Porcine epidemic diarrhea virus (PEDV) is an intestinal coronavirus that can cause porcine epidemic diarrhea, leading to diarrhea, vomiting, weight loss, and even death in piglets. Due to the diversity of PEDV strains, traditional vaccines are difficult to sustainably and effectively prevent and control PEDV. This article reviews the strategies and mechanisms of active substances in regulating intracellular signaling pathways, viral proteins, and microbial metabolites to enhance the host immune function against PEDV. It emphasizes the prevention of PEDV resistance and the potential harm of PEDV breaking through interspecies barriers to the human society, aiming to provide reliable theoretical support for the development of new antiviral drugs or vaccines.
Porcine epidemic diarrhea virus/immunology* ; Animals ; Swine ; Swine Diseases/prevention & control* ; Antiviral Agents/pharmacology* ; Coronavirus Infections/virology* ; Viral Vaccines/immunology* ; Humans ; Signal Transduction

This study aims to establish an antibody detection method for porcine deltacoronavirus (PDCoV). The recombinant proteins PDCoV-N1 and PDCoV-N2 were expressed via the prokaryotic plasmid pColdII harboring the N gene sequence of the PDCoV strain CH/XJYN/2016. The reactivity and specificity of PDCoV-N1 and PDCoV-N2 with anti-PEDV sera were analyzed after the recombinant proteins were analyzed by SDS-PAGE and purified by the Ni-NTA Superflow Cartridge. Meanwhile, Western blotting and indirect immunofluorescence assay were carried out separately to validate the recombinant proteins PDCoV-N1 and PDCoV-N2. Finally, we established an indirect ELISA method based on the recombinant protein PDCoV-N2 after optimizing the conditions and tested the sensitivity, specificity, and reproducibility of the method. Then, the established method was employed to examine 102 clinical serum samples. The recombinant protein PDCoV-N2 showed low cross-reactivity with anti-PEDV sera. The optimal conditions of the indirect ELISA method based on PDCoV-N2 were as follows: the antigen coating concentration of 1.25 μg/mL and coating at 37 ℃ for 1 h; blocking by BSA overnight at 4 ℃; serum sample dilution at 1:50 and incubation at 37 ℃ for 1 h; secondary antibody dilution at 1:80 000 and incubation at 37 ℃ for 1 h; color development with TMB chromogenic solution at 37 ℃ for 10 min. The S/P value ≥ 0.45, ≤0.38, and between 0.45 and 0.38 indicated that the test sample was positive, negative, and suspicious, respectively. The testing results of the antisera against porcine epidemic diarrhea virus (PEDV), porcine circovirus 2 (PCV2), transmissible gastroenteritis virus (TGEV), foot-and-mouth disease virus (FMDV), and African swine fever virus (ASFV) showed that the S/P values were all less than 0.38. The testing results of the 800-fold diluted anti-PDCoV sera were still positive. The results of the inter- and intra-batch tests showed that the coefficients of variation of this method were less than 10%. Clinical serum sample test results showed the coincidence rate between this method and neutralization test was 94.12%. In this study, an ELISA method for the detection of anti-PDCoV antibodies was successfully established based on the truncated N protein of PDCoV. This method is sensitive, specific, stable, and reproducible, serving as a new method for the clinical diagnosis of PDCoV.
Animals ; Enzyme-Linked Immunosorbent Assay/methods* ; Swine ; Antibodies, Viral/blood* ; Recombinant Proteins/genetics* ; Deltacoronavirus/isolation & purification* ; Coronavirus Infections/virology* ; Swine Diseases/diagnosis* ; Coronavirus Nucleocapsid Proteins ; Sensitivity and Specificity

