Coxsackievirus B3 Research Articles

Synthesis, Antiviral and Cytostatic Activity of New Series of Naphthalimide Derivatives

A new series of N-(diethylphosphonoalkyl)-1,8-naphthalimides were synthesized via direct reaction of 1,8-naphthalic anhydride or its 3-nitro- and 4-bromo- derivatives with selected ɷ-aminoalkylphosphonates and evaluated against a broad-spectrum of viruses as well as for their cytostatic properties toward selected cell lines. N-(diethylphosphonomethyl)-3-nitro-1,8-naphthalimide 15a exhibited inhibitory activity toward coxsackie virus B4 in Vero cells (EC50 = 9.45 μM), whereas 3-nitro-1,8-naphthalimides 15b and 15d containing short 2-carbon linker showed moderate activity against herpes simplex virus-2 (G) and herpes simplex virus-1 TK– KOS ACVr. Furthermore, compounds 15a, 15b and 15d showed antiviral potency against human coronavirus. Several naphthalimides exhibited cytostatic activity toward tested cancerous cell lines as well as normal retina cells. Transformation of selected diethyl phosphonates 13, 14 and 15 into ammonium phosphonates 21, 22 and 23 improved the solubility, however, did not result in the enhancement of antiviral and cytostatic potency of the compounds.

Sex differences in left-ventricular strain in a murine model of coxsackievirus B3 myocarditis

Myocarditis is typically caused by viral infections, but most cases are thought to be subclinical. Echocardiography is often used for initial assessment of myocarditis patients but is poor at detecting subtle changes in cardiac dysfunction. Cardiac strain, such as global longitudinal strain (GLS) and global circumferential strain (GCS), represents an increasingly used set of measurements which can detect these subtle changes. Using a murine model of coxsackievirus B3 myocarditis, we characterized functional changes in the heart using echocardiography during myocarditis and by sex. We found that 2D GLS, 4D mode, and 4D strains detected a significant reduction in ejection fraction and GLS during myocarditis compared to baseline and in males compared to females. Furthermore, worse GLS correlated to increased levels of CD45+, CD11b+, and CD3+ immune cells. Our findings closely resemble published reports of GLS in patients with myocarditis indicating the usefulness of this animal model for translational studies of myocarditis.

Licochalcone A regulates viral IRES activity to inhibit enterovirus replication

Enterovirus D68 (EV-D68), belonging to the genus Enterovirus of the Picornavirus family, is an emerging pathogen that can cause neurological and respiratory diseases in children. However, there is little understanding of the pathogenesis of EV-D68, and no effective vaccine or drug for the prevention or treatment of the diseases caused by this virus is available. Autophagy is a cellular process that targets cytoplasmic proteins or organelles to the lysosomes for degradation. Enteroviruses strategically harness the host autophagy pathway to facilitate the completion of their life cycle. Therefore, we selected an autophagy compound library to screen for autophagy-related compounds that may affect viral growth. By using the neutralization screening assay, we identified a compound, ‘licochalcone A’ that significantly inhibited EV-D68 replication. To investigate the mechanism by which licochalcone A inhibits EV-D68 replication and to identify the viral life cycle stage it inhibits, the time-of-addition, viral attachment, viral entry, and dual-luciferase reporter assays were performed. The results of the time-of-addition assay showed that licochalcone A, a characteristic chalcone found in liquorice roots and widely used in traditional Chinese medicine, inhibits EV-D68 replication during the early stages of the viral life cycle, while those of the dual-luciferase reporter assay showed that licochalcone A does not regulate viral attachment and entry, but inhibits EV-D68 IRES-dependent translation. Licochalcone A also inhibited enterovirus A71 and coxsackievirus B3 but did not significantly inhibit dengue virus 2 or human coronavirus 229E replication. Licochalcone A regulates IRES translation to inhibit EV-D68 viral replication.

