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1.
Eur J Med Chem ; 244: 114857, 2022 Dec 15.
Article in English | MEDLINE | ID: covidwho-2130694

ABSTRACT

Although vaccines are greatly mitigating the worldwide pandemic diffusion of SARS-Cov-2, therapeutics should provide many distinct advantages as complementary approach to control the viral spreading. Here, we report the development of new tripeptide derivatives of AT1001 against SARS-CoV-2 Mpro. By molecular modeling, a small compound library was rationally designed and filtered for enzymatic inhibition through FRET assay, leading to the identification of compound 4. X-ray crystallography studies provide insights into its binding mode and confirm the formation of a covalent bond with Mpro C145. In vitro antiviral tests indicate the improvement of biological activity of 4 respect to AT1001. In silico and X-ray crystallography analysis led to 58, showing a promising activity against three SARS-CoV-2 variants and a valuable safety in Vero cells and human embryonic lung fibroblasts. The drug tolerance was also confirmed by in vivo studies, along with pharmacokinetics evaluation. In summary, 58 could pave the way to develop a clinical candidate for intranasal administration.


Subject(s)
COVID-19 , SARS-CoV-2 , Chlorocebus aethiops , Animals , Humans , Coronavirus 3C Proteases , Vero Cells , COVID-19/drug therapy , Viral Nonstructural Proteins , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Protease Inhibitors/chemistry , Molecular Docking Simulation
2.
Front Immunol ; 13: 1008084, 2022.
Article in English | MEDLINE | ID: covidwho-2119705

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global pandemic, resulting in great fatalities around the world. Although the antiviral roles of RNA interference (RNAi) have been well studied in plants, nematodes and insects, the antiviral roles of RNAi in mammalians are still debating as RNAi effect is suspected to be suppressed by interferon (IFN) signaling pathways in most cell types. To determine the role of RNAi in mammalian resistance to SARS-CoV-2, we studied the profiling of host small RNAs and SARS-CoV-2 virus-derived small RNAs (vsRNAs) in the early infection stages of Vero cells, an IFN-deficient cell line. We found that host microRNAs (miRNAs) were dysregulated upon SARS-CoV-2 infection, resulting in downregulation of microRNAs playing antiviral functions and upregulation of microRNAs facilitating viral proliferations. Moreover, vsRNA peaked at 22 nt at negative strand but not the positive strand of SARS-CoV-2 and formed successive Dicer-spliced pattern at both strands. Similar characteristics of vsRNAs were observed in IFN-deficient cell lines infected with Sindbis and Zika viruses. Together, these findings indicate that host cell may deploy RNAi pathway to combat SARS-CoV-2 infection in IFN-deficient cells, informing the alternative antiviral strategies to be developed for patients or tissues with IFN deficiency.


Subject(s)
COVID-19 , MicroRNAs , Zika Virus Infection , Zika Virus , Chlorocebus aethiops , Animals , Humans , Vero Cells , SARS-CoV-2/genetics , RNA, Viral/genetics , COVID-19/genetics , MicroRNAs/genetics , Antiviral Agents , Mammals
3.
Viruses ; 14(11)2022 Oct 31.
Article in English | MEDLINE | ID: covidwho-2118120

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) infection causes huge economic losses to the pig industry worldwide. DNAJA3, a member of the Hsp40 family proteins, is known to play an important role in the replication of several viruses. However, it remains unknown if it interacts with PEDV. We found that DNAJA3 interacted with PEDV S1, initially with yeast two-hybrid screening and later with Co-IP, GST pull-down, and confocal imaging. Further experiments showed the functional relationship between DNAJA3 and PEDV in the infected IPEC-J2 cells. DNAJA3 overexpression significantly inhibited PEDV replication while its knockdown had the opposite effect, suggesting that it is a negative regulator of PEDV replication. In addition, DNAJA3 expression could be downregulated by PEDV infection possibly as the viral strategy to evade the suppressive role of DNAJA3. By gene silencing and overexpression, we were able to show that DNAJA3 inhibited PEDV adsorption to IPEC-J2 cells but did not affect virus invasion. In conclusion, our study provides clear evidence that DNAJA3 mediates PEDV adsorption to host cells and plays an antiviral role in IPEC-J2 cells.


