Human Coronavirus 229E Infection Inactivates Pyroptosis Executioner Gasdermin D but Ultimately Leads to Lytic Cell Death Partly Mediated by Gasdermin E.

Human coronavirus 229E (HCoV-229E) is associated with upper respiratory tract infections and generally causes mild respiratory symptoms. HCoV-229E infection can cause cell death, but the molecular pathways that lead to virus-induced cell death as well as the interplay between viral proteins and cellular cell death effectors remain poorly characterized for HCoV-229E. Studying how HCoV-229E and other common cold coronaviruses interact with and affect cell death pathways may help to understand its pathogenesis and compare it to that of highly pathogenic coronaviruses. Here, we report that the main protease (Mpro) of HCoV-229E can cleave gasdermin D (GSDMD) at two different sites (Q29 and Q193) within its active N-terminal domain to generate fragments that are now unable to cause pyroptosis, a form of lytic cell death normally executed by this protein. Despite GSDMD cleavage by HCoV-229E Mpro, we show that HCoV-229E infection still leads to lytic cell death. We demonstrate that during virus infection caspase-3 cleaves and activates gasdermin E (GSDME), another key executioner of pyroptosis. Accordingly, GSDME knockout cells show a significant decrease in lytic cell death upon virus infection. Finally, we show that HCoV-229E infection leads to increased lytic cell death levels in cells expressing a GSDMD mutant uncleavable by Mpro (GSDMD Q29A+Q193A). We conclude that GSDMD is inactivated by Mpro during HCoV-229E infection, preventing GSDMD-mediated cell death, and point to the caspase-3/GSDME axis as an important player in the execution of virus-induced cell death. In the context of similar reported findings for highly pathogenic coronaviruses, our results suggest that these mechanisms do not contribute to differences in pathogenicity among coronaviruses. Nonetheless, understanding the interactions of common cold-associated coronaviruses and their proteins with the programmed cell death machineries may lead to new clues for coronavirus control strategies.

Enterocin DD14 can inhibit the infection of eukaryotic cells with enveloped viruses.

Bacteriocins are ribosomally synthesized bacterial peptides endowed with antibacterial, antiprotozoal, anticancer and antiviral activities. In the present study, we evaluated the antiviral activities of two bacteriocins, enterocin DD14 (EntDD14) and lacticaseicin 30, against herpes simplex virus type 1 (HSV-1), human coronavirus 229E (HCoV-229E) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Vero, Huh7 and Vero E6 cells, respectively. In addition, the interactions of these bacteriocins with the envelope glycoprotein D of HSV-1 and the receptor binding domains of HCoV-229E and SARS-CoV-2 have been computationally evaluated using protein-protein docking and molecular dynamics simulations. HSV-1 replication in Vero cells was inhibited by EntDD14 and, to a lesser extent, by lacticaseicin 30 added to cells after virus inoculation. EntDD14 and lacticaseicin 30 had no apparent antiviral activity against HCoV-229E; however, EntDD14 was able to inhibit SARS-CoV-2 in Vero E6 cells. Further studies are needed to elucidate the antiviral mechanism of these bacteriocins.

Novel synthesis of the first new class of triazine sulfonamide thioglycosides and the evaluation of their anti-tumor and anti-viral activities against human coronavirus.

Novel class of triazine sulfonamide thioglycosides was designed and synthesized. Those novel structures comprising three essential and pharmacological significant moieties such as the triazine, sulfonamide, and thioglycosidic scaffolds. The triazine sulfonamides were furnished via a direct approach starting from potassium cyanocarbonimidodithioate, then the corresponding triazine sulfonamide thioglycosides were generated using the peracylated α-d-gluco- and galacto-pyranosyl bromides. Anti-viral evaluation of compounds in vitro against HCoV-229E virus revealed that some compounds possess promising activity. Compounds 4a, 4b, 4d, 6d and 6e indicate from moderate to low antiviral activity against low pathogenic coronavirus 229E in comparison with remdesivir at a concentration of 100 µg/mL. Additionally their in vitro anti-proliferative effects against NCI 60 cancer cell lines cell lines were also investigated. Compound 4a, the most potent compound among the estimated compounds, revealed remarkably lowest cell growth promotion against CNS cancer SNB-75, and renal cancer UO-31.

Deciphering the similarities and disparities of molecular mechanisms behind respiratory epithelium response to HCoV-229E and SARS-CoV-2 and drug repurposing, a systems biology approach.

