cord-001572-ap4ro5me	2015	To determine replication kinetics, the susceptible tumor cell lines were infected with Sabin poliovirus type 1 from the parental virus or virus that was passaged for 5 times on the hematopoietic cell lines at MOI 1 or MOI 0.01, and samples of the supernatant and cellular lysates were harvested at different time points. To determine whether hematopoietic cell lines can support replication of Sabin poliovirus type 1, cells were infected with an MOI of 1 and cells together with supernatant were harvested at day 3 (for all virus passages in Vero cells and for passages 3-5 on U937 cells) or day 6 after infection. In the supernatant of all cell lines tested, at day 4, a high virus titer, comparable to Sabin poliovirus type 1 replicated in Vero cells, was observed in the culture medium, indicating that virus replication was efficient during multiple rounds of replication.
cord-002935-jq1xumrh	2018	Here, we describe variable conditions tested during the development of our cell-based drug screen assays designed to identify compounds with anti-Ebola virus activity using established cell lines and human primary cells. The effect of multiple assay readouts and variable assay conditions, including virus input, time of infection, and the cell passage number, were compared, and the impact on the effective concentration for 50% and/ or 90% inhibition (EC(50), EC(90)) was evaluated using the FDA-approved compound, toremifene citrate. The CELIA was compared to the fluorescent assay (detected by regular plate reader or the HCI system) by testing the efficacy of toremifene citrate against EBOV infection in Huh 7 cells with a range of MOIs (0.1, 0.3, 1, and 3 ) at three different time points (24, 48 and 72 hpi) . The established CELIA was used to compare anti-EBOV activity of toremifene citrate in 3 different cell types, Vero E6, Huh 7 and MDMs using an MOI of 0.5 and a time point of 48 h (Fig 7) .
cord-003284-hjx2d5rq	2018	Furthermore, using this infectious clone we have generated a mutant ZIKV containing a single amino acid substitution (A175V) in the NS2A protein that presented reduced viral RNA synthesis in cell cultures, was highly attenuated in vivo and induced fully protection against a lethal challenge with ZIKV wild-type. To analyze the genetic stability of the recombinant ZIKV harboring the point mutation A175V in the coding region of the NS2A protein (rZIKV-RGN-mNS2A), total RNA was purified from Vero cells infected with viruses from passage 1 (P1) to passage 5 (P5) using the RNeasy minikit (Qiagen), according to the manufacturer''s specifications. To investigate whether the reduced RNA synthesis of rZIKV-RGN-mNS2A in Vero cells could result in viral attenuation in vivo, the ability of the mutant virus to induce pathogenesis was analyzed in A129 mice and compared with that of the parental rZIKV-RGN ( Figure 6 ).
cord-004825-cdvnqfjz	1994	The entry mechanism of Junin virus (JV) into Vero cells was studied analyzing the effect of lysosomotropic compounds and acid pH on JV infection. Vero cells grown in coverslips were infected with JV (moi 1) and 15 mM ammonium chloride was added to the culture medium after adsorption. To reinforce that the membrane fusion activity of Junin virus is expressed at low pH, the formation of JV-induced syncytia in infected Vero cells incubated in medium at pH 5.5 or 7.5 was quantitated. In fact, a bypass of the ammonium chloride block of JV infection was achieved when the extracellular medium was at a pH below 6.1 (Fig. 5) , suggesting that the acidic conditions would probably trigger direct fusion of virus envelope with the cell membrane.
cord-010369-x9z8dg6a	2020	Quantification of cellular and extracellular viral RNA revealed that high JEV production in Huh7.5.1–8 cells can be attributed to rapid viral replication kinetics and efficient virus release early in infection. Huh7.5.1-8 and Vero cells under high and low confluency were infected with JEV at MOI 0.1, and then the virus titer in culture supernatant was monitored from 1 to 4 d pi (Fig 2) . The culture supernatant of Huh7.5.1-8 cells exhibited a higher relative virus titer than that of Vero cells, particularly during the early infection times. These results suggested that the Huh7.5.1-8 cell line, compared with the Vero cell line, has a higher virus productivity and susceptibility to virus-induced cell death upon flavivirus infection. First, Huh7.5.1-8 cells produced higher amounts of infectious JEV and YFV than Vero cells early in infection (Figs 2 and 8A-8D ).
cord-023871-9vi0m378	2009	AKT and JNK (Jun NH(2)-terminal kinase) signaling pathways are important to establish persistent infection of SARS-CoV in Vero E6 cells. SARS-CoV S protein expression induces release of interleukin-8 (IL-8) via ERK and p38 MAPK signaling pathways including activator protein 1 (AP-1) in A549 cells ). SARS-CoV infection induces apoptotic cell death in Vero E6 cells, via dephosphorylation of STAT3 by p38 MAPK activation, and inactivation of Akt, as previously described. Overexpression of SARS-CoV 3a protein in Vero E6 cells induces apoptosis, mediated through a caspase-8-dependent pathway or p38 MAPK Waye et al. Overexpression of severe acute respiratory syndrome coronavirus 3b protein induces both apoptosis and necrosis in Vero E6 cells The 3a protein of severe acute respiratory syndrome-associated coronavirus induces apoptosis in Vero E6 cells Microarray and real-time RT-PCR analyses of differential human gene expression patterns induced by severe acute respiratory syndrome (SARS) coronavirus infection of Vero cells
cord-102246-2lmq9s4l	2001	title: Morphological and intracellular alterations induced by cytotoxin VT2y produced by Escherichia coli isolated from chickens with swollen head syndrome Abstract Recently, a novel verocytotoxin named VT2y was described which belongs to the STx family and is produced by Escherichia coli isolated from domestic poultry with swollen head syndrome (SHS). The VT2y toxin induced apoptosis in Vero, HeLa, CHO, CEF (primary chicken embryo fibroblast) and PCK (primary chicken kidney) cell lines. The aim of this study is to illustrate the morphological and intracellular alterations induced in vitro by cytotoxin VT2y in Vero, HeLa, CHO, HEp-2, PCK and CEF cell lines. The cytotoxin VT2y caused morphological alterations in Vero cells, such as cytoplasm vacuolization, blebbing of the plasma membrane, chromatin condensation within the nucleus, nuclear shrinkage and apoptotic bodies within 15 min. Escherichia coli strains isolated from pigs with edema disease produce a variant of Shiga-like toxin II Cytotoxin produced by Escherichia coli isolated from chickens with swollen head syndrome (SHS)
cord-253616-7jyui5ca	2020	To investigate the anti-ZIKV activity of harringtonine, we assessed the inhibition of virus infection in Vero cells with MOI = 0.01 under different concentrations of harringtonine for 48 h. Intracellular viral RNA levels, protein expression levels and virus progeny in supernatants were respectively determined by RT-qPCR, western blotting and fluorescent focus assay (FFA). The dose-dependent anti-ZIKV activities of harringtonine were observed to decrease viral RNA/protein production and progeny yield ( Figure 1B-D) , indicating that virus propagation was suppressed. Harringtonine (625 nM) was administered at different stages of ZIKV infection with MOI = 0.1, and then the levels of ZIKV RNA in cells, as well as virus titers in supernatants, were determined after 24 h treatment. Harringtonine (625 nM) was administered at different stages of ZIKV infection with MOI = 0.1, and then the levels of ZIKV RNA in cells, as well as virus titers in supernatants, were determined after 24 h treatment.