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine , Animals , Chlorocebus aethiops , Porcine epidemic diarrhea virus/genetics , Adsorption , Virus Replication , Vero Cells , Proteins/pharmacology
4.
Biol Pharm Bull ; 45(10): 1559-1563, 2022.
Article in English | MEDLINE | ID: covidwho-2114472

ABSTRACT

Dihydroceramide Δ4-desaturase 1 (DEGS1) enzymatic activity is inhibited with N-(4-hydroxyphenyl)-retinamide (4-HPR). We reported previously that 4-HPR suppresses severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry through a DEGS1-independent mechanism. However, it remains unclear whether DEGS1 is involved in other SARS-CoV-2 infection processes, such as virus replication and release. Here we established DEGS1 knockout (KO) in VeroE6TMPRSS2 cells. No significant difference was observed in virus production in the culture supernatant between wild-type (WT) cells and DEGS1-KO cells, although the levels of dihydroceramide (DHCer), a DEGS1 substrate, were significantly higher in DEGS1-KO cells than WT cells. Furthermore, the virus-induced cytopathic effect was also observed in DEGS1-KO cells. Importantly, the EC50 value of 4-HPR in DEGS1-KO cells was almost identical to the value reported previously in WT cells. Our results indicated the lack of involvement of DEGS1 in SARS-CoV-2 infection.


Subject(s)
COVID-19 , Fenretinide , Animals , Ceramides , Chlorocebus aethiops , Fatty Acid Desaturases , Fenretinide/pharmacology , Humans , Oxidoreductases , SARS-CoV-2 , Vero Cells
5.
Antiviral Res ; 208: 105429, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2104350

ABSTRACT

Vero cells are widely used for antiviral tests and virology research for SARS-CoV-2 as well as viruses from various other families. However, Vero cells generally express high levels of multi-drug resistance 1 (MDR1) or Pgp protein, the efflux transporter of foreign substances including many antiviral compounds, affecting the antiviral activity as well as interpretation of data. To address this, a Pgp gene knockout VeroE6 cell line (VeroE6-Pgp-KO) was generated using CRISPR-CAS9 technology. These cells no longer expressed the Pgp protein as indicated by flow cytometry analysis following staining with a Pgp-specific monoclonal antibody. They also showed significantly reduced efflux transporter activity in the calcein acetoxymethyl ester (calcein AM) assay. The VeroE6-Pgp-KO cells and the parental VeroE6 cells were each infected with SARS-CoV-2 to test antiviral activities of remdesivir and nirmatrelvir, two known Pgp substrates, in the presence or absence of a Pgp inhibitor. The compounds showed antiviral activities in VeroE6-Pgp-KO cells similar to that observed in the presence of the Pgp inhibitor. Thus, the newly established VeroE6-Pgp-KO cell line adds a new in vitro virus infection system for SARS-CoV-2 and possibly other viruses to test antiviral therapies without a need to control the Pgp activity. Removal of the Pgp inhibitor for antiviral assays will lead to less data variation and prevent failed assays.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Chlorocebus aethiops , Animals , SARS-CoV-2/genetics , Antiviral Agents/pharmacology , Gene Knockout Techniques , Vero Cells , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , COVID-19/drug therapy , Cell Line
6.
J Virol ; 96(22): e0155522, 2022 Nov 23.
Article in English | MEDLINE | ID: covidwho-2097923