PURPOSE: Identifying the molecular mechanisms behind SARS-CoV-2 disparities and similarities will help find new treatments. The present study determines networks' shared and non-shared (specific) crucial elements in response to HCoV-229E and SARS-CoV-2 viruses to recommend candidate medications. METHODS: We retrieved the omics data on respiratory cells infected with HCoV-229E and SARS-CoV-2, constructed PPIN and GRN, and detected clusters and motifs. Using a drug-gene interaction network, we determined the similarities and disparities of mechanisms behind their host response and drug-repurposed. RESULTS: CXCL1, KLHL21, SMAD3, HIF1A, and STAT1 were the shared DEGs between both viruses' protein-protein interaction network (PPIN) and gene regulatory network (GRN). The NPM1 was a specific critical node for HCoV-229E and was a Hub-Bottleneck shared between PPI and GRN in HCoV-229E. The HLA-F, ADCY5, TRIM14, RPF1, and FGA were the seed proteins in subnetworks of the SARS-CoV-2 PPI network, and HSPA1A and RPL26 proteins were the seed in subnetworks of the PPI network of HCOV-229E. TRIM14, STAT2, and HLA-F played the same role for SARS-CoV-2. Top enriched KEGG pathways included cell cycle and proteasome in HCoV-229E and RIG-I-like receptor, Chemokine, Cytokine-cytokine, NOD-like receptor, and TNF signaling pathways in SARS-CoV-2. We suggest some candidate medications for COVID-19 patient lungs, including Noscapine, Isoetharine mesylate, Cycloserine, Ethamsylate, Cetylpyridinium, Tretinoin, Ixazomib, Vorinostat, Venetoclax, Vorinostat, Ixazomib, Venetoclax, and epoetin alfa for further in-vitro and in-vivo investigations. CONCLUSION: We suggested CXCL1, KLHL21, SMAD3, HIF1A, and STAT1, ADCY5, TRIM14, RPF1, and FGA, STAT2, and HLA-F as critical genes and Cetylpyridinium, Cycloserine, Noscapine, Ethamsylate, Epoetin alfa, Isoetharine mesylate, Ribavirin, and Tretinoin drugs to study further their importance in treating COVID-19 lung complications.

Metabolic profiling of milk thistle different organs using UPLC-TQD-MS/MS coupled to multivariate analysis in relation to their selective antiviral potential.

INTRODUCTION: Silybum marianum commonly known as milk thistle is one of the most imperative medicinal plants due to its remarkable pharmacological activities. Lately, the antiviral activities of S. marianum extract have been studied and it showed effectiveness against many viruses. OBJECTIVE: Although most previous studies were concerned mainly with silymarin content of the fruit, the present study provides comprehensive comparative evaluation of S. marianum different organs' chemical profiles using UPLC-MS/MS coupled to chemometrics to unravel potentially selective antiviral compounds against human coronavirus (HCoV-229E). METHODOLOGY: UPLC-ESI-TQD-MS/MS analysis was utilized to establish metabolic fingerprints for S. marianum organs namely fruits, roots, stems and seeds. Multivariate analysis, using OPLS-DA and HCA-heat map was applied to explore the main discriminatory phytoconstituents between organs. Selective virucidal activity of organs extracts against coronavirus (HCoV-229E) was evaluated for the first time using cytopathic effect (CPE) inhibition assay. Correlation coefficient analysis was implemented for detection of potential constituents having virucidal activity. RESULTS: UPLC-MS/MS analysis resulted in 87 identified metabolites belonging to different classes. OPLS-DA revealed in-between class discrimination between milk thistle organs proving their significantly different metabolic profiles. The results of CPE assay showed that all tested organ samples exhibited dose dependent inhibitory activity in nanomolar range. Correlation analysis disclosed that caffeic acid-O-hexoside, gadoleic and linolenic acids were the most potentially selective antiviral phytoconstituents. CONCLUSION: This study valorizes the importance of different S. marianum organs as wealthy sources of selective and effective antiviral candidates. This approach can be extended to unravel potentially active constituents from complex plant matrices.

Antibacterial and anti-coronavirus investigation of selected Senegalese plant species according to an ethnobotanical survey.