cord-254317-n2knqj4z	2018	Porcine epidemic diarrhea virus (PEDV) variants having a large deletion in the N-terminal domain of the S1 subunit of spike (S) protein were designated as S1 NTD-del PEDVs. They replicate well in experimentally infected pigs. Effect of mucin, bile and bile acids on the infection of PEDV icPC22A and icPC22A-S1Δ197 in Vero and IPEC-DQ cells Viruses (icPC22A or icPC22A-S1Δ197) were mixed with different concentrations of BM (0, 0.1, 0.3, 0.5 mg/mL) or PGM (0, 0.5, 1.0, 2.5, 5.0 mg/mL). Compared with the peak fecal PEDV N gene shedding titer (11.6 ± 0.2 log 10 copies/mL) of piglets in the icPC22A group (1 dpi), pigs in the coinfection group had a significantly higher peak titer (13.6 ± 0.7 log 10 copies/mL) ( Fig. 1B and Table 2 ) at a delayed time point (1.5 dpi). S1 NTD-del PEDV replicated to a lower peak titer in coinfection than that in single virus infection in both Vero cells and IPEC-DQ cells.
cord-254916-y1rw9q11	2020	The overall level of amino acid sequence identity of viral proteins ranges from about 65 % in the least conserved parts of the S protein to about 95 % in the most conserved replicative enzyme domains, prompting the coronavirus study group of the International Committee on the Taxonomy of Viruses to classify the new agent within the species Severe acute respiratory syndrome-related coronavirus, which also includes the 2003 SARS-CoV [1] . In this report, we describe a comparative study of the basic replication features of SARS-CoV and SARS-CoV-2 in Vero E6 cells, including growth kinetics, virus titres, plaque phenotype and an analysis of intracellular viral RNA and protein synthesis. One of them is the rapid evolution -during virus passaging in Vero cells -of a specific region of the SARS-CoV-2 S protein that contains the so-called furin-like cleavage site.
cord-256370-cz88t29n	2016	This is the first report on isolation of an orthoreovirus from an arthropod host associated with bats, and phylogenetic and sequence data suggests that MAHLV constitutes a new species within the Orthoreovirus genus. Maximum Likelihood trees were prepared using amino acid sequences of all open reading frames from all segments, showing the placement of Mahlapitsi virus (MAHLV) in the Orthoreovirus genus relative to other viruses in this genus for which sequence is available on Genbank. A Maximum Likelihood tree, constructed with nucleic acid sequence data for the RNA-dependent RNA polymerase (RdRp) encoding segments of representative viruses from the different genera within Reoviridae (Figure 7) shows the placement of both isolates amongst other orthoreoviruses in the family. Maximum Likelihood trees were prepared using the deduced amino acid sequences from the open reading frames (ORF''s) of all the virus'' segments and those of other viruses in the Orthoreovirus genus (Figures 8-10) .
cord-260107-gqbtkf0x	2015	In the present study, one Korean PEDV strain, KOR/KNU-141112/2014, was successfully isolated and serially propagated in Vero cells for over 30 passages. Our genomic analyses indicated that the Korean isolate KNU-141112 is genetically stable during the first 30 passages in cell culture and is grouped within subgroup G2b together with the recent re-emergent Korean strains. Our data indicated that KNU-141112 isolate is relatively stable during the first 30 passages in cell culture and is classified into subgroup G2b that includes PEDV strains responsible for recent severe outbreaks in Korea and the US. Although virus isolation in cell culture from clinical samples of naturally or experimentally infected pigs is fastidious, recent studies reported the successful isolation and propagation of several US original PEDV strains using Vero cells (Chen et al., 2014; Oka et al., 2014) . Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene
cord-263178-lvxxdvas	2018	To study the roles of hypervariable regions (HVRs) in receptor-binding subunit S1 of the spike protein, we manipulated the genome of the IBV Beaudette strain using a reverse genetics system to construct seven recombinant strains by separately or simultaneously replacing the three HVRs of the Beaudette strain with the corresponding fragments from a QX-like nephropathogenic isolate ck/CH/LDL/091022 from China. We could not detect the replication with ck/CH/ LDL/091022 in Vero cells, so the neutralization tests were performed in 9-day-old SPF embryonated eggs to confirm whether the serotypes of the recombinant IBVs belonged to ck/CH/LDL/091022. Viral antigen was observed in Vero cells infected with the Beaudette strain and the seven recombinant IBVs (Fig. 1b) . S1 gene sequencing results confirmed that the heterogenous HVRs were stably maintained in the recombinant IBVs (Sup Fig. 1) , and no additional mutations were detected in the S protein after three passages in cells or eggs.
cord-263439-oquk4t96	2014	Similar to other coronaviruses, PEDV spike protein mediates its cell entry by binding to cellular receptors and inducing membrane fusion between viral envelopes and cellular membranes. Taken together, our findings reveal that PEDV enters Vero cells via clathrin-mediated endocytosis and requires serine proteolysis during infection. Based on these observations, we concluded that an exogenous protease, like trypsin, was necessary to induce cell-cell fusion in PEDV-infected Vero cells but not essentially required for virus-cell entry. So, we hypothesized that PEDV entry into Vero cells under the trypsin-free condition most likely occurred inside endosomal compartments where cellular proteases might operate similar to trypsin, facilitating S-mediated fusion of PEDV with the endosomal membrane. The infection inhibition assay using various substrates that interfere with endocytosis or lysosomotropic agents revealed that PEDV enters Vero cells via clathrin-mediated endocytic uptake and delivery of virus to an acidic intracellular compartment.
cord-265263-r9e6bop3	2015	Tested lactobacilli displayed anti-HSV-2 activity when they were co-incubated with the virus prior to inoculating the mixture to Vero cell monolayers. This study shows that antiviral activity is due to the direct interaction between probiotic strains and enveloped virus. plantarum CMUL140 strain with HSV-2 on Vero cell monolayers has increased the cells viability by 65, 35 and 15 %, respectively, as compared to the control with 22 % viability, after exposure to the virus (Fig. 3a) . plantarum CMUL140-derived neutralized supernatants enhanced slightly the viability of Vero cell monolayer inoculated with 100 PFU HSV-2 with about 9.5, 5.4 and 2.4 %, respectively, due to reduction in viral infectious particles. gasseri CMUL57 at 10 8 CFU/ml or Dulbecco''s Modified Eagle''s Medium (DMEM, negative control) were incubated for 2 h at 37 °C in CO 2 atmosphere in the presence of HSV-2 (10 4 PFU/ml) or CVB4E2 (10 3 TCID 50 /ml).
cord-266585-jfjrk9gy	2007	During construction of an infectious clone from a Vero cell-adapted coronavirus infectious bronchitis virus (IBV), we found that a G–C point mutation at nucleotide position 15526, causing Arg-to-Pro mutation at amino acid position 132 of the helicase protein, is lethal to the infectivity of IBV on Vero cells. Further characterization of the in vitro-synthesized full-length transcripts containing the G15526C mutation demonstrated that this mutation blocks the transcription of subgenomic RNAs. Substitution mutation of the Arg132 residue to a positively charged amino acid (Lys) affected neither the infectivity of the in vitro-synthesized transcripts nor the growth properties of the rescued virus. To further demonstrate that the failure to rescue infectious virus from the G15526C mutant transcripts is due to a defect in subgenomic RNA transcription, the full-length clones with and without the G15526C mutation were used to generate recombinant IBV expressing the enhanced green fluorescent protein (EGFP) by replacing the 5a gene with EGFP.