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) is a re-emerging enteric coronavirus currently spreading in several nations and inflicting substantial financial damages on the swine industry. The currently available coronavirus vaccines do not provide adequate protection against the newly emerging viral strains. It is essential to study the relationship between host antiviral factors and the virus and to investigate the mechanisms underlying host immune response against PEDV infection. This study shows that heterogeneous nuclear ribonucleoprotein K (hnRNP K), the host protein determined by the transcription factor KLF15, inhibits the replication of PEDV by degrading the nucleocapsid (N) protein of PEDV in accordance with selective autophagy. hnRNP K was found to be capable of recruiting the E3 ubiquitin ligase, MARCH8, aiming to ubiquitinate N protein. Then, it was found that the ubiquitinated N protein could be delivered into autolysosomes for degradation by the cargo receptor NDP52, thereby inhibiting PEDV proliferation. Moreover, based on the enhanced MyD88 expression, we found that hnRNP K activated the interferon 1 (IFN-1) signaling pathway. Overall, the data obtained revealed a new mechanism of hnRNP K-mediated virus restriction wherein hnRNP K suppressed PEDV replication by degradation of viral N protein using the autophagic degradation pathway and by induction of IFN-1 production based on upregulation of MyD88 expression. IMPORTANCE The spread of the highly virulent PEDV in many countries is still leading to several epidemic and endemic outbreaks. To elucidate effective antiviral mechanisms, it is important to study the relationship between host antiviral factors and the virus and to investigate the mechanisms underlying host immune response against PEDV infection. In the work, we detected hnRNP K as a new host restriction factor which can hinder PEDV replication through degrading the nucleocapsid protein based on E3 ubiquitin ligase MARCH8 and the cargo receptor NDP52. In addition, via the upregulation of MyD88 expression, hnRNP K could also activate the interferon (IFN) signaling pathway. This study describes a previously unknown antiviral function of hnRNP K and offers a new vision toward host antiviral factors that regulate innate immune response as well as a protein degradation pathway against PEDV infection.


Subject(s)
Coronavirus Infections , Heterogeneous-Nuclear Ribonucleoprotein K , Interferon Type I , Porcine epidemic diarrhea virus , Virus Replication , Animals , Antiviral Agents , Chlorocebus aethiops , Coronavirus Infections/veterinary , Heterogeneous-Nuclear Ribonucleoprotein K/genetics , Interferons , Myeloid Differentiation Factor 88 , Nucleocapsid Proteins/physiology , Porcine epidemic diarrhea virus/physiology , Swine , Swine Diseases/virology , Ubiquitin-Protein Ligases , Vero Cells , Interferon Type I/immunology
7.
Int J Mol Sci ; 23(20)2022 Oct 19.
Article in English | MEDLINE | ID: covidwho-2082045

ABSTRACT

There has been an immense effort by global pharmaceutical companies to develop anti-COVID-19 drugs, including small molecule-based RNA replication inhibitors via drug repositioning and antibody-based spike protein blockers related to cell entry by SARS-CoV-2. However, several limitations to their clinical use have emerged in addition to a lack of progress in the development of small molecule-based cell entry inhibitors from natural products. In this study, we tested the effectiveness of kuwanon C (KC), which has mainly been researched using in silico docking simulation and can serve as an effective building block for developing anti-COVID-19 drugs, in blocking the spike S1 RBD:ACE2 receptor interaction. KC is a natural product derived from Morus alba L., commonly known as mulberry, which has known antiviral efficacy. Molecular interaction studies using competitive ELISA and the BLItz system revealed that KC targets both the spike S1 RBD and the ACE2 receptor, successfully disrupting their interaction, as supported by the in silico docking simulation. Furthermore, we established a mechanism of action by observing how KC prevents the infection of SARS-CoV-2 spike pseudotyped virus in ACE2/TPRSS2-overexpressing HEK293T cells. Finally, we demonstrated that KC inhibits clinical isolates of SARS-CoV-2 in Vero cells. Future combinations of small molecule-based cell entry inhibitors, such as KC, with the currently prescribed RNA replication inhibitors are anticipated to significantly enhance the efficacy of COVID-19 therapies.


Subject(s)
Biological Products , COVID-19 , Morus , Chlorocebus aethiops , Animals , Humans , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , COVID-19/drug therapy , Spike Glycoprotein, Coronavirus/metabolism , Morus/metabolism , Vero Cells , HEK293 Cells , Peptidyl-Dipeptidase A/metabolism , Protein Binding , Antiviral Agents/pharmacology , Pharmaceutical Preparations , RNA/metabolism
8.
Viruses ; 14(10)2022 10 16.
Article in English | MEDLINE | ID: covidwho-2071840