ETHNOPHARMACOLOGICAL RELEVANCE: In Senegal, upper and lower respiratory tract infections constitute a real health problem. To manage these disorders, most people rely on the use of local medicinal plants. This is particularly the case for species belonging to the botanical families, Combretaceae, Fabaceae, Myrtaceae and Rubiaceae, which are widely used to treat various respiratory problems such as colds, flu, rhinitis, sinusitis, otitis, angina, bronchitis, bronchiolitis and also pneumonia. AIM OF THE STUDY: The aim of this study was to identify medicinal plants traditionally used for the management of infectious diseases, in particular those of the respiratory tract. On the basis of these ethnopharmacological uses, this study made it possible to highlight the antibacterial, antiviral and cytotoxic activities of selected plant species. MATERIALS AND METHODS: An ethnobotanical survey was conducted in Senegal among informants, including herbalists, traditional healers, and households, using medicinal plants in the management of infectious diseases, with a focus on respiratory tract infections. The most cited plant species were evaluated in vitro on a panel of 18 human pathogenic bacteria may be involved in respiratory infections and against the human coronavirus HCoV-229E in Huh-7 cells. The antiviral activity of the most active extracts against HCoV-229E was also evaluated on COVID-19 causing agent, SARS-CoV-2 in Vero-81 cells. In parallel, cytotoxic activities were evaluated on Huh-7 cells. RESULTS: A total of 127 informants, including 100 men (78.74%) and 27 women (21.26%) participated in this study. The ethnobotanical survey led to the inventory of 41 plant species belonging to 19 botanical families used by herbalists and/or traditional healers and some households to treat infectious diseases, with a specific focus on upper respiratory tract disorders. Among the 41 plant species, the most frequently mentioned in the survey were Guiera senegalensis J.F. Gmel. (95.2%), Combretum glutinosum Perr. Ex DC. (93.9%) and Eucalyptus spp. (82.8%). Combretaceae (30.2%) represented the most cited botanical family with six species, followed by Fabaceae (29.3%, 12 species). A total of 33 crude methanolic extracts of the 24 plant species selected for their number of citations were evaluated in vitro for their antimicrobial and cytotoxic activities. Guiera senegalensis, Combretum glutinosum, Vachellia nilotica subsp. tomentosa (Benth.) Kyal. & Boatwr, Eucalyptus camaldulensis Dehnh., and Terminalia avicennioides Guill. & Perr., showed antibacterial activities. The most active plants against HCoV-229E were: Ficus sycomorus L., Mitragyna inermis (Willd.) Kuntze, Pterocarpus erinaceus Poir., and Spermacoce verticillata L. One of these plants, Mitragyna inermis, was also active against SARS-CoV-2. CONCLUSION: This work confirmed the anti-infective properties of plant species traditionally used in Senegal. Overall, the most frequently cited plant species showed the best antibacterial activities. Moreover, some of the selected plant species could be considered as a potential source for the management of coronavirus infections. This new scientific data justified the use of these plants in the management of some infectious pathologies, especially those of the respiratory tract.

Utilizing network pharmacology and experimental validation to investigate the underlying mechanism of Denglao Qingguan decoction against HCoV-229E.

Background: Denglao Qingguan decoction (DLQGD) has been extensively utilized for the treatment of colds, demonstrating significant therapeutic efficacy. Human Coronavirus 229E (HCoV-229E) is considered a crucial etiological agent of influenza. However, the specific impact and underlying mechanisms of DLQGD on HCoV-229E remain poorly understood. Methods: Active ingredients and targets information of DLQGD were collected from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), literature search, and Swiss ADEM database. The Genecard database was used to collect HCoV-229E related targets. We built an "ingredient-target network" through Cytoscape. Protein - Protein interaction (PPI) networks were mapped using the String database. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) were enriched using the DAVID database. Then, we used molecular docking techniques to verify the binding activity between the core compounds and the core gene targets. Finally, in vitro experiments were conducted to validate DLQGD's antiviral activity against HCoV-229E and assess its anti-inflammatory effects. Results: In total, we identified 227 active components in DLQGD. 18 key targets involved in its activity against HCoV-229E. Notably, the core active ingredients including quercetin, luteolin, kaempferol, ß-sitosterol, and apigenin, and the core therapeutic targets were CXCL8, RELA, MAPK14, NFKB1, and CXCL10, all associated with HCoV-229E. KEGG enrichment results included IL-17 signaling pathway, Toll-like receptor signaling pathway, RIG-I-like receptor signaling pathway and so on. The core active ingredients and the core therapeutic targets and Human Aminopeptidase N (ANPEP) all showed good binding activity by molecular docking verification. In vitro, DLQGD exhibited anti-HCoV-229E activity and anti-inflammatory effects. Conclusion: Our study suggests that DLQGD has both effects of anti-HCoV-229E and anti-inflammatory. The core active ingredients (quercetin, luteolin, kaempferol, ß-sitosterol, apigenin) and the core therapeutic targets (CXCL8, RELA, MAPK14, NFKB1, CXCL10) may play key roles in the pharmacological action of DLQGD against HCoV-229E.