Modulation of myocardial inflammation, fibrosis development and ventricular arrhythmogenicity by endurance exercise in murine coxsackievirus B3 myocarditis

Abstract Aims Nonischaemic myocardial fibrosis is associated with progressive deterioration of myocardial function and forms the substrate for arrhythmias in atria and ventricles. In the absence of a specific aetiology, its origin is commonly attributed to preceding viral myocarditis. Athletes presenting with ventricular arrhythmias often demonstrate nonischaemic fibrosis on magnetic resonance imaging. Previous translational studies have shown an adverse effect of exercise on the course of acute viral myocarditis. Nevertheless, the effect on myocardial fibrosis development, a frequent and important consequence of viral myocarditis, has not yet been investigated. In the present study, we evaluate for the first time the impact of endurance exercise on longer-term myocardial inflammation, myocardial fibrosis and arrhythmogenicity using a murine viral myocarditis model. Methods and results Male C57BL/6J mice (11 weeks of age, n=72) were randomly assigned to 8 weeks of treadmill running (EEX) or without exercise (SED). Two weeks into the study (training or control), animals were injected intraperitoneally with either coxsackievirus B3 to induce acute viral myocarditis (CVB) or vehicle (PBS). Exercising myocarditis mice showed lower mortality (11% vs. 27%), albeit without statistical significance (P=0.23). At sacrifice (i.e. 6 weeks after inoculation), prominent myocardial inflammatory infiltration and cardiomyocyte loss was observed in both CVB groups, without difference on semiquantitative histological scoring. Nevertheless, the infiltrating cells in the CVB-EEX group were more often proinflammatory in nature (predominantly iNOS-reactive macrophages and positive CD8+/CD4+ ratio) compared to these in CVB-SED (predominantly arginase-1-reactive macrophages and higher CD4+/CD8+ ratio). In addition, the EEX group showed more haemosiderin-laden macrophages and spindled fibroblasts as signs of organisation. At that time, the majority of virus was cleared from the heart. Treadmill running during myocarditis enhanced development of interstitial fibrosis (with limited or extensive distribution)(82.4% in CVB-EEX vs. 56.3% in CVB-SED; P=0.049) and perivascular and/or interstitial fibrosis with extensive distribution (64.7% & 64.7% in CVB-EEX vs. 50% & 31.3% in CVB-SED; P=0.048). The highest scar counts were observed in CVB-EEX, but the mean count (1.9 vs. 1.2; P=0.19) did not significantly differ between the myocarditis groups. In CVB-EEX, the lesions contained denser and more organised collagen bundles. In vivo electrophysiology studies showed similar ventricular arrhythmia inducibility (P>0.20) and arrhythmia burden (P=0.49) in the myocarditis groups, although the longest arrhythmias and highest cumulative burden occurred in CVB-EEX. Conclusion Endurance exercise training during viral myocarditis modulates the longer-term inflammatory process and promotes perivascular and interstitial fibrosis development, potentially enhancing ventricular arrhythmogenicity.

Abstract 16000: β-arrestins Mediate Cardiac Infiltration of Cytotoxic CD8+ T Cells and Macrophages in Acute CVB3 Viral Myocarditis