ABSTRACT

Host-virus protein interactions are critical for intracellular viral propagation. Understanding the interactions between cellular and viral proteins may help us develop new antiviral strategies. Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe damage to the global swine industry. Here, we employed co-immunoprecipitation and liquid chromatography-mass spectrometry to characterize 426 unique PEDV nucleocapsid (N) protein-binding proteins in infected Vero cells. A protein-protein interaction network (PPI) was created, and gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analyses revealed that the PEDV N-bound proteins belong to different cellular pathways, such as nucleic acid binding, ribonucleoprotein complex binding, RNA methyltransferase, and polymerase activities. Interactions of the PEDV N protein with 11 putative proteins: tripartite motif containing 21, DEAD-box RNA helicase 24, G3BP stress granule assembly factor 1, heat shock protein family A member 8, heat shock protein 90 alpha family class B member 1, YTH domain containing 1, nucleolin, Y-box binding protein 1, vimentin, heterogeneous nuclear ribonucleoprotein A2/B1, and karyopherin subunit alpha 1, were further confirmed by in vitro co-immunoprecipitation assay. In summary, studying an interaction network can facilitate the identification of antiviral therapeutic strategies and novel targets for PEDV infection.


Subject(s)
Coronavirus Infections , Nucleic Acids , Porcine epidemic diarrhea virus , Swine Diseases , Chlorocebus aethiops , Swine , Animals , Porcine epidemic diarrhea virus/genetics , Vimentin/metabolism , Vero Cells , Nucleocapsid/metabolism , Nucleocapsid Proteins/genetics , Viral Proteins/metabolism , Coronavirus Infections/metabolism , Antiviral Agents/metabolism , RNA/metabolism , Heat-Shock Proteins/metabolism , Methyltransferases/metabolism , Heterogeneous-Nuclear Ribonucleoproteins/metabolism , DEAD-box RNA Helicases/metabolism , Ribonucleoproteins/metabolism , Karyopherins/metabolism , Nucleic Acids/metabolism
9.
Viruses ; 14(10)2022 10 15.
Article in English | MEDLINE | ID: covidwho-2071839

ABSTRACT

Porcine epidemic diarrhea virus (PEDV), a member of the family Coronaviridae, causes acute diarrhea, vomiting, dehydration, and high mortality in newborn piglets, and has caused significant economic losses in the pig industry. There are currently no specific drugs available to treat PEDV. Viruses depend exclusively on the cellular machinery to ensure an efficient replication cycle. In the present study, we found that small-molecule RAF265, an anticancer drug that has been shown to be a potent inhibitor of RAF, reduced viral loads of PEDV by 4 orders of magnitude in Vero cells, and protected piglets from virus challenge. RAF265 reduced PEDV production by mediating cytoskeleton arrangement and targeting the host cell's translation machinery. Treatment with RAF265 inhibited viral entry of PEDV S-glycoprotein pseudotyped viral vector particle (PEDV-pp), at half maximal effective concentrations (EC50) of 79.1 nM. RAF265 also presented potent inhibitory activity against viral infection by SARS-CoV-2-pp and SARS-CoV-pp. The present work may provide a starting point for further progress toward the development of antiviral strategies effective against coronavirus PEDV.


Subject(s)
COVID-19 , Porcine epidemic diarrhea virus , Swine Diseases , Chlorocebus aethiops , Animals , Swine , Vero Cells , SARS-CoV-2 , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use
10.
Viruses ; 14(10)2022 09 27.
Article in English | MEDLINE | ID: covidwho-2066543

ABSTRACT

Curcumin, the bioactive compound of the spice Curcuma longa, has already been reported as a potential COVID-19 adjuvant treatment due to its immunomodulatory and anti-inflammatory properties. In this study, SARS-CoV-2 was challenged with curcumin; moreover, curcumin was also coupled with laser light at 445 nm in a photodynamic therapy approach. Curcumin at a concentration of 10 µM, delivered to the virus prior to inoculation on cell culture, inhibited SARS-CoV-2 replication (reduction >99%) in Vero E6 cells, possibly due to disruption of the virion structure, as observed using the RNase protection assay. However, curcumin was not effective as a prophylactic treatment on already-infected Vero E6 cells. Notably, when curcumin was employed as a photosensitizer and blue laser light at 445 nm was delivered to a mix of curcumin/virus prior to the inoculation on the cells, virus inactivation was observed (>99%) using doses of curcumin that were not antiviral by themselves. Photodynamic therapy employing crude curcumin can be suggested as an antiviral option against SARS-CoV-2 infection.