Repurposing screen identifies novel candidates for broad-spectrum coronavirus antivirals and druggable host targets.

Libraries composed of licensed drugs represent a vast repertoire of molecules modulating physiological processes in humans, providing unique opportunities for the discovery of host-targeting antivirals. We screened the Repurposing, Focused Rescue, and Accelerated Medchem (ReFRAME) repurposing library with approximately 12,000 molecules for broad-spectrum coronavirus antivirals and discovered 134 compounds inhibiting an alphacoronavirus and mapping to 58 molecular target categories. Dominant targets included the 5-hydroxytryptamine receptor, the dopamine receptor, and cyclin-dependent kinases. Gene knock-out of the drugs' host targets including cathepsin B and L (CTSB/L; VBY-825), the aryl hydrocarbon receptor (AHR; Phortress), the farnesyl-diphosphate farnesyltransferase 1 (FDFT1; P-3622), and the kelch-like ECH-associated protein 1 (KEAP1; Omaveloxolone), significantly modulated HCoV-229E infection, providing evidence that these compounds inhibited the virus through acting on their respective host targets. Counter-screening of all 134 primary compound candidates with SARS-CoV-2 and validation in primary cells identified Phortress, an AHR activating ligand, P-3622-targeting FDFT1, and Omaveloxolone, which activates the NFE2-like bZIP transcription factor 2 (NFE2L2) by liberating it from its endogenous inhibitor KEAP1, as antiviral candidates for both an Alpha- and a Betacoronavirus. This study provides an overview of HCoV-229E repurposing candidates and reveals novel potentially druggable viral host dependency factors hijacked by diverse coronaviruses.

Endemic Human Coronavirus-Specific Nasal Immunoglobulin A and Serum Immunoglobulin G Dynamics in Lower Respiratory Tract Infections.

Endemic human coronaviruses (HCoV) NL63, 229E, OC43, and HKU1 cause respiratory infection. Following infection, a virus-specific serum antibody rise is usually observed, coinciding with recovery. In some cases, an infection is not accompanied by an immunoglobulin G (IgG) antibody rise in serum in the first month after HCoV infection, even though the infection has cleared in that month and the patient has recovered. We investigated the possible role of nasal immunoglobulin A (IgA). We measured spike (S) and nucleocapsid (N)-specific nasal IgA during and after an HCoV lower respiratory tract infection (LRTI) and compared the IgA responses between subjects with and without a significant IgG rise in serum (IgG responders (n = 31) and IgG non-responders (n = 14)). We found that most IgG responders also exhibited significant nasal IgA rise in the first month after the infection, whereas such an IgA rise was lacking in most IgG non-responders. Interestingly, the serum IgG non-responders presented with a significantly higher nasal IgA when they entered this study than during the acute phase of the LRTI. Our data suggest that nasal IgA could be part of a fast acute response to endemic HCoV infection and may play a role in clearing the infection.

Role and mechanism of protein kinase D in the replication of human coronavirus 229E / 中国人兽共患病学报