Introduction: In response to Coxsackievirus B3 (CVB3) infection, immune cells infiltrate the heart affecting viral clearance, tissue damage, and cardiac remodeling. However, the molecular mechanisms regulating the immune response during acute CVB3-induced myocarditis are not well understood. β arrestins (βarrs), scaffolding proteins that mediate G protein-coupled receptor internalization, desensitization, and signaling are known to regulate immune responses. Hypothesis: We hypothesized that the immune populations infiltrating the heart during acute CVB3 infection are dependent on βarrs. Methods: To test our hypothesis, 5- to 7-week-old mice lacking βarr1 (βarr1 KO; n=8), βarr2 (βarr2 KO; n=4), or C57BL/6 controls (WT; n=7) were injected intraperitoneally with 1x10 4 plaque forming units (PFU) of CVB3 or saline and immune cell populations were measured in the heart at 7 days post infection (dpi) using flow cytometry. Results: At 7 dpi, there was a marked increase in cytotoxic CD8+ T cells in hearts of WT mice that positively correlated with the level of viral infection as assessed by heart tissue PFU (slope= 1.34, Y-intercept= -3.77). In contrast, the degree of infiltration of CD8+ T cells was significantly blunted in βarr KO hearts over a broad range of heart PFU (βarr1 KO: Slope=-0.3, Y-intercept=1.65; p=0.03 vs WT; βarr2 KO: Slope=-0.32, Y-intercept= 1.3; p=0.003 vs WT). Helper CD4+ T cell populations remained unaltered at 7 dpi among all groups. Macrophages at 7 dpi were significantly reduced in βarr KO hearts over a range of PFU (WT: Slope= 18.6, Y-intercept -52.32; βarr1 KO: Slope= -5, Y-intercept=32; βarr2 KO: Slope=3.46, Y-intercept=-8.4; p=0.04 vs WT). To assess cardiac injury, we measured the level of apoptosis by TUNEL staining and found that CVB3 infected βarr KO hearts showed significantly fewer TUNEL positive cells than WT CVB3 infected controls (WT 8.7%± 2.74; βarr1 KO 1.7%±0.51; βarr2 KO 1.7%±0.37; p=0.04 vs. WT). Conclusions: These data indicate that βarrs participate in the cardiac infiltration of CD8+ T cells and macrophages in response to CVB3 infection and that blocking the action of βarrs may diminish the cardiotoxicity with the acute phase of CVB3-induced myocarditis.

Abstract 13301: TRIM29 Causes Pathogenesis of Viral Myocarditis by Inducing PERK-Mediated Endoplasmic Reticulum Stress and Reactive Oxygen Species Responses

Introduction: Viral myocarditis is an inflammatory disease of the myocardium which contributes to a significant fraction of sudden death in children and young adults. The ongoing coronavirus disease 19 pandemic emphasizes the need for understanding the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Methods: To understand the role of the novel E3 ligase TRIM29 in controlling viral myocarditis, wild-type and TRIM29 knockout mice were infected with coxsackievirus B3 (CVB3) for inducing viral myocarditis. Mice survival and heart function were monitored by transthoracic echocardiography, and hearts were harvested for histology and immunohistochemistry analysis. Real-time PCR, western blotting, co-immunoprecipitation, enzyme-linked immunoassay, flow cytometry, over-expression and knockdown techniques were used to understand the pathogenic mechanisms of TRIM29 in regulating endoplasmic reticulum stress response after virus infection in this study. Results: We found that TRIM29 was highly induced by cardiotropic viruses, including CVB3 and encephalomyocarditis (EMCV), and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK) mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that restrict viral replication in cardiomyocytes in vitro . TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive cells in vivo . Mechanistically, TRIM29 interacted with PERK to catalyze SUMOylation of PERK for maintaining its stability, thereby promoting PERK-mediated signaling pathways. Conclusions: Our data provide the first evidence that TRIM29-mediated PERK signaling pathways cause pathogenesis of viral myocarditis and identify the TRIM29-PERK axis as a potential therapeutic target for treating viral induced cardiovascular diseases.

Molecular characterization of a novel clade echovirus 3 isolated from patients with hand-foot-and-mouth disease in southwest China.

Echovirus 3 (E3) belongs to the species Enterovirus B. Currently, three nearly whole-genome sequences of E3 are available in GenBank in China. In this study, we determined the whole genomic sequences of six E3 strains isolated from the stools of patients with hand-foot-and-mouth disease in Southwest China in 2022. Their nucleotide and amino acid sequences shared 82.1%-86.4% and 96.6%-97.2% identity with the prototype Morrisey strain, respectively, and showed 87.1% and 97.2% mutual identity. The six E3 strains are not clustered with other Chinese strains and formed a novel subgenotype (C6) with the recent American and British strains. Recombination analyses revealed that intertype recombination had occurred in the 2 C and 3D regions of the six E3 strains with coxsackieviruses B5 and B4, respectively. This study augments the nearly whole-genome sequences of E3 in the GenBank database and extends the molecular characterization of this virus in China.