Subject(s)
COVID-19 , Curcumin , Chlorocebus aethiops , Animals , Humans , SARS-CoV-2 , Photosensitizing Agents/pharmacology , Photosensitizing Agents/chemistry , Curcumin/pharmacology , COVID-19/drug therapy , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Vero Cells , Anti-Inflammatory Agents/pharmacology , Ribonucleases/pharmacology , Virus Replication
11.
Front Endocrinol (Lausanne) ; 13: 982246, 2022.
Article in English | MEDLINE | ID: covidwho-2065496

ABSTRACT

Results of previous studies provided evidence for the existence of a functional gonadotropin-inhibitory hormone (GnIH) system in the European sea bass, Dicentrarchus labrax, which exerted an inhibitory action on the brain-pituitary-gonadal axis of this species. Herein, we further elucidated the intracellular signaling pathways mediating in sea bass GnIH actions and the potential interactions with sea bass kisspeptin (Kiss) signaling. Although GnIH1 and GnIH2 had no effect on basal CRE-luc activity, they significantly decreased forskolin-elicited CRE-luc activity in COS-7 cells transfected with their cognate receptor GnIHR. Moreover, an evident increase in SRE-luc activity was noticed when COS-7 cells expressing GnIHR were challenged with both GnIH peptides, and this stimulatory action was significantly reduced by two inhibitors of the PKC pathway. Notably, GnIH2 antagonized Kiss2-evoked CRE-luc activity in COS-7 cells expressing GnIHR and Kiss2 receptor (Kiss2R). However, GnIH peptides did not alter NFAT-RE-luc activity and ERK phosphorylation levels. These data indicate that sea bass GnIHR signals can be transduced through the PKA and PKC pathways, and GnIH can interfere with kisspeptin actions by reducing its signaling. Our results provide additional evidence for the understanding of signaling pathways activated by GnIH peptides in teleosts, and represent a starting point for the study of interactions with multiple neuroendocrine factors on cell signaling.


Subject(s)
Bass , Animals , Bass/physiology , COS Cells , Chlorocebus aethiops , Chorionic Gonadotropin , Kisspeptins/metabolism , Signal Transduction
12.
Sci Rep ; 12(1): 17101, 2022 Oct 12.
Article in English | MEDLINE | ID: covidwho-2062276

ABSTRACT

Chlorella spp., Spirulina spp., and fucoidan dry powders, are commercialized as food supplements and are considered safe for human consumption. Their broad-spectrum antiviral properties have been studied, however, their effect against SARS-CoV-2 remains unknown. We investigated the potential antiviral activity of three algae powders: Chlorella vulgaris, Arthrospira maxima (Spirulina) and fucoidan purified from marine brown algae Sargassum spp. against SARS-CoV-2 infection in vitro. Vero cells were incubated with 70 µg/ml of each algae powder and either 50 or 100 TCID50/ml of SARS-CoV-2, in two types of experiments (pretreatment and simultaneous) and comparing two kinds of solvents (DMEM and DMSO). Chlorella vulgaris powder, inhibited SARS-CoV-2 infection in all assays; viral RNA was significantly reduced in supernatants at 24, 48, 72, and 96 h post-infection, the highest difference in viral load (8000-fold) was observed after 96 h. Arthrospira maxima powder inhibited SARS-CoV-2 infection using 50 TCID50/ml for both experimental schemes, but protection percent was lower when viral inoculum was increase to 100 TCID50/ml; viral RNA decreased 48 h after infection, reaching a 250-fold difference at 72 h. Fucoidan powder partially inhibited SARS-CoV-2 infection since no CPE was observed in 62.5% of trated cultures in DMEM, but the antiviral activity was increased to 100% of protection when DMSO was used as solvent. All the algae samples showed high antiviral activity against SARS-CoV-2 with a SI above of 18. These results suggest that all three algae samples are potential therapeutic candidates for the treatment of COVID-19.