Coronaviruses are a type of positive-sense single-stranded RNA virus with envelope and widely exist in nature to cause respiratory infectious diseases. The novel coronavirus is a new outbreak virus that is susceptible to all people. Up to now, the disease has been widely spread in the world and poses a great threat to public health. In this review, the genomic features, key proteins, host infection and replication of coronaviruses and novel coronaviruses are reviewed in order to provide theoretical basis for the study of the pathogenic mechanism of virus infection on host cells and to provide basic support for the development of specific antiviral drugs.
Betacoronavirus/physiology* ; COVID-19 ; Coronavirus Infections/virology* ; Humans ; Pandemics ; Pneumonia, Viral/virology* ; SARS-CoV-2 ; Virus Replication

OBJECTIVE: This study summarizes and compares clinical and laboratory characteristics of 34 patients admitted to the intensive care unit (ICU) for complications from coronavirus disease 2019 (COVID-19) at the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China from Jan. 22 to Mar. 5, 2020. METHODS: A total of 34 patients were divided into two groups, including those who required noninvasive ventilation (NIV) and invasive mechanical ventilation (IMV) with additional extracorporeal membrane oxygenation (ECMO) in 11 patients. Clinical features of COVID-19 patients were described and the parameters of clinical characteristics between the two groups were compared. RESULTS: The rates of the acute cardiac and kidney complications were higher in IMV cases than those in NIV cases. Most patients had lymphocytopenia on admission, with lymphocyte levels dropping progressively on the following days, and the more severe lymphopenia developed in the IMV group. In both groups, T lymphocyte counts were below typical lower limit norms compared to B lymphocytes. On admission, both groups had higher than expected amounts of plasma interleukin-6 (IL-6), which over time declined more in NIV patients. The prothrombin time was increased and the levels of platelet, hemoglobin, blood urea nitrogen (BUN), D-dimer, lactate dehydrogenase (LDH), and IL-6 were higher in IMV cases compared with NIV cases during hospitalization. CONCLUSIONS Data showed that the rates of complications, dynamics of lymphocytopenia, and changes in levels of platelet, hemoglobin, BUN, D-dimer, LDH and IL-6, and prothrombin time in these ICU patients were significantly different between IMV and NIV cases.
Acute Kidney Injury ; virology ; Aged ; Aged, 80 and over ; Betacoronavirus ; Blood Urea Nitrogen ; China ; Coronavirus Infections ; complications ; therapy ; Extracorporeal Membrane Oxygenation ; Female ; Fibrin Fibrinogen Degradation Products ; analysis ; Heart Diseases ; virology ; Hemoglobins ; analysis ; Hospitalization ; Humans ; Intensive Care Units ; Interleukin-6 ; blood ; L-Lactate Dehydrogenase ; blood ; Lymphopenia ; virology ; Male ; Middle Aged ; Noninvasive Ventilation ; Pandemics ; Pneumonia, Viral ; complications ; therapy ; Positive-Pressure Respiration ; Prothrombin Time ; Retrospective Studies

ORF3 protein, the single accessory protein encoded by porcine epidemic diarrhea virus (PEDV), is related to viral pathogenicity. In order to determine the cytoplasmic location signal of PEDV ORF3, we constructed a series of recombinant plasmids carrying full-length or truncated segments of PEDV DR13 ORF3 protein. When the acquired plasmids were transfected into Vero cells, expression and distribution of the EGFP-fused full-length ORF3 protein and its truncated forms in the cells were observed by laser confocal microscopy. The results showed that ORF3 protein or their truncated forms containing 40-91 aa segment including two transmembrane domains were localized in the cytoplasm, whereas ORF3 truncated peptides without the 40-91 aa segment were distributed in the whole cell (in both cytoplasm and nucleus). This suggests that the 40-91 aa is the key structural domain determining cytoplasmic location of PEDV ORF3 protein. The discovery provides reference for further clarifying intracellular transport and biological function of PEDV ORF3 protein.
Amino Acid Sequence ; Animals ; Chlorocebus aethiops ; Coronavirus Infections ; virology ; Cytoplasm ; virology ; Porcine epidemic diarrhea virus ; genetics ; Protein Domains ; Swine ; Vero Cells ; Viral Proteins ; chemistry ; metabolism