Myocardial Mitochondrial DNA Drives Macrophage Inflammatory Response through STING Signaling in Coxsackievirus B3-Induced Viral Myocarditis.

Coxsackievirus B3 (CVB3), a single-stranded positive RNA virus, primarily infects cardiac myocytes and is a major causative pathogen for viral myocarditis (VMC), driving cardiac inflammation and organ dysfunction. However, whether and how myocardial damage is involved in CVB3-induced VMC remains unclear. Herein, we demonstrate that the CVB3 infection of cardiac myocytes results in the release of mitochondrial DNA (mtDNA), which functions as an important driver of cardiac macrophage inflammation through the stimulator of interferon genes (STING) dependent mechanism. More specifically, the CVB3 infection of cardiac myocytes promotes the accumulation of extracellular mtDNA. Such myocardial mtDNA is indispensable for CVB3-infected myocytes in that it induces a macrophage inflammatory response. Mechanistically, a CVB3 infection upregulates the expression of the classical DNA sensor STING, which is predominantly localized within cardiac macrophages in VMC murine models. Myocardial mtDNA efficiently triggers STING signaling in those macrophages, resulting in strong NF-kB activation when inducing the inflammatory response. Accordingly, STING-deficient mice are able to resist CVB3-induced cardiac inflammation, exhibiting minimal inflammation with regard to their functional cardiac capacities, and they exhibit higher survival rates. Moreover, our findings pinpoint myocardial mtDNA as a central element driving the cardiac inflammation of CVB3-induced VMC, and we consider the DNA sensor, STING, to be a promising therapeutic target for protecting against RNA viral infections.

SIRT-1 is required for release of enveloped enteroviruses

Enterovirus D68 (EV-D68) is a re-emerging enterovirus that causes acute respiratory illness in infants and has recently been linked to Acute Flaccid Myelitis. Here, we show that the histone deacetylase, SIRT-1, is essential for autophagy and EV-D68 infection. Knockdown of SIRT-1 inhibits autophagy and reduces EV-D68 extracellular titers. The proviral activity of SIRT-1 does not require its deacetylase activity or functional autophagy. SIRT-1’s proviral activity is, we demonstrate, mediated through the repression of endoplasmic reticulum stress (ER stress). Inducing ER stress through thapsigargin treatment or SERCA2A knockdown in SIRT-1 knockdown cells had no additional effect on EV-D68 extracellular titers. Knockdown of SIRT-1 also decreases poliovirus and SARS-CoV-2 titers but not coxsackievirus B3. In non-lytic conditions, EV-D68 is primarily released in an enveloped form, and SIRT-1 is required for this process. Our data show that SIRT-1, through its translocation to the cytosol, is critical to promote the release of enveloped EV-D68 viral particles.

SIRT-1 is required for release of enveloped enteroviruses.

Enterovirus D68 (EV-D68) is a re-emerging enterovirus that causes acute respiratory illness in infants and has recently been linked to Acute Flaccid Myelitis. Here, we show that the histone deacetylase, SIRT-1, is essential for autophagy and EV-D68 infection. Knockdown of SIRT-1 inhibits autophagy and reduces EV-D68 extracellular titers. The proviral activity of SIRT-1 does not require its deacetylase activity or functional autophagy. SIRT-1's proviral activity is, we demonstrate, mediated through the repression of endoplasmic reticulum stress (ER stress). Inducing ER stress through thapsigargin treatment or SERCA2A knockdown in SIRT-1 knockdown cells had no additional effect on EV-D68 extracellular titers. Knockdown of SIRT-1 also decreases poliovirus and SARS-CoV-2 titers but not coxsackievirus B3. In non-lytic conditions, EV-D68 is primarily released in an enveloped form, and SIRT-1 is required for this process. Our data show that SIRT-1, through its translocation to the cytosol, is critical to promote the release of enveloped EV-D68 viral particles.