Subject(s)
COVID-19 , Chlorella vulgaris , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Chlorocebus aethiops , Dimethyl Sulfoxide , Humans , Powders , RNA, Viral , SARS-CoV-2 , Solvents , Vero Cells
13.
J Nat Prod ; 85(11): 2583-2591, 2022 Nov 25.
Article in English | MEDLINE | ID: covidwho-2062146

ABSTRACT

Dihydromaniwamycin E (1), a new maniwamycin derivative featuring an azoxy moiety, has been isolated from the culture extract of thermotolerant Streptomyces sp. JA74 along with the known analogue maniwamycin E (2). Compound 1 is produced only by cultivation of strain JA74 at 45 °C, and this type of compound has been previously designated a "heat shock metabolite (HSM)" by our research group. Compound 2 is detected as a production-enhanced metabolite at high temperature. Structures of 1 and 2 are elucidated by NMR and MS spectroscopic analyses. The absolute structure of 1 is determined after the total synthesis of four stereoisomers. Though the absolute structure of 2 has been proposed to be the same as the structure of maniwamycin D, the NMR and the optical rotation value of 2 are in agreement with those of maniwamycin E. Therefore, this study proposes a structural revision of maniwamycins D and E. Compounds 1 and 2 show inhibitory activity against the influenza (H1N1) virus infection of MDCK cells, demonstrating IC50 values of 25.7 and 63.2 µM, respectively. Notably, 1 and 2 display antiviral activity against SARS-CoV-2, the causative agent of COVID-19, when used to infect 293TA and VeroE6T cells, with 1 and 2 showing IC50 values (for infection of 293TA cells) of 19.7 and 9.7 µM, respectively. The two compounds do not exhibit cytotoxicity in these cell lines at those IC50 concentrations.


Subject(s)
Antiviral Agents , Azo Compounds , COVID-19 , Influenza A Virus, H1N1 Subtype , SARS-CoV-2 , Streptomyces , Humans , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Azo Compounds/chemistry , Azo Compounds/metabolism , Azo Compounds/pharmacology , Heat-Shock Response , HEK293 Cells , Influenza A Virus, H1N1 Subtype/drug effects , Influenza, Human/drug therapy , Madin Darby Canine Kidney Cells , Orthomyxoviridae Infections/drug therapy , SARS-CoV-2/drug effects , Streptomyces/chemistry , Streptomyces/metabolism , Vero Cells , Chlorocebus aethiops , Dogs
14.
Front Immunol ; 13: 967051, 2022.
Article in English | MEDLINE | ID: covidwho-2043445

ABSTRACT

Background: BBIBP-CorV and CoronaVac inactivated COVID-19 vaccines are widely-used, World Health Organization-emergency-listed vaccines. Understanding antibody level changes over time after vaccination is important for booster dose policies. We evaluated neutralizing antibody (nAb) titers and associated factors for the first 12 months after primary-series vaccination with BBIBP-CorV and CoronaVac. Methods: Our study consisted of a set of cross-sectional sero-surveys in Zhejiang and Shanxi provinces, China. In 2021, we enrolled 1,527 consenting 18-59-year-olds who received two doses of BBIBP-CorV or CoronaVac 1, 3, 6, 9, or 12 months earlier and obtained blood samples and demographic and medical data. We obtained 6-month convalescent sera from 62 individuals in Hebei province. Serum nAb titers were measured by standard micro-neutralization cytopathic effect assay in Vero cells with ancestral SARS-CoV-2 strain HB01. We used the first WHO International Standard (IS) for anti-SARS-CoV-2 immunoglobulin (NIBSC code 20/136) to standardized geometric mean concentrations (IU/mL) derived from the nAb geometric mean titers (GMT over 1:4 was considered seropositive). We analyzed nAb titer trends using Chi-square and factors related to nAb titers with logistic regression and linear models. Results: Numbers of subjects in each of the five month-groupings ranged from 100 to 200 for each vaccine and met group-specific target sample sizes. Seropositivity rates from BBIBP-CorV were 98.0% at 1 month and 53.5% at 12 months, and GMTs were 25.0 and 4.0. Respective seropositivity rates from CoronaVac were 90.0% and 62.5%, and GMTs were 20.2 and 4.1. One-, three-, six-, nine-, and twelve-month GMCs were 217.2, 84.1, 85.7, 44.6, and 10.9 IU/mL in BBIBP-CorV recipients and 195.7, 94.6, 51.7, 27.6, and 13.4 IU/mL in CoronaVac recipients. Six-month convalescent seropositivity was 95.2%; GMC was 108.9 IU/mL. Seropositivity and GMCs were associated with age, sex, and time since vaccination. Conclusions: Neutralizing Ab levels against ancestral SARS-CoV-2 from BBIBP-CorV or CoronaVac vaccination were similar and decreased with increasing time since vaccination; over half of 12-month post-vaccination subjects were seropositive. Seropositivity and GMCs from BBIBP-CorV and CoronaVac six and nine months after vaccination were similar to or slightly lower than in six-month convalescent sera. These real-world data suggest necessity of six-month booster doses.