cord-267446-rpv19oy6	2011	The addition of trypsin was shown to induce fusion of the infected Vero cells, resulting in the formation of multiple syncytia, and produced a significant increase in virus titer after several passages. For example, infection by severe acute respiratory syndrome coronavirus (SARS-CoV) and murine hepatitis virus strain 2 (MHV-2) requires proteolytic cleavage in their target cells, which is mediated by trypsin-like proteases [24, 29, 32] . To investigate the effects of proteolytic cleavage of the surface protein of Vero cells and free virions by trypsin, Vero cells or KPEDV-9 were pre-treated with trypsin prior to infection. These results are consistent with the suggestion that trypsin is not absolutely essential for Vero-cell-adapted PEDV infection, as reported for other group 1 coronaviruses, but the titer increases during infection with trypsin-treated virus.
cord-267613-hsc2x36j	2020	Moreover, we found 9 drugs are antiviral in lung cells, 7 of which have been tested in humans, and 3 are FDA approved including Cyclosporine which we found is targeting Cyclophilin rather than Calcineurin for its antiviral activity. Previous studies found that the antiviral drug remdesivir, which was developed against the RNA-dependent RNA polymerase of Ebola virus, was also active against SARS-CoV-2 in vitro, with promising results in clinical trials (5) (6) (7) . Both cepharanthine and tetrandrine were previously shown to have antiviral activity against the human coronavirus OC43 and in recent studies on SARS-CoV-2 in Vero cell screens (13, 62, 63) . Strikingly, the activities of all of these drugs is similar in the two cell lines suggesting the same target and mechanism-of-action and that Cyclosporine would block SARS-CoV-2 in diverse infected tissues in vivo.
cord-270683-982eqtog	2020	We determined that the Vero E6 and MA-104 cell lines are suitable for supporting SARS-CoV-2 that supports viral replication, development of cytopathic effect (CPE) and subsequent cell death. Phylogenetic analyses of the whole genome sequences showed that the hCoV-19/Turkey/ERAGEM-001/2020 strain clustered with the strains primarily from Australia, Canada, England, Iran and Kuwait and that the cases in the nearby clusters were reported to have travel history to Iran and to share the common unique nucleotide substitutions. For whole genome sequencing of hCoV-19/Turkey/ERAGEM-001/2020, Vero E6 cells infected with the virus were used for RNA extraction. The growth kinetics study showed that SARS-CoV-2 replicated rapidly and efficiently and could be detected within 6 h post-infection in Vero E6 and MA-104 cells (Fig 6A and 6B ). Immunoblotting analysis also confirmed that only Vero E6 and MA-104 cell lines infected with SARS-CoV-2 showed the expression of the virus specific proteins expression (Fig 5) .
cord-271638-0wsyl7vk	2020	Therefore, the natural dietary flavonoid myricetin has potential to be developed into a novel anti-HSV agent targeting both virus gD protein and cellular EGFR/PI3K/Akt pathway. As shown in Fig. 2C and E, myricetin treatment (20 μM) during adsorption significantly decreased the fluorescence of ICP5 protein on cell surface, compared to that in non-treated virus control cells, suggesting that myricetin may block virus adsorption process of HSV. As shown in Fig. 3A , in HSV-2 (MOI = 3.0) infected Vero cells, obvious syncytia with multinuclear cells were observed in non-treated virus control group (HSV-2) at 7 h p.i. However, treatment with myricetin (30, 15 μM) during 5-7 h p.i. markedly blocked syncytium formation only with a limited number of small syncytia, suggesting that myricetin may inhibit HSV-induced cell fusion. However, myricetin (2.5, 5, 10, 20 μM) treatment did not significantly influence the total expression levels of EGFR, PI3K and Akt proteins in HSV-2 infected Vero cells (Fig. 4G and H) .
cord-272729-nbgdmavr	2012	Investigations into the mechanism of action of ribavirin against PRRSV and PEDV revealed that the addition of guanosine to the ribavirin treatment significantly reversed the antiviral effects, suggesting that depletion of the intracellular GTP pool by inhibiting IMP dehydrogenase may be essential for ribavirin activity. Further experiments revealed that suppression of ribavirin affects post-entry steps of the replication cycle of PRRSV and PEDV, including viral genomic and sg RNA synthesis, viral protein expression, and virus production. Several mechanisms of action for the antiviral activity of ribavirin have been suggested, including a reduction in cellular GTP pools via inosine monophosphate dehydrogenase (IMPDH) inhibition and increased mutation frequency on the virus genome leading to error catastrophe (Graci and Cameron, 2006) . Treatment of cells with ribavirin resulted in significant attenuation of postentry steps during the replication of porcine nidovirus, as determined by lower progeny production, diminished viral protein expression, and decreased synthesis of genomic RNA and sg mRNA.
cord-273745-mwjh5se7	2014	Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. When Vero cells were pre-treated with peptide (cell pretreatment assay) prior to virus infection (Fig. 1B) , little changes in virus titers were observed between the control and peptide treatment groups; some small effects were observed with the rabbit anti-PEDV neutralizing antibodies. Finally, in the virus pretreatment assays where PEDV was incubated with peptides prior to cell infection (Fig. 1C) , the results indicated that both peptides H and S inhibited PEDV infectivity where EC 50 values were approximately 1 μg/ml and 62.5 μg/ml, respectively. Results clearly show that peptide H had no demonstrable effects on TGEV or PrV even at very high peptide concentrations (1 mM/ml) (Fig. 3) suggesting that a non-specific reactivity with virus envelopes is unlikely to be the cause for attenuating PEDV infectivity.
cord-274110-nyyunoha	2010	A cDNA comprising the complete genome of West Nile Virus (WNV) was generated by chemical synthesis using published sequence data, independent of any preformed viral components. The synthetic WNV, produced by transfection of in vitro transcribed RNA into cell culture, exhibited undistinguishable biological properties compared to the corresponding animal-derived wild-type virus. Taking advantage of the rapid progression of gene synthesis technology (for review [24] ), we intended to adopt such a synthetic approach to produce a flavivirus cDNA system for the generation of a synthetic WNV seed virus for use in vaccine development. The production and characterization of the resulting West Nile Virus, which fully matched the sequence of the in silico designed viral genome, confirms the feasibility and accuracy of the synthetic flavivirus reverse genetic system. Cover slips with fixed cells were dried, rehydrated with phosphate-buffered saline and treated with a polyclonal mouse anti-WNV serum (1:50 dilution) obtained after immunization of mice with a formalin-inactivated whole virus vaccine preparation.