Coxsackievirus A6 2C protein antagonizes IFN-β production through MDA5 and RIG-I depletion.

Coxsackievirus A6 (CV-A6) is a major emerging pathogen associated with atypical hand, foot, and mouth disease and can cause serious complications such as encephalitis, acute flaccid paralysis, and neurorespiratory syndrome. Therefore, revealing the associated pathogenic mechanisms could benefit the control of CV-A6 infections. In this study, we demonstrate that the nonstructural 2CCV-A6 suppresses IFN-β production, which supports CV-A6 infection. This is achieved by depleting RNA sensors such as melanoma differentiation-associated gene 5 and retinoic acid-inducible gene I (RIG-I) through the lysosomal pathway. Such a function is shared by 2CEV-A71 and 2CCV-B3 but not 2CCV-A16, suggesting the latter might have an alternative way to promote viral replication. This study broadens our understanding of enterovirus 2C protein regulation of the RIG-I-like receptor signaling pathway and reveals a novel mechanism by which CV-A6 and other enteroviruses evade the host innate immune response. These findings on 2C may provide new therapeutic targets for the development of effective inhibitors against CV-A6 and other enterovirus infections.

Umbilical Cord Mesenchymal-Stem-Cell-Derived Exosomes Exhibit Anti-Oxidant and Antiviral Effects as Cell-Free Therapies.

The oxidative stress induced by the accumulation of reactive oxygen species (ROS) can lead to cell aging and death. Equally, the skeletal muscle usually hosts enteroviral persistent infection in inflammatory muscle diseases. As excellent bioactive products, the exosomes derived from umbilical cord mesenchymal stem cells (ucMSCs) have been proven to be safe and have low immunogenicity with a potential cell-free therapeutic function. Here, exosomes derived from ucMSCs (ucMSC-EXO) were extracted and characterized. In a model of oxidative damage to skin fibroblasts (HSFs) under exposure to H2O2, ucMSC-EXO had an observable repairing effect for the HSFs suffering from oxidative damage. Furthermore, ucMSC-EXO inhibited mitogen-activated protein kinases (MAPK), c-Jun N-terminal kinase (JNK), and nuclear factor kappa-B (NF-κB) signaling pathways, thereby promoting p21 protein expression while decreasing lamin B1 protein expression, and finally alleviated oxidative stress-induced cell damage and aging. In a model of rhabdomyosarcoma (RD) cells being infected by enterovirus 71 (EV71) and coxsackievirus B3 (CVB3), the ucMSC-EXO enhanced the expression of interferon-stimulated gene 15 (ISG15) and ISG56 to inhibit enteroviral replication, whereafter reducing the virus-induced proinflammatory factor production. This study provides a promising therapeutic strategy for ucMSC-EXO in anti-oxidative stress and antiviral effects, which provides insight into extending the function of ucMSC-EXO in cell-free therapy.

Comprehensive profiling of neutralizing polyclonal sera targeting coxsackievirus B3

Despite their fundamental role in resolving viral infections, our understanding of how polyclonal neutralizing antibody responses target non-enveloped viruses remains limited. To define these responses, we obtained the full antigenic profile of multiple human and mouse polyclonal sera targeting the capsid of a prototypical picornavirus, coxsackievirus B3. Our results uncover significant variation in the breadth and strength of neutralization sites targeted by individual human polyclonal responses, which contrasted with homogenous responses observed in experimentally infected mice. We further use these comprehensive antigenic profiles to define key structural and evolutionary parameters that are predictive of escape, assess epitope dominance at the population level, and reveal a need for at least two mutations to achieve significant escape from multiple sera. Overall, our data provide a comprehensive analysis of how polyclonal sera target a non-enveloped viral capsid and help define both immune dominance and escape at the population level.