Subject(s)
COVID-19 Vaccines , COVID-19 , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19/therapy , Chlorocebus aethiops , Cross-Sectional Studies , Humans , Immunization, Passive , SARS-CoV-2 , Vaccination , Vero Cells
15.
Vet Microbiol ; 273: 109544, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2028561

ABSTRACT

Autophagy-related 4B (ATG4B) is found to exert a vital function in viral replication, although the mechanism through which ATG4B activates type-I IFN signaling to hinder viral replication remains to be explained, so far. The current work revealed that ATG4B was downregulated in porcine epidemic diarrhea virus (PEDV)-infected LLC-PK1 cells. In addition, ATG4B overexpression inhibited PEDV replication in both Vero cells and LLC-PK1 cells. On the contrary, ATG4B knockdown facilitated PEDV replication. Moreover, ATG4B was observed to hinder PEDV replication by activating type-I IFN signaling. Further detailed analysis revealed that the ATG4B protein targeted and upregulated the TRAF3 protein to induce IFN expression via the TRAF3-pTBK1-pIRF3 pathway. The above data revealed a novel mechanism underlying the ATG4B-mediated viral restriction, thereby providing novel possibilities for preventing and controlling PEDV.


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Animals , Chlorocebus aethiops , Coronavirus Infections/veterinary , Porcine epidemic diarrhea virus/genetics , Signal Transduction , Swine , TNF Receptor-Associated Factor 3/genetics , Vero Cells , Virus Replication
16.
Chem Biodivers ; 19(10): e202200632, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2027319

ABSTRACT

The current pandemic threat presented by viral pathogens like SARS-CoV-2 (COVID-19) suggests that virus emergence and dissemination are not geographically confined. As a result, the quest for antiviral agents has become critical to control this pandemic. In the current study, we provide a novel family of spirocyclic thiopyrimidinone derivatives whose cytotoxicity and antiviral efficacy were investigated against human coronavirus 229E (HCoV-229E) as a model for the Coronaviridae family. We utilized MTT and cytopathic effect (CPE) inhibitory tests on green monkey kidney (vero-E6) cell lines. The new molecules showed varied degrees of antiviral activity against the vero-E6 cell lines with minimal cytotoxicity. With a high level of a selective index (SI=14.8), compound 9 showed outstanding inhibitory ability and could effectively suppress the human coronavirus 229E. Molecular dynamics simulation (MD) studies were performed to measure the interaction and stability of the protein-ligand complex in motion. The MD results for the most active compound 9 explored remarkable interactions with the binding pockets of the main protease (Mpro) of SARS-CoV-2 enzyme confirming the results gained from in vitro experiments. ADMET properties were also predicted for all the tested compounds. All these results demonstrated that the novel spirocyclic thiopyrimidinone derivatives would have the potential to be safe, low-cost chemical compounds that might be used as a novel therapeutic option for Coronaviridae viruses like COVID-19.


Subject(s)
COVID-19 , Coronavirus 229E, Human , Chlorocebus aethiops , Humans , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , COVID-19/drug therapy , SARS-CoV-2 , Molecular Dynamics Simulation , Ligands , Peptide Hydrolases
17.
Front Cell Infect Microbiol ; 12: 906578, 2022.
Article in English | MEDLINE | ID: covidwho-2022651