cord-275863-qos9vu3r	2011	In this report we have studied the interaction of dengue viruses produced in insect cells, tumor cell lines, and primary human dendritic cells (DCs) with DC-SIGN and L-SIGN. To formally prove that the loss of infection of DCs was a result of the loss of affinity of DC-produced virus for DC-SIGN, we went on to test infection on 3T3 cells expressing DC-SIGN and included in these assays the related C-type lectin L-SIGN ( Figure 3A ), which has also been reported to be a receptor for dengue virus. C6/36-and DC-derived viruses were incubated with increasing levels of pooled convalescent dengue immune serum and subsequently used to infect U937, a monocyte cell line that expresses the Fc receptor and which shows relatively low infectivity without the presence of enhancing antibodies. Viruses produced in both DCs and insect cells were susceptible to enhancement, over the same range of antibody concentrations, showing that DC-produced virus could exploit ADE to replicate in individuals undergoing a secondary dengue infection ( Figure 6A ).
cord-276361-77cylm1o	2004	title: HIV protease inhibitor nelfinavir inhibits replication of SARS-associated coronavirus Here we report that the HIV-1 protease inhibitor, nelfinavir, strongly inhibited replication of the SARS coronavirus (SARS-CoV). Experiments with various timings of drug addition revealed that nelfinavir exerted its effect not at the entry step, but at the post-entry step of SARS-CoV infection. We found that nelfinavir, a widely used HIV-1 protease inhibitor, could inhibit SARS-CoV replication efficiently. We screened our chemical library and found that nelfinavir could inhibit SARS-CoV replication in Vero E6 cells. Nelfinavir clearly inhibited the cytopathic effect (CPE) induced by infection with SARS-CoV (Fig. 1A) . Nelfinavir significantly inhibited SARS-CoV replication when used before infection (Figs. The other protease inhibitors including ritonavir had no effect on replication of SARS-CoV CC 50 , cytotoxic concentration of the compound that reduced cell viability to 50%. Our studies have clearly shown that nelfinavir can strongly inhibit the replication of SARS-CoV in Vero E6 cells.
cord-277547-2vim1wno	2011	In the present study, antiviral activity of four types of bioflavonoid against dengue virus type -2 (DENV-2) in Vero cell was evaluated. Daidzein showed a weak anti-dengue activity with IC(50 )= 142.6 μg mL(-1 )when the DENV-2 infected cells were treated after virus adsorption. Although there was no significant direct virucidal activity against DENV-2 by quercetin, continuous treatment of cells from 5 h before virus infection up to 4 days post-infection exhibited anti-dengue activity with IC 50 = 28.9 μg mL -1 (Figure 3a) . There was no significant change in the antiviral activity of daidzein when cells were treated continuously from 5 h before virus infection up to 4 days post infection comparing to its anti-dengue activity for postadsorption treatment (Figure 1 ). To investigate which of the many flavonoids could affect DENV infection, in the present study, we examined the potential effects of quercetin, naringin, hesperetin and daidzein on dengue virus infection of Vero cells.
cord-279316-xz7aawem	2007	Recent studies regarding SARS and SARS‐CoV have clarified that activation of mitogen‐activated protein kinases (MAPKs) plays important roles in upregulation of cytokine expression and apoptosis both in vitro and in vivo. For example, mitogen-activated protein kinases (MAPKs) are well-known signal transducers that respond to extracellular stimulation by cytokines, growth factors, viral infection, and stress, and in turn regulate cell differentiation, proliferation, survival, and apoptosis. Extracellular signal-regulated kinase (ERK) 1/2 was phosphorylated in SARS-CoV-infected Vero E6 cells, 27 whereas ERK1/2 was downregulated in N protein-expressing COS-1 cells as described below. Activation of the p38 MAPK signaling pathway and dephosphorylation of STAT3 via p38 MAPK induced by SARS-CoV infection have partially proapoptotic roles in Vero E6 cells. Importance of Akt signaling pathway for apoptosis in SARS-CoV-infected Vero E6 cells
cord-279975-542qbbgp	2000	title: Isolation of porcine epidemic diarrhea virus in porcine cell cultures and experimental infection of pigs of different ages This paper describes the isolation of porcine epidemic diarrhea (PED) virus in Vero and porcine cell cultures, and the influence of age on disease in experimental infection. PED virus was isolated from the small intestine of piglets inoculated with PED samples and cultured in Vero, porcine bladder and kidney cells propagated in collagen-coated tissue culture plates in maintenance medium (MM) containing trypsin. In porcine bladder and kidney cell cultures inoculated with isolated PED virus, cytopathic effects (CPE) including cell fusion were detected. Isolation of porcine epidemic diarrhea virus in porcine cell cultures and experimental infection of pigs of different ages Upon experimental infection, 2-and 7-day old pigs inoculated with PED virus developed severe diarrhea and died.
cord-283309-ovx5fzsg	2019	Six subgenomic mRNAs containing the leader-body junction sites, including a bicistronic mRNA encoding the accessory NS7a and NS7b genes, were experimentally identified in SeACoV-infected cells. Anti-Ac (Nsp3) staining also resulted in detection of perinuclear foci at four time points, indicating localization to the viral replication-transcription complexes (Fig. 1C) , which was similar to the pattern of Nsp3 antibody observed in SARS-CoV-infected Vero cells (Prentice et al., 2004) . DMVs are membrane structures where viral genomic RNA is recognized by the host cell machinery and translated into non-structural proteins (ORF1ab), assembling into viral replication-transcription complexes (Gosert et al., 2002) , whereas LVCVs are large circular organelles that are thought to originate from Golgi compartments expanding to accommodate numerous precursor virions Positions of forward (LF) and reverse primers (S1-R, sgORF3-R, sgE-R, sgM-R, sgN-R and NS7a-R/NS7-R) used for PCR amplification of distinct subgenomic mRNAs (sgRNAs) are indicated by arrows under the genome.
cord-284322-synuzaxm	2010	To confirm these initial observations, we established a cell culture model of mixed infections with Chlamydia and a cell culture-adapted porcine epidemic diarrhea virus (ca-PEDV) and hypothesized that this would result in the generation of persistent chlamydial forms. In contrast, dual infections with ca-PEDV and Chlamydia pecorum resulted in the exclusive production of aberrant inclusions containing between 2-50 ABs. Chlamydial inclusions in viral syncytia grew even larger than in non-viral infected Vero cells. The changes of chlamydial inclusion size by subsequent virus addition to Chlamydia abortus are different to those we observed in the Chlamydia pecorum dual infection experiments. TEM examinations of mixed infections (ca-PEDV and Chlamydia abortus or Chlamydia pecorum) revealed aberrant chlamydial inclusions containing fewer bacteria than typical inclusions and were located in viral syncytia or single cells without viral infection. Enlarged chlamydial inclusions were described in that study in the ca-PEDV co-infection model with Chlamydia abortus and Chlamydia pecorum but no further ultrastructural analysis has been subsequently performed.
cord-287488-h102xn29	2020	BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed in Brazil in February 2020, the first cases were followed by an increase in the number of cases throughout the country, resulting in an important public health crisis that requires fast and coordinated responses. METHODS: After diagnosis in patients that returned from Italy to the São Paulo city in late February by RT-PCR, SARS-CoV-2 isolates were obtained in cell cultures and characterised by full genome sequencing, electron microscopy and in vitro replication properties. FINDINGS: The virus isolate was recovered from nasopharyngeal specimen, propagated in Vero cells (E6, CCL-81 and hSLAM), with clear cytopathic effects, and characterised by full genome sequencing, electron microscopy and in vitro replication properties. Virus stocks viable (titre 2.11 × 10(6) TCID50/mL, titre 1.5 × 10(6) PFUs/mL) and inactivated from isolate SARS.CoV2/SP02.2020.HIAE.Br were prepared and set available to the public health authorities and the scientific community in Brazil and abroad.