We optimized a fluorescent quantitative polymerase chain reaction (qPCR) assay system for rapid and real time detection of SARS-CoV-2 RNA. The results show that the lowest dilution of RNA samples used for the detection of SARS-CoV-2 RNA could reach 1/10 000 (the initial value is set as 10 ng/μL). Moreover, the cycle threshold (Ct) for samples of clinically diagnosed COVID-19 was lower than 35 or 40. The sensitivity of this method was satisfactory. The results were consistent with those of the COVID-19 detection kit on the market under the same conditions, but the number of cycles required was shortened by about 2. Therefore, the optimized assay developed in this study can be used in screening and early clinical diagnosis. Our work provides a tool to facilitate rapid clinical diagnosis of COVID-19.
Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnosis ; virology ; Early Diagnosis ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; Polymerase Chain Reaction ; methods ; standards ; RNA, Viral ; analysis ; genetics ; Sensitivity and Specificity ; Time Factors

BACKGROUND: With the rapid spread of novel coronavirus pneumonia (NCP) worldwide and the escalation of prevention and control efforts, the routine medical needs of patients have been restricted. The aims were to investigate medical needs of lung cancer patients and their mental health status during the epidemic periods, so as to provide rational recommendations for subsequent diagnosis and treatment. METHODS: The questionnaire was sent in the form of an electronic questionnaire at 7am on 4th, March, 2020, until 7am 6th, March, 2020, 368 questionnaires were recollected from 25 provinces (autonomous regions/municipalities) in 48 h. RESULTS: Of the 368 patients, 18 patients were excluded as they didn't receive anti-tumor treatment, and 350 patients were included in the final analysis. 229 cases were treated with oral targeted drugs, and 121 cases were treated with chemotherapy or immunotherapy. 41.3% of patients treated with intravenous chemotherapy or immunotherapy experienced treatment discontinuation, and the proportion of treatment discontinuation in chemotherapy or immunotherapy was higher than those treated with oral targeted drugs (21.0%). Whether oral targeted drugs or intravenous chemotherapy or immunotherapy, more than 60% of patients experienced delays in imaging examinations. Nearly one third of patients developed new symptoms or exacerbation of existing symptoms. 26.6%-28.9% of patients have changed their treatment plans through online consultation. During novel coronavirus pneumonia, 40%-75% of lung cancer patients have mental health problems, and more than 95% of patients support government's prevention and control measures. CONCLUSIONS During the emergence of NCP, the medical needs of patients with lung cancer have not been enough, especially those who discontinued chemotherapy or immunotherapy. When medical institution resumes work, priority should be given to them. At the same time, mental health problems of patients should be valued and resolved timely.
Adult ; Aged ; Antineoplastic Agents ; therapeutic use ; Betacoronavirus ; physiology ; China ; epidemiology ; Coronavirus Infections ; epidemiology ; virology ; Female ; Humans ; Lung Neoplasms ; drug therapy ; psychology ; Male ; Middle Aged ; Pandemics ; Pneumonia ; epidemiology ; virology ; Pneumonia, Viral ; epidemiology ; virology ; Retrospective Studies

Cyclophilin A (CypA) is a widely distributed and highly conserved protein in organisms. It has peptidyl-prolyl cis/trans isomerase activity and is a receptor for cyclosporin A (CsA). Coronaviruses are enveloped, single-stranded, positive-sense RNA viruses. Seven types of coronaviruses are currently known to infect humans, among which SARS-CoV, MERS-CoV, and SARS-CoV-2 are fatal for humans. It is well established that CypA is essential for the replication of various coronaviruses such as SARS-CoV, CoV-229E, CoV-NL63, and FCoV. Additionally, CsA and its derivatives (ALV, NIM811, etc.) have obvious inhibitory effects on a variety of coronaviruses. These results suggest that CypA is a potential antiviral target and the existing drug CsA might be used as an anti-coronavirus drug. At the end of 2019, SARS-CoV-2 raged in China, which seriously theatern human health and causes huge economic lases. In view of this, we describe the effects of CypA on the replication of coronaviruses and the antiviral activities of its inhibitors, which will provide the scientific basis and ideas for the development of antiviral drugs for SARS-CoV-2.
Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; growth & development ; Coronavirus ; drug effects ; growth & development ; Coronavirus Infections ; drug therapy ; epidemiology ; virology ; Cyclophilin A ; antagonists & inhibitors ; Cyclosporine ; chemistry ; pharmacology ; therapeutic use ; Humans ; Pandemics ; Pneumonia, Viral ; drug therapy ; epidemiology ; virology ; SARS Virus ; drug effects ; growth & development ; Virus Replication ; drug effects