ABSTRACT

The epitranscriptomics of the SARS-CoV-2 infected cell reveals its response to viral replication. Among various types of RNA nucleotide modifications, the m6A is the most common and is involved in several crucial processes of RNA intracellular location, maturation, half-life and translatability. This epitranscriptome contains a mixture of viral RNAs and cellular transcripts. In a previous study we presented the analysis of the SARS-CoV-2 RNA m6A methylation based on direct RNA sequencing and characterized DRACH motif mutations in different viral lineages. Here we present the analysis of the m6A transcript methylation of Vero cells (derived from African Green Monkeys) and Calu-3 cells (human) upon infection by SARS-CoV-2 using direct RNA sequencing data. Analysis of these data by nonparametric statistics and two computational methods (m6anet and EpiNano) show that m6A levels are higher in RNAs of infected cells. Functional enrichment analysis reveals increased m6A methylation of transcripts involved in translation, peptide and amine metabolism. This analysis allowed the identification of differentially methylated transcripts and m6A unique sites in the infected cell transcripts. Results here presented indicate that the cell response to viral infection not only changes the levels of mRNAs, as previously shown, but also its epitranscriptional pattern. Also, transcriptome-wide analysis shows strong nucleotide biases in DRACH motifs of cellular transcripts, both in Vero and Calu-3 cells, which use the signature GGACU whereas in viral RNAs the signature is GAACU. We hypothesize that the differences of DRACH motif biases, might force the convergent evolution of the viral genome resulting in better adaptation to target sequence preferences of writer, reader and eraser enzymes. To our knowledge, this is the first report on m6A epitranscriptome of the SARS-CoV-2 infected Vero cells by direct RNA sequencing, which is the sensu stricto RNA-seq.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Bias , Chlorocebus aethiops , Humans , Nucleotides , RNA, Viral/genetics , SARS-CoV-2/genetics , Sequence Analysis, RNA , Vero Cells
18.
Altern Lab Anim ; 50(5): 339-348, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2020821

ABSTRACT

Vero cells are one of the most frequently used cell types in virology. They can be used not only as a vehicle for the replication of viruses, but also as a model for investigating viral infectivity, cytopathology and vaccine production. There is increasing awareness of the need to limit the use of animal-derived components in cell culture media for a number of reasons, which include reducing the risk of contamination and decreasing costs related to the downstream processing of commercial products obtained via cell culture. The current study evaluates the use of protein hydrolysates (PHLs), also known as peptones, as partial substitutes for fetal bovine serum (FBS) in Vero cell culture. Eleven plant-based, two yeast-based, and three casein-based peptones were assessed, with different batches evaluated in the study. We tested the effects of three concentration ratios of FBS and peptone on Vero cell proliferation, four days after the initial cell seeding. Some of the tested peptones, when in combination with a minimal 1% level of FBS, supported cell proliferation rates equivalent to those achieved with 10% FBS. Collectively, our findings showed that plant-based peptones could represent promising options for the successful formulation of serum-reduced cell culture media for vaccine production. This is especially relevant in the context of the current COVID-19 pandemic, in view of the urgent need for SARS-CoV-2 virus production for certain types of vaccine. The current study contributes to the Three Rs principle of reduction, as well as addressing animal ethics concerns associated with FBS, by repurposing PHLs for use in cell culture.


Subject(s)
COVID-19 , Peptones , Animals , Caseins , Cell Culture Techniques , Chlorocebus aethiops , Culture Media/pharmacology , Humans , Pandemics , Peptones/metabolism , Peptones/pharmacology , Protein Hydrolysates , SARS-CoV-2 , Serum Albumin, Bovine , Vero Cells
20.
J Biol Chem ; 298(8): 102190, 2022 08.
Article in English | MEDLINE | ID: covidwho-2015572

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) causes diarrhea and dehydration in pigs and leads to great economic losses in the commercial swine industry. However, the underlying molecular mechanisms of host response to viral infection remain unclear. In the present study, we investigated a novel mechanism by which RALY, a member of the heterogeneous nuclear ribonucleoprotein family, significantly promotes the degradation of the PEDV nucleocapsid (N) protein to inhibit viral replication. Furthermore, we identified an interaction between RALY and the E3 ubiquitin ligase MARCH8 (membrane-associated RING-CH 8), as well as the cargo receptor NDP52 (nuclear dot protein 52 kDa), suggesting that RALY could suppress PEDV replication by degrading the viral N protein through a RALY-MARCH8-NDP52-autophagosome pathway. Collectively, these results suggest a preventive role of RALY against PEDV infection via the autophagy pathway and open up the possibility of inducing RALY in vivo as an effective prophylactic and preventive treatment for PEDV infection.


Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Animals , Autophagy , Chlorocebus aethiops , Coronavirus Infections/veterinary , Nucleocapsid Proteins , Porcine epidemic diarrhea virus/physiology , Ribonucleoproteins , Swine , Vero Cells , Virus Replication
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