cord-288644-ywaefpe8	2020	We have tested the antiviral activity of different clinically available compounds and their combinations by assessing their ability to inhibit viral induced cytopathic effect in vitro. Drug selection criteria first focused on compounds already being tested in clinical trials, along with well-known human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV) protease inhibitors, as well as other compounds suggested to have potential activity against SARS-CoV-2 in molecular docking analysis or in vitro assays. Additional Food and Drug Administration (FDA)-approved compounds previously used to abrogate viral entry via clathrin-mediated endocytosis were also tested in this SARS-CoV-2-induced cytotoxicity assay (Supp . Cytopathic effect on Vero E6 cells exposed to a fixed concentration of SARS-CoV-2 in the presence of increasing concentrations of plitidepsin and its combinations with hydroxychloroquine and remdesivir.
cord-289248-6mx4o0eb	2018	These two mutants grew to high titer in Vero cells, were genetically stable, and were significantly more attenuated in vitro and in vivo compared to the parental rMV-Hu191 vaccine strain. We next compared the replication kinetics of the rMV-Hu191 mutants and the parental virus in Vero cells in the time course of 120 h after infection (Fig. 5 ). These data suggest that rMVs carrying mutations in the SAM binding site were more attenuated in Vero cells than the parental MV vaccine strain. In this study, we successfully generated two recombinant measles viruses with amino acid substitutions in the SAM binding site of L protein and examined the effects of these mutations on viral replication, safety, and immunogenicity. We generated two recombinant MV-Hu191 carrying mutations in the SAM binding site, which not only grew to high titer in Vero cells and were genetically stable but also were significantly more attenuated and immunogenic compared to the currently used Chinese MV vaccine strain.
cord-295559-yc8q62z8	2013	Coronavirus S proteins are Class I viral fusion proteins like the HIV envelope (env), influenza hemagglutinin (HA) and paramyxovirus fusion (F) glycoproteins [17] , which typically require protease cleavage between the S1 and S2 domains ( Figure 1A ) to permit conformational changes in S2, activated by receptor binding and/or low pH, that mediate membrane fusion leading to virus entry and syncytia formation [3, 17, 18] . In addition to entry by endocytosis, we showed that, like SARS-CoV [21, 22] , MERS pseudovirions could enter susceptible Vero E6 cells at the plasma membrane if virions were first bound to cell surface receptors at 4°C at neutral pH in the presence of NH 4 Cl to inhibit acidification of endosomes, and also treated briefly at room temperature with trypsin to cleave the viral S protein.
cord-297531-et1sli23	2017	Our current investigation found a mAb, m27f that recognizes a new continuous epitope (residues 292 to 297) within the pro-fusion domain of HSV and possesses a high level of virus-neutralizing activity. Briefly, virusantibody mixture was incubated for 1 h at 4°C before inoculating over the Vero cells (pre-attachment), while prechilled (4°C for 15 min) Vero cells were infected with HSV-1 or HSV-2 (100 pfu/well) at 4°C for 1 h to allow virus adsorption before serial dilutions of antibodies were added (post-attachment). After 2 h of adsorption at 37°C, the virus inoculum was removed and cells were washed with PBS twice then incubated in DMEM containing 2% FBS in the presence of antibodies, m27f (500 μg/ml) and 21C11 (500 μg/ml), mouse IgG (500 μg/ml), or medium alone as a control. As shown in Fig. 4A , m27f completely inhibited cell-to-cell spread of both HSV-1 and HSV-2, as evidenced by observing the limited fluorescence caused by virus infection.
cord-298922-k568hlf4	2015	Among the disease-related functions, certain anti-viral pathways and proteins, such as the RIG-I-like receptor, Rap1, autophagy, mitogen-activated protein kinase, PI3K-Akt and Jak-STAT signaling pathways, and integrin β2/β3 and cystatin-C proteins, represented potential factors in PEDV infection. In our current study, we used a quantitative proteomics approach based on an iTRAQ tandem mass spectrometry (MS/MS) technique to identify proteins differentially expressed between PEDV-infected and mock-infected Vero E6 cells. To verify the differential expression of the selected DEPs, equivalent volumes of the cell lysate replicates from the PEDV-infected (V1-V3) and mock-infected (C1-C3) Vero E6 cells were pooled into the V and C samples, respectively, and western blotting was performed as described above, with the following exceptions: a 1:1000 dilution of the polyclonal antibodies anti-␤ tubulin, anti-integrin-␤3, anti-cystatin-C, anti-protein S100-A2, anti-apolipoprotein E4, and anti-centrin from rabbit (Beijing Biosynthesis Biotechnology, Beijing, China) was used as the primary antibody, and a 1:5000 dilution of the HRP-conjugated goat anti-rabbit IgG (Sigma-Aldrich, St. Louis, USA) was used as the secondary antibody.
cord-299509-7xjdryoq	2013	Infectious cDNA clones of viruses have become invaluable tools that allow reverse genetics studies to elucidate the contribution of specific amino acids or RNA structures to viraemia, virulence, antigenicity, replication kinetics, interactions with host factors, adaptation to new vectors, and many other aspects of the viral life cycle. To obtain a virus that -in terms of virulence, sensitivity to antiviral compounds, and CHIKV-host interactions -is expected to have the general characteristics of the E1-226V CHIKV strains that were circulating during the 2005-2009 outbreaks, we have constructed a completely synthetic CHIKV cDNA clone based on the consensus sequence of the aligned genomes of these recent isolates. Indirect immunofluorescence analysis of Vero E6 cells infected with CHIKV LS3, LS3-GFP, or ITA07-RA1 at various time points showed that the localization and expression kinetics of E2 and dsRNA were similar for the natural isolate and the synthetic viruses (Fig. 6) .
cord-300379-db79kb5c	2019	To quantify the ability of ATA to prevent ZIKV-induced apoptosis, tissue culture supernatants from ZIKV-infected Vero and A549 cells were harvested at 24, 48, and 72 h p.i. to measure the level of apoptotic signal as determined by caspase 3 and 7 activities ( Figure 5B) . ZIKV-infected cells showed FIGURE 4 | Aurintricarboxylic acid inhibition of ZIKV replication: Vero (A) and A549 (B) cells (24-well plate format, 2.5 × 10 5 cells/well, triplicates) were infected (MOI 0.1) with Paraiba/2015. In this study, we demonstrated that ATA (Figure 1 ) has limited toxicity (Figure 2) and an effective and dose-dependent antiviral activity against ZIKV infection (Figures 3, 4) in both monkey kidney epithelial Vero and human alveolar A549 cells. Notably, ATA can prevent ZIKV-induced CPE and apoptosis in both cell lines ( Figure 5 ) and has broad anti-viral activity against representative ZIKV strains from the African (Uganda/1947 and Nigeria/1968) and the Asian/American (Puerto Rico/2015 and French Polynesia/2013) lineages (Figure 6) .