This study investigated the role of protein kinase D(PKD)in the replication of human coronavirus 229E(HCoV-229E)and its potential molecular mechanisms.Using MRC-5 cells as a model,we assessed the expression levels of PKD family genes and proteins through qPCR and western blotting.We knocked down Prkd3 with siRNA and inhibited PKD activity with CRT0066101 to examine the replication lev-els of HCoV-229E-infected cells.Cell viability was assessed with CCK8,viral titration was determined with the TCID50,and immunofluorescence staining was used to assess HCoV-229E expression and the structure of the trans-Golgi network(TGN).The level of phosphatidylinositol 4,5-bisphosphate(PI(4,5)P2)was measured to reflect phosphatidylinositol 4-kinaseⅢβ(PI4KⅢβ)activity.PI4KⅢβ activity was inhibited with a PI4KⅢβ inhibitor(BQR695)to observe changes in TGN struc-ture and HCoV-229E replication after cell infection.CRT0066101 was used to inhibit PKD activity in Vero-E6 cells,and HCoV-229E replication levels were examined post-infection.The expression levels of PKD family genes and proteins,including Prkd1,Prkd2 and Prkd3,significantly increased during HCoV-229E infection.Knockdown of PKD3 significantly inhibited HCoV-229E mRNA levels and titers with respect to those in the control group(t=8.999,P＜0.001;t=6.920,P＜0.001),whereas overexpression of PKD3 increased HCoV-229E mRNA levels and titers(t=6.630,P＜0.001;t=5.794,P＜0.001).CRT0066101 also significantly inhibited HCoV-229E mRNA levels and titers(t=6.931,P＜0.001;t=4.055,P＜0.01).Im-munofluorescence staining indicated that CRT0066101 inhibited TGN fission caused by HCoV-229E infection.Inhibition of PI4KⅢβ activity significantly decreased PI(4,5)P2 levels,and BQR695 rescued the elevated PI(4,5)P2 levels caused by PKD overexpression(t=6.671,P＜0.01).BQR695 decreased TGN fission in HCoV-229E-infected cells,and HCoV-229E mRNA levels and titers(t=5.151,P＜0.001;t=7.744,P＜0.001).CRT0066101 inhibited HCoV-229E mRNA levels and titers in Vero-E6 cells(t=7.480,P＜0.001;t=7.228,P＜0.01).This study revealed that PKD regulates TGN fission through modu-latingPI4KⅢβ and is involved in HCoV-229E replication.PKD inhibitors and PI4KⅢβ inhibitors significantly decreased HCoV-229E replication,thus providing important insights for future research onthe treatment of coronavirus infections.

Therapeutic Effect of Gegentang Granules on Mouse Model with hCoV-229E Pneumonia and Hanshi Yidu Xifei Syndrome / 中国实验方剂学杂志

ObjectiveTo determine the therapeutic effect of Gegentang granules on a disease-syndrome mouse model combining human coronavirus 229E （hCoV-229E） pneumonia with Hanshi Yidu Xifei syndrome in vivo. MethodMice were randomly divided into normal group， infection group， cold-dampness group， model group， chloroquine phosphate group （0.18 g·kg-1）， interferon-α2b （IFN-α2b） group （1.83×106 U·kg-1）， Gegentang granules high-dose and low-dose groups （6.6， 3.3 g·kg-1） with 10 mice in each group. Cold-dampness environment and hCoV-229E infection were used for modeling， and the general status and lung index of mice in each group were observed. The viral load in lung tissue was detected by real-time fluorescent quantitative polymerase chain reaction （Real-time PCR）， the pathological changes in lung tissue were evaluated by hematoxylin-eosin （HE） staining， the levels of serum gastrointestinal hormones and inflammatory factors in lung tissue were detected by enzyme-linked immunosorbent assay （ELISA）， and the percentage of peripheral blood lymphocytes was detected by flow cytometry. ResultComparing with model group， Gegentang granules could significantly alleviate the physical signs of Hanshi Yidu Xifei syndrome， including listlessness， weakness of limbs， sticky stool， etc. Comparing with model group， Gegentang granules high-dose group significantly reduced lung index， histopathological score of interstitial lung and bronchus， and the level of serum motilin （P<0.05， P<0.01）， two doses of Gegentang granules could significantly increase the level of serum gastrin （P<0.05， P<0.01）， the percentage of CD4+， CD8+ T lymphocytes in peripheral blood （P<0.05， P<0.01）， and the level of tumor necrosis factor-α （TNF-α） in lung tissue was significantly decreased （P<0.01）， and the level of interleukin-6 （IL-6） showed decreasing tendency. ConclusionGegentang granules has therapeutic effect on model mice. It can improve the appearance and behavior characterization， regulate the level of gastrointestinal hormones， decrease lung index and histopathological score， and possibly play an immunomodulatory role by inhibiting the expression of inflammatory cytokines in lung tissue and restoring the percentage of peripheral blood lymphocytes.

