), iron acquisition factors, sialidases (nanH), and outer membrane proteins occurred in most porcine strains. The VFs pfhA, tadD, toxA, and pmHAS were each present in <50% of strains. The various VFs exhibited distinctive associations with serogroups: concentrated in serogroup A, concentrated in serogroup D, or occurring jointly in serogroups A and D. These findings provide novel insights into the epidemiological characteristics of porcine P. multocida isolates and suggest that the potential threat of such multiresistant bacteria in food-producing animals should not be neglected.

Porcine Epidemic Diarrhea Virus Nucleocapsid Protein Antagonizes Beta Interferon Production by Sequestering the Interaction between IRF3 and TBK1

Abstract: Porcine epidemic diarrhea virus (PEDV), a porcine enteropathogenic coronavirus, causes lethal watery diarrhea in piglets and results in large economic losses in many Asian and European countries A large-scale outbreak of porcine epidemic diarrhea occurred in China in 2010, and the virus emerged in the United States in 2013 and spread rapidly, posing significant economic and public health concerns Previous studies have shown that PEDV infection inhibits the synthesis of type I interferon (IFN), and viral papain-like protease 2 has been identified as an IFN antagonist In this study, we found that the PEDV-encoded nucleocapsid (N) protein also inhibits Sendai virus-induced IFN-β production, IFN-stimulated gene expression, and activation of the transcription factors IFN regulatory factor 3 (IRF3) and NF-κB We also found that N protein significantly impedes the activation of the IFN-β promoter stimulated by TBK1 or its upstream molecules (RIG-I, MDA5, IPS-1, and TRAF3) but does not counteract its activation by IRF3 A detailed analysis revealed that the PEDV N protein targets TBK1 by direct interaction and that this binding sequesters the association between TBK1 and IRF3, which in turn inhibits both IRF3 activation and type I IFN production Together, our findings demonstrate a new mechanism evolved by PEDV to circumvent the host9s antiviral immunity IMPORTANCE PEDV has received increasing attention since the emergence of a PEDV variant in China and the United States Here, we identify nucleocapsid (N) protein as a novel PEDV-encoded interferon (IFN) antagonist and demonstrate that N protein antagonizes IFN production by sequestering the interaction between IRF3 and TBK1, a critical step in type I IFN signaling This adds another layer of complexity to the immune evasion strategies evolved by this economically important viral pathogen An understanding of its immune evasion mechanism may direct us to novel therapeutic targets and more effective vaccines against PEDV infection

SPAdes, a new genome assembly algorithm and its applications to single-cell sequencing ( 7th Annual SFAF Meeting, 2012)

Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

Abstract: Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Characteristics of SARS-CoV-2 and COVID-19

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease, named ‘coronavirus disease 2019’ (COVID-19), which threatens human health and public safety. In this Review, we describe the basic virology of SARS-CoV-2, including genomic characteristics and receptor use, highlighting its key difference from previously known coronaviruses. We summarize current knowledge of clinical, epidemiological and pathological features of COVID-19, as well as recent progress in animal models and antiviral treatment approaches for SARS-CoV-2 infection. We also discuss the potential wildlife hosts and zoonotic origin of this emerging virus in detail. In this Review, Shi and colleagues summarize the exceptional amount of research that has characterized acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) since this virus has swept around the globe. They discuss what we know so far about the emergence and virology of SARS-CoV-2 and the pathogenesis and treatment of COVID-19.