An epidemic of acute respiratory syndrome in humans, which appeared in Wuhan, China in December 2019, was caused by a novel coronavirus (SARS-CoV-2). This disease was named as "Coronavirus Disease 2019" (COVID-19). SARS-CoV-2 was first identified as an etiological pathogen of COVID-19, belonging to the species of severe acute respiratory syndrome-related coronaviruses (SARSr-CoV). The speed of both the geographical transmission and the sudden increase in numbers of cases is much faster than SARS and Middle East respiratory syndrome (MERS). COVID-19 is the first global pandemic caused by a coronavirus, which outbreaks in 211 countries/territories/areas. The vaccine against COVID-19, regarded as an effective prophylactic strategy for control and prevention, is being developed in about 90 institutions worldwide. The experiences and lessons encountered in the previous SARS and MERS vaccine research can be used for reference in the development of COVID-19 vaccine. The present paper hopes to provide some insights for COVID-19 vaccines researchers.
Betacoronavirus ; immunology ; Biomedical Research ; Coronavirus Infections ; epidemiology ; immunology ; prevention & control ; virology ; Humans ; Internationality ; Middle East Respiratory Syndrome Coronavirus ; immunology ; Pandemics ; prevention & control ; Pneumonia, Viral ; epidemiology ; immunology ; prevention & control ; virology ; SARS Virus ; immunology ; Severe Acute Respiratory Syndrome ; immunology ; Viral Vaccines ; immunology

The ongoing outbreak of the coronavirus disease 2019 (COVID-19) as named by the World Health Organization has millions of confirmed cases around the world and has claimed hundreds of thousands of lives. The virus was named SARS-CoV-2 in February by International Committee on Taxonomy of Viruses. COVID-19 presents as fever, dry cough, dyspnea, headache and pneumonia. In a small subset of severe cases, the disease quickly progresses to respiratory failure and even death. Since the 21st century, there have been three major outbreaks caused by human coronaviruses, including the severe acute respiratory syndrome (SARS) that broke out in 2003, the Middle East respiratory syndrome (MERS) in 2012, and the recent pandemic of COVID-19. Since 2003, significant progress has been made in the study of SARS-CoV and MERS-CoV concerning their natural origins, pathogenesis, antiviral development and vaccine design. Since SARS-CoV-2 and SARS-CoV are closely related, previous findings on SARS-CoV are highly relevant to a better understanding as well as diagnosis, treatment, prevention and control of SARS-CoV-2. In this review, we highlight recent progresses in the field; compare the biological characteristics of SARS-CoV and SARS-CoV-2; summarize the urgently-needed diagnostic, treatment, prevention and control options; and provide future perspectives for the outcome of the outbreak and research questions to be answered, including some of the difficulties in vaccine development. Hopefully, our comments and suggestions would prove useful for the control of the SARS-CoV-2 epidemic in China and the world.
Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; immunology ; pathogenicity ; Coronavirus Infections ; diagnosis ; prevention & control ; therapy ; virology ; Humans ; Middle East Respiratory Syndrome Coronavirus ; drug effects ; immunology ; pathogenicity ; Pandemics ; prevention & control ; Pneumonia, Viral ; diagnosis ; prevention & control ; therapy ; virology ; SARS Virus ; drug effects ; immunology ; pathogenicity ; Severe Acute Respiratory Syndrome ; diagnosis ; prevention & control ; therapy ; virology ; Viral Vaccines