cord-305496-t8ykkekl	2020	One such tool for evaluating neutralizing antibody response is a 88 plaque/focus neutralization reduction test (PRNT/FRNT), which evaluates the ability of polyclonal 89 sera samples to prevent or reduce infection of a cell monolayer in vitro. We examined the impact of cell density on foci formation for both Vero WHO and Vero E6 cells 144 by plating identical dilutions of SARS-CoV-2 virus stocks on 96-well plates seeded with differing 145 numbers of WHO or E6 cells (3 × 104, 1.5 × 104 or 3 × 104 cells/well) one day prior to infection 146 of the cell monolayer. To determine the optimal time frame for infection of SARS-CoV-2 on a Vero WHO cell 172 monolayer to form individual foci, we tested a variety of incubation times. The FFA relies on an immunostaining protocol of an infected cell monolayer in order to 197 quantify infectious virus titer and is therefore dependent upon SARS-CoV-2-specific antibody 198
cord-309469-2naxn580	2019	For example, polyadenylated nuclear (PAN) RNA encoded by Kaposi''s sarcoma-associated herpesvirus (Sun et al., 1996; Zhong and Ganem, 1997) , the~2-kb latency-associated transcript (LAT) expressed by Herpes simplex virus (Bloom, 2004 ), a con-served~5-kb intron expressed by Human cytomegalovirus (hCMV) (Kulesza and Shenk, 2004) , and a 7.2-kb RNA expressed by mouse CMV (Kulesza and Shenk, 2006) , U-rich RNAs (HSURs) produced by Herpesvirus saimiri (HVS), (Albrecht and Fleckenstein, 1992; Ensser and Fleckenstein, 2005) ; (3) Subgenomic ncRNAs from single-stranded RNA viruses by incomplete degradation of genomic RNA by the cellular 5-3′ exonuclease XRN1. The results confirmed previous report that IBV can synthesize sgRNA via template switch mediated by a noncanonical core sequence (Bentley et al., 2013) Notably, the mutant virus carrying four mutations (A27100U/A27111U/G27113C/G27114C) was also unable to produce ncRNA (Fig. 4) , suggesting these nucleotides are required for ncRNA production.
cord-309934-kcyao9i9	2004	Here we report that certain interferon subtypes exhibit in vitro inhibitory activity against SARS-CoV and are candidates for follow-up studies in animal models and patients to determine their efficacy in vivo. A collection of 19 antiviral drugs was tested in the SARS-CoV CPE inhibition assay ( Table 2) . Because the criteria for ascertaining anti-SARS-CoV activity in this screen were set at 100% inhibition of CPE, and as high doses of interferons may result in severe clinical side effects, we chose to conduct further evaluations only in the interferons that showed complete inhibition from initial screen, namely, Wellferon, Multiferon, Betaferon, and Alferon. Betaferon, Alferon, Multiferon, Wellferon, and ribavirin inhibited CPE in SARS-CoV-infected Vero E6 cells, in decreasing order of potency. Ribavirin, a drug widely used in initial efforts to manage SARS infections, inhibited CPE completely at 500-5,000 µg/mL at virus loads of 100-10,000 PFU per well.
cord-312899-ot5pvtbl	2004	Commercial antiviral agents and pure chemical compounds extracted from traditional Chinese medicinal herbs were screened against 10 clinical isolates of SARS coronavirus by neutralisation tests with confirmation by plaque reduction assays. Interferon-beta-1a, leukocytic interferon-alpha, ribavirin, lopinavir, rimantadine, baicalin and glycyrrhizin showed antiviral activity. We report in this study on the in vitro antiviral susceptibility of 10 isolates of SARS coronavirus to commercially available antiviral agents and pure chemical compounds including baicalin, glycyrrhizin, and chlorogenic acid extracted from traditional Chinese herbs. Further testing by neutralization tests Table 3 Comparison of antiviral activity of 10 compounds against 10 strains of SARS-CoV in fRhK4 cell line, against the prototype strains (39849) with the other 9 isolates of SARS coronavirus against the active compounds confirmed detectable inhibitory activities for leukocytic interferon-alpha, interferon-beta-1a, ribavirin, lopinavir, rimantadine, and baicalin.
cord-313596-kc8loqyj	2014	Detection of genomic rearrangements in the Vero JCRB0111 cell line Copy number variants were detected using the Control-FREEC software 32 with a 100-kb window size and 20-kb step size. To characterize SNVs in the Vero cell line nuclear genome, we mapped our paired-end reads to the reference genome of the rhesus macaque (M. Analysis of collected SRV-related short reads from all paired-end short reads of the Vero JCRB0111 cell line, followed by analyses of gene assignment and long terminal repeat (LTR) finding, identified the 8,367 bp complete SRV genome sequence. SRV variant sequences lacking the U3 and R regions of 3 0 LTR were instead detected in Vero ATCC CCL81-associated SRV, 47 while the results of this study suggested that some SRV copies in the Vero JCRB0111 cell genome were defective in the env-3 0 LTR region (Fig. 4) .
cord-314546-fbddxbhd	2020	Although nafamostat mesylate and camostat mesylate were not selected as potent antiviral drug candidates in our earlier study, we compared the antiviral efficacy of these drugs at this time in between Vero and Calu-3 cells following the discovery that TMPRSS2, a host protease necessary for priming viral spike glycoprotein, could be a target for COVID-19 antiviral development. 11 The discrepancy in IC 50 was specifically remarkable with nafamostat mesylate; the IC 50 decreased by approximately 6000 folds when the drug was used in the SARS-CoV-2-infected Calu-3 cells perhaps due to the dominant role of TMPRSS2-dependent viral entry in the Calu-3 human lung epithelial cells. In summary, we compared antiviral efficacy of the potential antiviral drug candidates against SARS-CoV-2 in between Vero and Calu-3 cells and found that nafamostat mesylate is the most potent antiviral drug candidate in vitro. Comparative analysis of antiviral efficacy of FDA-approved drugs against SARS-CoV-2 in human lung cells
cord-316908-8ti75mru	2020	Given that the differences in gene sequences and pathogenicity between classical and mutant strains of PEDV may lead to diverse invasion mechanisms, this study focused on the cellular entry pathways and cellular transport of the PEDV GI and GII subtype strains in Vero cells and IPEC-J2 cells. To clarify the specific endocytic pathways, systematic research methods were used and showed that PEDV enters cells via the clathrinand caveolae-mediated endocytosis pathways, in which dynamin II, clathrin heavy chain, Eps15, cholesterol, and caveolin-1 were indispensably involved. Our results showed that two the subtypes of PEDV utilized clathrin-, caveolae-, and lipid raft-mediated endocytosis to enter the Vero and IPEC-J2 cells, but the utilization efficiency of each endocytic pathway varied depending on the different genotypes and types of cells. We demonstrated that PEDV GI subtype GDS09 and GII subtype GDS01 strains could enter Vero and IPEC-J2 cells via the clathrin-, caveolae-, and lipid raft-mediated endocytosis pathways.
cord-323839-a4oejky0	2020	These results indicated that S gene mutants are resistant to the 1 5 9 treatment with TMPRRSS2 inhibitors, but are sensitive to antivirals that target post entry In an effort to understand the selection mechanisms underlying the generation of these 1 6 4 mutant variants, we estimated the frequency of S gene mutants in virus population of 1 6 5 SARS-CoV-2 that had undergone serial passage in cultured cells. In contrast, nucleotide sequence 1 7 2 deletions around the S1/S2 cleavage site corresponding to del1 and del2 mutants were 1 7 3 observed in all three biological replicates of SARS-CoV-2 populations passaged in Vero 1 7 4 cells (Fig. 5a) . Moreover, we must be very objective when interpreting the results 2 3 0 from studies using Vero-passaged virus, especially those focused on S protein cleavage, Cells were infected with either WT or S mutants of SARS-CoV-2 at an MOI of 1.