Therapeutic Effect of Gegentang Granules on Mouse Model with hCoV-229E Pneumonia and Hanshi Yidu Xifei Syndrome / 中国实验方剂学杂志

ObjectiveTo determine the therapeutic effect of Gegentang granules on a disease-syndrome mouse model combining human coronavirus 229E （hCoV-229E） pneumonia with Hanshi Yidu Xifei syndrome in vivo. MethodMice were randomly divided into normal group， infection group， cold-dampness group， model group， chloroquine phosphate group （0.18 g·kg-1）， interferon-α2b （IFN-α2b） group （1.83×106 U·kg-1）， Gegentang granules high-dose and low-dose groups （6.6， 3.3 g·kg-1） with 10 mice in each group. Cold-dampness environment and hCoV-229E infection were used for modeling， and the general status and lung index of mice in each group were observed. The viral load in lung tissue was detected by real-time fluorescent quantitative polymerase chain reaction （Real-time PCR）， the pathological changes in lung tissue were evaluated by hematoxylin-eosin （HE） staining， the levels of serum gastrointestinal hormones and inflammatory factors in lung tissue were detected by enzyme-linked immunosorbent assay （ELISA）， and the percentage of peripheral blood lymphocytes was detected by flow cytometry. ResultComparing with model group， Gegentang granules could significantly alleviate the physical signs of Hanshi Yidu Xifei syndrome， including listlessness， weakness of limbs， sticky stool， etc. Comparing with model group， Gegentang granules high-dose group significantly reduced lung index， histopathological score of interstitial lung and bronchus， and the level of serum motilin （P<0.05， P<0.01）， two doses of Gegentang granules could significantly increase the level of serum gastrin （P<0.05， P<0.01）， the percentage of CD4+， CD8+ T lymphocytes in peripheral blood （P<0.05， P<0.01）， and the level of tumor necrosis factor-α （TNF-α） in lung tissue was significantly decreased （P<0.01）， and the level of interleukin-6 （IL-6） showed decreasing tendency. ConclusionGegentang granules has therapeutic effect on model mice. It can improve the appearance and behavior characterization， regulate the level of gastrointestinal hormones， decrease lung index and histopathological score， and possibly play an immunomodulatory role by inhibiting the expression of inflammatory cytokines in lung tissue and restoring the percentage of peripheral blood lymphocytes.

Repurposing carrimycin as an antiviral agent against human coronaviruses, including the currently pandemic SARS-CoV-2

COVID-19 pandemic caused by SARS-CoV-2 infection severely threatens global health and economic development. No effective antiviral drug is currently available to treat COVID-19 and any other human coronavirus infections. We report herein that a macrolide antibiotic, carrimycin, potently inhibited the cytopathic effects (CPE) and reduced the levels of viral protein and RNA in multiple cell types infected by human coronavirus 229E, OC43, and SARS-CoV-2. Time-of-addition and pseudotype virus infection studies indicated that carrimycin inhibited one or multiple post-entry replication events of human coronavirus infection. In support of this notion, metabolic labelling studies showed that carrimycin significantly inhibited the synthesis of viral RNA. Our studies thus strongly suggest that carrimycin is an antiviral agent against a broad-spectrum of human coronaviruses and its therapeutic efficacy to COVID-19 is currently under clinical investigation.

Detection of four human coronaviruses in respiratory infections in children in Fuzhou, China / 中华实验和临床病毒学杂志

Objective@#In this study, we tested for the presence of four human coronaviruses (HCoVs) in children with respiratory tract disease in Fuzhou, Fujian, China.@*Methods@#Nasopharyngeal aspirates were collected from children with respiratory tract disease from Nov, 2007 to Jan, 2015. A total of 266 clinical samples were tested for HCoVs using reverse-transcription polymerase chain reaction (RT-PCR). The positive products were sequenced and compared with those in GenBank by BLAST. The positive samples were then tested for HCoV-HKU1 and HCoV-NL63 using RT-PCR method . We compared the 440 bp pol gene sequence of the 8 HCoV isolates in Fuzhou, China to other HCoV isolates documented in the GenBank database by using MEGA software version 6.06 and the neighbor-joining method .@*Results@#HCoVs were detected in 8 patients (3.0%) out of the 266 children. Two of 266 (0.38%) were positive for HCoV-HKU1; 1 of 266(0.38%)were positive for HCoV-NL63; 1 of 266 (0.38%) were positive for HCoV-229E; 4 of 266 (1.5%)were positive for HCoV-OC43. All of children who were positive for HCoV had respiratory illness. Two HCoV-HKU1 were found to co-infect with human parainfluenza virus type 3 (HPIV-3). The 8 HCoV strains in our study fell into four clusters. Two strains of HCoV-HKU1 were genotype A.@*Conclusions@#HCoV infections were probably associated with upper and lower respiratory illness in children. Additional studies are needed to investigate the potential roles of these HCoVs in diseases.

Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43

Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43.