Effect and mechanism of 1, 25(OH)2D3 on myocardial inflammation induced by Coxsackie virus B3 in mice

Objective: To explore the effect and mechanism of 1, 25(OH)2D3 on myocardial inflammation induced by Coxsackie virus B3 (CVB3) in mice. Methods: Wild type (WT) and 1α-hydroxylase knockout [1(OH)ase-/-] male mice were divided into four groups: WT group, WT+CVB3 group, 1(OH)ase-/-+CVB3 group and 1(OH)ase-/-+CVB3+VD3 group, with 8 mice in each group. The indicators for evaluating myocardial cell injury were examined by different methods. The mRNA levels of pro-inflammatory cytokines [interlenkin (IL)-1β, IL-6, interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α)] were determined by quantitative real-time PCR. Hematoxylin-eosin (HE) staining was used to observe the myocardial histopathological changes. The apoptosis of myocardial cells was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. Fluo-4/AM fluorescence probe was used to detect intracellular calcium ion content. Meanwhile, the expression levels of Ca2+/Calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) protein as well as endoplasmic reticulum stress-related proteins like glucose-related protein 78 (GRP78) and C/EBP homologous protein (CHOP) in the myocardial tissues were detected by Western blot. Results: Compared with WT group, the mRNA levels of pro-inflammatory factors increased in the cardiomyocytes of mice in WT+CVB3 group, including IL-1β (14.88±3.32 vs 1.03±0.02, P=0.009), IL-6 (7.00±1.09 vs 1.81±0.18, P=0.005), IFN-γ (4.70±1.11 vs 1.34±0.34, P=0.006) and TNF-α (17.20±3.22 vs 1.02±0.12, P<0.001). Similarly, the infiltration of inflammatory cells, and the apoptosis rate of cardiomyocytes elevated (16.66%±1.09% vs 7.85%±1.12%, P=0.012). The level of calcium ions in myocardial cytoplasm was significantly higher in WT+CVB3 group than that in the WT group (2.98±1.05 vs 0.96±0.10, P=0.006). Likewise, the expression levels of pCaMKⅡ(1.97±0.34 vs 1.00±0, P<0.001), GRP78 (1.78±0.19 vs 1.00±0, P=0.005) and CHOP (1.62±0.09 vs 1.00±0, P=0.002) in WT+CVB3 group up-regulated. The above myocardial cell injury markers were more significant in the 1(OH)ase-/-+CVB3 group. In the 1(OH)ase-/-+CVB3+VD3 group, 1, 25(OH)2D3 supplementation significantly improved myocardial cell injury indicators. Meanwhile, the specific inhibitors of CaMKⅡ can also reduce the myocardial injury and apoptosis rate of CVB3-infected mice. Conclusion: 1, 25(OH)2D3 deficiency can aggravate myocardial inflammation through over activation of CaMKⅡ.

Cytoplasm Hydrogelation-Mediated Cardiomyocyte Sponge Alleviated Coxsackievirus B3 Infection.

Viral myocarditis (VMC), commonly caused by coxsackievirus B3 (CVB3) infection, lacks specific treatments and leads to serious heart conditions. Current treatments, such as IFNα and ribavirin, show limited effectiveness. Herein, rather than inhibiting virus replication, this study introduces a novel cardiomyocyte sponge, intracellular gelated cardiomyocytes (GCs), to trap and neutralize CVB3 via a receptor-ligand interaction, such as CAR and CD55. By maintaining cellular morphology, GCs serve as sponges for CVB3, inhibiting infection. In vitro results revealed that GCs could inhibit CVB3 infection on HeLa cells. In vivo, GCs exhibited a strong immune escape ability and effectively inhibited CVB3-induced viral myocarditis with a high safety profile. The most significant implication of this study is to develop a universal antivirus infection strategy via intracellular gelation of the host cell, which can be employed not only for treating defined pathogenic viruses but also for a rapid response to infection outbreaks caused by mutable and unknown viruses.