cord-329494-cdn52epy	2009	The efficacy of this Z2-siRNA against JUNV was also demonstrated in virus-infected cells, by testing infectious virus plaque formation (92.8% JUNV yield reduction), viral RNA level or antigen expression, as well as in cells transfected with Z-specific reporter plasmids (91% reduction in expression of Z-EGFP fusion protein). (E) Expression of viral antigens in Vero cells transfected with Z2-siRNA or X-siRNA and infected with JUNV was detected by immunofluorescence assay using a rabbit anti-JUNV polyclonal serum. The efficacy of this agent against JUNV was also demonstrated in virus-infected cells by testing infectious virus plaque formation, viral RNA or antigen expression, as well as in cells transfected with Z-specific reporter plasmids. The present study represents the first report of virus inhibition mediated by RNA interference for a New World arenavirus, a group in the family including four agents of severe viral hemorrhagic fevers in South America (JUNV, Machupo, Sabiá and Guanarito viruses).
cord-330772-i7cfmw9x	2019	The in vitro toxicity and antiviral ability of the surfactin-like peptide in the BLFP crude extract against PEDV were evaluated using the Vero cells. To study the antiviral activity of BLFP crude extract against PEDV, the biosurfactants were added at different time points during the viral infection. No statically significant difference in the average daily gain was noted among all groups each week BLFP crude extract with PEDV-infected cells during the whole study. Similarly, extracellular viral RNA levels in PEDV-infected cells cultured with biosurfactants were significantly lower than those without BLFP crude extract 24 and 48 HPI (Fig. 8b) . b Extracellular viral RNA levels in the supernatants of PEDV-infected Vero cells treated with or without BLFP crude extract were determined by real-time reverse transcription (RT)-PCR. d Intracellular viral RNA levels in the supernatants of PEDV-infected Vero cells treated with or without BLFP crude extract were determined by real-time RT-PCR.
cord-331094-22366b81	2020	We also screened 136 safe-in-man broad-spectrum antivirals against the SARS-CoV-2 infection in Vero-E6 cells and identified nelfinavir, salinomycin, amodiaquine, obatoclax, emetine and homoharringtonine. After the initial screening, we identified apilimod, emetine, amodiaquine, obatoclax, homoharringtonine, salinomycin, arbidol, posaconazole and nelfinavir as compounds that rescued virus-infected cells from death (AUC from 285 to 585; Table S1 ). We next profiled transcriptional responses to nelfinavir, amodiaquine or both drugs in virus-or mock-infected Vero-E6 cells at 24 h. Anti-SARS-CoV-2 activity of safe-in man broad-spectrum antivirals in Vero-E6 cells. Here, we found that combinations of nelfinavir with salinomycin, amodiaquine, obatoclax, emetine or homoharringtonine were synergistic against SARS-CoV-2 in Vero-E6 cells. Thus, the amodiaquine and nelfinavir combination could result in better efficacy and decreased toxicity for the treatment of SARS-CoV-2 and perhaps other viral infections. Transcriptomic analysis of mock-and SARS-CoV-2-infected Vero-E6 cells treated with nelfinavir, amodiaquine or both drugs.
cord-331680-qlzhtxs0	2020	In accordance with the purpose of the study, the following tasks were set: -to select the nucleotide sequence of the virus that is supposed to be inhibited, -to carry out the synthesis of oligonucleotide, -to determine cytotoxicity and antiviral activity in an in vitro experiment on cell culture. The assessment of antiviral activity of the drug in addition to cytopathic action was also taken into account by reducing the infectious titer of the virus in the culture of Vero cells E6 according to PCR RNA SARS-CoV-2, determined by the threshold of the number of reaction cycles (cycle treshold, Ct) in various dilutions of the study drug. Determination of the antiviral efficacy of the antisense oligonucleotide according to the treatment scheme (administration of the drug 24 hours after infection) was taken into account by the decrease in the infectious titer of the virus in the culture of Vero E6 cells by the cytopathic effect.
cord-332276-gs80celr	2007	In two independent studies, it was demonstrated that the inhibition of apoptosis, either by caspase inhibitors or by overexpression of the Bcl-2 protein, did not affect SARS-CoV replication in Vero cells (Ren et al., 2005; Bordi et al., 2006) , suggesting that apoptosis does not play a role in facilitating viral release. The mechanisms for induction of apoptosis by these SARS-CoV proteins are unclear, although in some cases, it could be related to their abilities to interfere with cellular functions, such as blocking cell cycle progression, altering membrane permeability, activating signal transduction pathways, upregulating transcription factors and other regulatory genes (Table 1 ). (2007) The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) gene 7 products contribute to virus-induced apoptosis. Over-expression of 7a, a protein specifically encoded by the severe acute respiratory syndrome (SARS) -coronavirus, induces apoptosis via a caspase-dependent pathway
cord-333208-tibtngy8	2016	The interferon-induced transmembrane (IFITM) protein family is a group of antiviral restriction factors that impair flexibility and inhibit membrane fusion at the plasma or the endosomal membrane, restricting viral progression at entry. The role of IFITM2 in the inhibition of ASFV in Vero cells could be related to impaired endocytosis-mediated viral entry and alterations in the cholesterol efflux, suggesting that IFITM2 is acting at the late endosome, preventing the decapsidation stage of ASFV. Thus, our goal in the current work was to test whether the IFITM family of proteins affected early entry steps of ASFV infection in Vero cell cultures using the cell-adapted Ba71V isolate. Confocal microscopy experiments revealed that, IFITM1 was mainly distributed at the plasma membrane and to a lesser extent in perinuclear compartments, resembling endosomal structures (Fig 3C, lower left panel) , while endogenous IFITM1 was barely detected in Vero cells containing the empty vector (Fig 3C, upper left panel) .
cord-339012-4juhmjaj	2020	Instead, PEDV down-regulated the expression of a set of zinc finger proteins with putative antiviral activity and enhanced the expression of the transmembrane serine protease gene TMPRSS13 (alias MSPL) to support its own infection by virus-cell membrane fusion (Shi et al, 2017, Viruses, 9(5):114). Furthermore, by comprehensive datamining in biological and chemical databases and consulting related literature we identified sets of PEDV-response genes with potential to influence i) the metabolism of biogenic amines (e.g. histamine), ii) the formation of cilia and "synaptic clefts" between cells, iii) epithelial mucus production, iv) platelets activation, and v) physiological processes in the body regulated by androgenic hormones (like blood pressure, salt/water balance and energy homeostasis). The detected sets of differential expressed genes (DEGs) for PEDV and MRV were analyzed by gene set enrichment analysis (GSEA) using functional bioinformatic programs to retrieve biological processes (pathways and Gene Ontology terms [GO-term]) and associations with chemical compounds, including drugs.