Non-small cell lung cancers (NSCLCs) oncolysis using coxsackievirus B5 and synergistic DNA-damage response inhibitors

With the continuous in-depth study of the interaction mechanism between viruses and hosts, the virus has become a promising tool in cancer treatment. In fact, many oncolytic viruses with selectivity and effectiveness have been used in cancer therapy. Human enterovirus is one of the most convenient sources to generate oncolytic viruses, however, the high seroprevalence of some enteroviruses limits its application which urges to exploit more oncolytic enteroviruses. In this study, coxsackievirus B5/Faulkner (CV-B5/F) was screened for its potential oncolytic effect against non-small cell lung cancers (NSCLCs) through inducing apoptosis and autophagy. For refractory NSCLCs, DNA-dependent protein kinase (DNA-PK) or ataxia telangiectasia mutated protein (ATM) inhibitors can synergize with CV-B5/F to promote refractory cell death. Here, we showed that viral infection triggered endoplasmic reticulum (ER) stress-related pro-apoptosis and autophagy signals, whereas repair for double-stranded DNA breaks (DSBs) contributed to cell survival which can be antagonized by inhibitor-induced cell death, manifesting exacerbated DSBs, apoptosis, and autophagy. Mechanistically, PERK pathway was activated by the combination of CV-B5/F and inhibitor, and the irreversible ER stress-induced exacerbated cell death. Furthermore, the degradation of activated STING by ERphagy promoted viral replication. Meanwhile, no treatment-related deaths due to CV-B5/F and/or inhibitors occurred. Conclusively, our study identifies an oncolytic CV-B5/F and the synergistic effects of inhibitors of DNA-PK or ATM, which is a potential therapy for NSCLCs.

Appendectomy Mitigates Coxsackievirus B3-Induced Viral Myocarditis.

Appendix has a distinct abundance of lymphatic cells and serves as a reservoir of microbiota which helps to replenish the large intestine with healthy flora. And it is the primary site of IgA induction, which shapes the composition of the intestinal microbiota. Recent population-based cohort studies report that appendectomy is associated with an increased risk of acute myocardial infarction and ischemic heart disease. Here, whether appendectomy has an effect on the occurrence and development of coxsackievirus B3 (CVB3)-induced viral myocarditis is studied. 103 TCID50 CVB3 was inoculated i.p. into appendectomized and sham-operated mice. RNA levels of viral load and pro-inflammatory cytokines in the hearts and the intestine were detected by RT-PCR. Compared to sham-operated mice, appendectomized mice exhibited attenuated cardiac inflammation and improved cardiac function, which is associated with a systemic reduced viral load. Appendectomized mice also displayed a reduction in cardiac neutrophil and macrophage infiltration and pro-inflammatory cytokine production. Mechanistically, we found that CVB3 induced an early and potent IL-10 production in the cecal patch at 2 days post infection. Appendectomy significantly decreased intestinal IL-10 and IL-10+ CD4+ Treg frequency which led to a marked increase in intestinal (primary entry site for CVB3) anti-viral IFN-γ+ CD4+ T and IFN-γ+ CD8+ T response and viral restriction, eventually resulting in improved myocarditis. Our results suggest that appendix modulates cardiac infection and inflammation through regulating intestinal IL-10+ Treg response.