cord-343132-qqhivgkq	2020	The results showed that the intracellular extracts of Ln. mesenteroides YPK30 possessed in vitro prophylactic, therapeutic, and direct-inhibitory effects against PEDV in the Vero cell model. As shown in Figure 3 , the metabolic activity of Vero cells pretreated with the intracellular extracts of Ln. mesenteroides, regardless of which strain, were similar to those pretreated with IFN-α2b (p > 0.05) but were significantly higher than the un-pretreated cells (p < 0.05), indicating that all the Ln. mesenteroides strains isolated from kefir grains possessed in vitro prophylactic effects against PEDV. durans, Lb. kefiri, Lc. lactis, and Ln. mesenteroides , were isolated from kefir grains, and the in vitro prophylactic effects of the intracellular extracts of these four species against PEDV infection in Vero cells were compared. Therefore, the in vitro prophylactic and therapeutic effects of the intracellular extracts of Ln. mesenteroides YPK30 against PEDV in Vero cells seem not be attributed to the direct interaction of bacterial components or metabolites with virus.
cord-343515-fad1yyqx	2020	For SARS-CoV-2 (dark gray bars), statistically significant negative correlation coefficients (CC) were obtained for both cell lines, indicating that viral replication is increasingly inhibited by IFN-a. Observations were similar when the input MOI was reduced to 0.001 (Fig. S1 ), except that titers of SARS-CoV-1 in Calu-3 cells were already very low in the absence of any IFN-a, resulting in a nonsignificant effect of additional IFN. Our data thus indicate that (i) if anything, ruxolitinib is an enhancer rather than an inhibitor of SARS-CoV-2 multiplication, and (ii) the boosting effect is most likely due to inhibition of the antiviral JAK/ STAT signaling pathway, because it is not present in the IFN induction-deficient Vero E6 cells. For the statistical testing of the dose-response effect of IFN (type I and III) against SARS-coronaviruses, the typical regression procedures were not applicable because of several values below the detection limit and some ties in the data.
cord-345689-5ns1onkw	2009	Taking into account all the uncertainties and anticipating the worst-case scenario, many laboratories and vaccine manufacturers started working on a vaccine approach against SARS infection, largely based on what was known from animal CoVs. In this chapter, we will discuss the necessity for international cooperation and the importance of discretionary funding for rapidly developing a prototype vaccine candidate. When the laboratory work on the SARS-CoV vaccine development started, no data were available on the inactivation characteristics of the virus. The results from the experiments performed to evaluate the viral loss of the SARS-CoV due to drying on glass surface were also surprising: 35 -42 days were necessary to inactivate the virus to the detection limit of the technique. Based on our experience to date, the inactivated, adjuvanted SARS-CoV prototype vaccine seems to be a good candidate for further evaluation in Phase 1 studies.
cord-349689-njb6619x	2010	The goal of the current study was to evaluate the doseand time-dependent effects of chloroquine on CHIKV replication, and to elucidate the mechanism of viral inhibition in Vero cells. Anti-viral activity was assessed by performing cell viability assays on cells that had been infected with CHIKV in the presence of various concentrations of ammonium chloride, ribavirin, or chloroquine. The mechanism of inhibition of CHIKV activity by chloroquine was assessed by comparing the effects of chloroquine to those of a known lysomotropic agent (ammonium chloride) that interferes with early stages of infection, and a standard anti-viral compound (ribavirin) that inhibits virus replication during late stages of infection. To determine the anti-CHIKV activity of chloroquine, we analyzed virus yield in Vero cells treated with drug as compared to untreated infected control cells. We demonstrated that chloroquine is an effective anti-viral agent against CHIKV infection in Vero cells in culture, thus, demonstrating the in vitro prophylactic and therapeutic potential of chloroquine in inhibiting CHIVK infection.
cord-351377-xorj8tnz	2018	Moreover, inoculation with iPEDVPT-P96 elicited comparable levels of anti-PEDV specific plasma IgG and fecal/salivary IgA, neutralizing antibody titers, and similar but less effective immunoprotection against the virulent PEDVPT-P5 challenge compared to the parental PEDVPT-P96. In the present study, an infectious cDNA clone of an attenuated G2b PEDV strain was successfully generated for the first time, and the in vitro and in vivo data indicate that iPEDVPT-P96 is further attenuated but remains immunogenic compared to its parental PEDVPT-P96 viral stock. While one piglet in the PEDVPT-P96 group showed intermittent loose diarrhea (score = 1) and viral shedding at 6 to 11 days post-inoculation (DPI) with the peak viral titer of 1.45 ± 3.24 log 10 RNA copies/mL at 8 DPI (Figure 4) , no evidence of PEDV-associated clinical signs and fecal viral shedding were demonstrated in both iPEDVPT-P96 and mock groups.
cord-351525-306syrrn	2019	title: Broad Cross-Species Infection of Cultured Cells by Bat HKU2-Related Swine Acute Diarrhea Syndrome Coronavirus and Identification of Its Replication in Murine Dendritic Cells In Vivo Highlight Its Potential for Diverse Interspecies Transmission We first demonstrated that SADS-CoV possesses a broad species tropism and is able to infect cell lines from diverse species, including bats, mice, rats, gerbils, hamsters, pigs, chickens, nonhuman primates, and humans. As a brief summary of the results, 21 of the 24 cell lines showed significant susceptibility to SADS-CoV infection, defined by efficient viral replication, antigen expression, and the appearance of cytopathic effect (CPE). As some cells did not display CPE after SADS-CoV infection, all cell lines were subsequently tested for viral M protein expression by immunofluorescence assay (IFA) Fig. 1) , revealing the same range as seen by CPE in the different cell lines (data not shown).
cord-352511-gkm7i62s	2009	title: Acquisition of Cell–Cell Fusion Activity by Amino Acid Substitutions in Spike Protein Determines the Infectivity of a Coronavirus in Cultured Cells Here we report that acquisition of the cell–cell fusion activity by amino acid mutations in the S protein determines the infectivity of IBV in cultured cells. This study demonstrates that acquisition of the cell–cell fusion activity in S protein determines the selection and/or adaptation of a coronavirus from chicken embryo to cultured cells of human and animal origins. In this study, we report that acquisition of the cell-cell fusion activity by point mutations in the spike (S) protein of avian coronavirus infectious bronchitis virus (IBV) plays a critical role in adaptation and/or selection of a variant that infects cultured cells. Sequence comparison of two S protein constructs, S(EP3) and S(CK), cloned from EP3 and CK-adapted IBV strains, respectively, showed amino acid substitutions at 31 positions (Fig. 1a) .
cord-355440-20yq6zj0	2006	In this study, we compared the effects of NO and peroxynitrite on hantavirus replication and free mature virions in vitro, and of inducible nitric oxide synthase (iNOS) in hantavirus‐infected suckling mice. In the present study, we investigated the effect of NO and peroxynitrite on hantavirus replication in Vero E6 cells and on free mature virions by using S-nitroso-Nacetylpenicillamine (SNAP; an NO-donor), 3-morpholinosydnonimine hydrochloride (SIN-1; a peroxynitrite donor), and by stimulating endogenous NO production by iNOS with cytokines. From cells treated with 50 lM SNAP, 85% less viable virus was obtained, whereas lower concentrations of SNAP had no detectable effect on the virus replication, as compared to NAP-treated or medium controls ( Fig. 2A , and data not shown). However, the finding that iNOS -/suckling mice had higher levels of replicating virus than controls is in line with the finding that cytokine-stimulated NO production inhibited hantavirus replication in Vero E6 cells.