Severe pneumonia and pathogenic damage in human airway epithelium caused by Coxsackievirus B4

ABSTRACT Coxsackievirus B4 (CVB4) has one of the highest proportions of fatal outcomes of other enterovirus serotypes. However, the pathogenesis of severe respiratory disease caused by CVB4 infection remains unclear. In this study, 3 of 42 (7.2%, GZ-R6, GZ-R7 and GZ-R8) patients with severe pneumonia tested positive for CVB4 infection in southern China. Three full-length genomes of pneumonia-derived CVB4 were sequenced and annotated for the first time, showing their high nucleotide similarity and clustering within genotype V. To analyze the pathogenic damage caused by CVB4 in the lungs, a well-differentiated human airway epithelium (HAE) was established and infected with the pneumonia-derived CVB4 isolate GZ-R6. The outcome was compared with that of a severe hand-foot-mouth disease (HFMD)-derived CVB4 strain GZ-HFM01. Compared with HFMD-derived CVB4, pneumonia-derived CVB4 caused more intense and rapid disruption of HAE polarity, leading to tight-junction barrier disruption, loss of cilia, and airway epithelial cell hypertrophy. More pneumonia-derived CVB4 were released from the basolateral side of the HAE than HFMD-derived CVB4. Of the 18 cytokines tested, only IL-6 and IL-1b secretion significantly increased on bilateral sides of HAE during the early stage of pneumonia-derived CVB4 infection, while multiple cytokine secretions significantly increased in HFMD-derived CVB4-infected HAE. HFMD-derived CVB4 exhibited stronger neurovirulence in the human neuroblastoma cells SH-SY5Y than pneumonia-derived CVB4, which is consistent with the clinical manifestations of patients infected with these two viruses. This study has increased the depth of our knowledge of severe pneumonia infection caused by CVB4 and will benefit its prevention and treatment.

Elucidation of benzene sulfonamide derivative binding at a novel interprotomer pocket of wild type and mutants of coxsackievirus B3 viral capsid using molecular dynamics simulations and density functional theory

Coxsackievirus B3 (CVB3), a serotype of enterovirus B, causes hand, foot, and mouth disease; pericarditis; and myocarditis. A benzene sulfonamide derivative is reported to have inhibitory activity against wild-type (WT) and eight mutants of the viral capsid of CVB3. Furthermore, the crystal structure of the complex formed between WT viral capsid of CVB3 and the derivative revealed binding at a novel druggable interprotomer pocket. We investigated how the compound could be a potent inhibitor of both WT and some mutants of CVB3 by determining binding to the viral capsid and the interaction energy with the binding pocket based on molecular dynamics simulations and density functional theory. We found that hydrogen bonds, pi–pi interactions, and electrostatic interactions are the key interactions with a protomer unit of CVB3 viral capsid. The residual interaction energy determined using density functional theory revealed key binding with VP1:Arg234 and a residue in the nearby VP1 unit (VP1’:Arg219). These results explain why the compound is still a potent inhibitor against eight mutants. Moreover, the decreased inhibitory activity for some mutants could be explained by the calculated binding energy and the highest occupied molecular orbital and lowest unoccupied molecular orbital energy. The results will be helpful for the development of drugs resistant to CVB3.

Hylin-a1: A Pan-Inhibitor against Emerging and Re-Emerging Respiratory Viruses.

Pandemic and epidemic outbreaks of respiratory viruses are a challenge for public health and social care system worldwide, leading to high mortality and morbidity among the human populations. In light of the limited efficacy of current vaccines and antiviral drugs against respiratory viral infections and the emergence and re-emergence of new viruses, novel broad-spectrum antiviral drugs are needed for the prevention and treatment of these infections. Antimicrobial peptides with an antiviral effect, also known as AVPs, have already been reported as potent inhibitors of viral infections by affecting different stages of the virus lifecycle. In the present study, we analyzed the activity of the AVP Hylin-a1, secreted by the frog Hypsiboas albopunctatus, against a wide range of respiratory viruses, including the coronaviruses HCoV-229E and SARS-CoV-2, measles virus, human parainfluenza virus type 3, and influenza virus H1N1. We report a significant inhibitory effect on infectivity in all the enveloped viruses, whereas there was a lack of activity against the naked coxsackievirus B3. Considering the enormous therapeutic potential of Hylin-a1, further experiments are required to elucidate its mechanism of action and to increase its stability by modifying the native sequence.