Search

• This inactivated CVA2 vaccine could prevent the occurrence of severity and even death. • The inactivated CVA2 vaccine could induce high levels of neutralizing antibodies. • The inactivated CVA2 vaccine could induce cross-protection against EVA71 infection. Coxsackievirus A2 (CVA2) is one of the causative agents of hand-foot-and-mouth disease (HFMD), which poses a great challenge for global public health. However, presently, there are no available commercial vaccines or antivirals to prevent CVA2 infection. Here, we present an inactivated Vero cell-based whole CVA2 vaccine candidate and evaluate its safety and efficacy in this study. Neonatal BALB/c mice were vaccinated at 5 and 7 days old, respectively, and then challenged with either homologous or heterologous strain of CVA2 at a lethal dose at 10 days old. The inactivated whole CVA2 vaccine candidate showed a high protective efficacy. Additionally, our inactivated vaccine stimulated the production of CVA2-specific IgG1 and IgG2a antibodies in vivo and high titers of neutralization antibodies (NtAbs) in the serum of immunized mice. Maternal immunization with the inactivated CVA2 vaccine provided full protection to pups against lethal infection. Compared with mice inoculated with only alum, the viral loads were decreased, and pathological changes were relieved in tissue samples of immunized mice. Moreover, the transcription levels of some genes related to cytokines (IFN-γ and TNF-α, MCP-1, IL-6, CXCL-10 etc.) were significantly reduced. The number of immune cells and levels of cytokines in peripheral blood of mice inoculated with only alum were higher than that of immunized mice. It is noteworthy that this vaccine showed a good cross-immunity efficacy against Enterovirus A71 (EVA71) challenge. In conclusion, our findings suggest that this experimental inactivated CVA2 vaccine is a promising component of polyvalent vaccines related to HFMD in the near future. [ABSTRACT FROM AUTHOR]

Coxsackievirus A2 (CVA2) is associated with multiple diseases in children. Currently, there is limited research on immunological detection methods for CVA2. Herein, the VP1 gene of CVA2 strain 201711, belonging to cluster 2 within genotype D, was analyzed. The structures of VP1 from CVA2 strains 201711, 7-1 and 12-1, enterovirus A71 (EV-A71) strain 201713, coxsackievirus A16 (CVA16) strain 201717, and coxsackievirus A6 (CVA6) strain JLS10 were compared. The Escherichia coli BL21(DE3)/pET vector system was employed to express the recombinant protein containing the entire VP1 of CVA2 strain 201711. Mice were immunized with the purified protein, and the sera were collected and used to specifically identify the VP1 in CVA2-infected RD cells by Western blot and immunofluorescence assay. There was no evident cross-reactivity of the sera with the VP1 of EV-A71, CVA16, and CVA6 strains mentioned above. Therefore, this study provided mouse-specific anti-CVA2 VP1 polyclonal antibodies for CVA2 detection. • We compare the VP1 of CVA2, EV-A71, CVA16, and CVA6. • We prepare mouse-specific polyclonal antibodies against CVA2 VP1. • The antibodies do not cross-react with EV-A71, CVA16, and CVA6. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Certain types of enteroviruses, including coxsackieviruses, cause encephalitis, and other neurological complications. However, these pathogens rarely cause fatal infections, especially in immunocompetent infants. In this study, we present a rare case of acute encephalopathy caused by coxsackievirus A2 (CV-A2), which progressed rapidly in a previously healthy female child. Case presentation In June 2013, a 26-month-old female child from Kanagawa, Japan, was found unresponsive during sleep. She was healthy until that morning. Her temperature was 37 °C at 08:00. She was feeling fine and went to the nursery that same morning. However, her condition worsened around noon. Therefore, she went home and slept at around 13:00. Surprisingly, after 2 h, her parents checked on her and found that she was lying on her back and was not breathing. Hence, she was immediately taken to a hospital by ambulance, but she was declared dead on arrival at the hospital. Subsequently, pathological autopsy and pathogenetic analysis, including multiple pathogen detection real-time PCR, were conducted to investigate the cause of death. The examination results revealed that she had an infectious respiratory disease and acute encephalopathy due to a CV-A2 infection. Conclusions Based on our findings, we concluded that a previously healthy girl who had no immediate history of underlying medical condition were susceptible to death by acute encephalopathy due to CV-A2 infections. We proposed this conclusion because the patient’s condition progressed rapidly in less than 2 h and eventually led to her death. This is the first report on an acute encephalitis-dependent death in a child due to CV-A2 infection.

ABSTRACT Coxsackievirus A2 (CVA2) is an emerging pathogen that results in hand-foot-and-mouth disease (HFMD) outbreaks. Systemic inflammatory response and central nervous system inflammation are the main pathological features of fatal HFMD. However, the immunopathogenesis of CVA2 infection is poorly understood. We first detected the transcriptional levels of 81 inflammation-related genes in neonatal mice with CVA2 infection. Remarkably, CVA2 induced higher expression of chemokine (C-X-C motif) ligand 10 (CXCL10) in multiple organs and tissues. CXCL10 acts through its cognate receptor chemokine (C-X-C motif) receptor 3 (CXCR3) and regulates immune responses. CXCL10/CXCR3 activation contributes to the pathogenesis of many inflammatory diseases. Next, we found CXCL10 and CXCR3 expression to be significantly elevated in the organs and tissues from CVA2-infected mice at 5 days postinfection (dpi) using immunohistochemistry (IHC). To further explore the role of CXCL10/CXCR3 in CVA2 pathogenesis, an anti-CXCR3 neutralizing antibody (αCXCR3) or IgG isotype control antibody was used to treat CVA2-infected mice on the same day as infection and every 24 h until 5 dpi. Our results showed that αCXCR3 therapy relieved the clinical manifestations and pathological damage and improved the survival rate of CVA2-infected mice. Additionally, αCXCR3 treatment reduced viral loads and reversed the proinflammatory cytokine (interleukin 6 [IL-6], tumor necrosis factor alpha [TNF-α], and IL-1β) expression, apoptosis, and inflammatory cell infiltration induced by CVA2. Collectively, our study presents evidence for the involvement of the CXCL10/CXCR3 axis in CVA2 pathogenesis. The activation of CXCL10/CXCR3 contributes to CVA2 pathogenesis by inducing apoptosis, proinflammatory cytokine expression, and inflammatory cell infiltration, which can be reversed by αCXCR3 therapy. This study provides new insight into the pathogenesis of HFMD, which has an important guiding significance for the treatment of HFMD. IMPORTANCE Systemic inflammatory response and central nervous system inflammation are the main pathological features of fatal HFMD cases. We detected the expression of 81 inflammation-related genes and found higher expression of CXCL10 in CVA2-infected mice. Next, we confirmed CXCL10/CXCR3 activation using immunohistochemistry and found that anti-CXCR3 neutralizing antibody (αCXCR3) therapy could relieve the clinical manifestations and pathological damage and improve the survival rate of CVA2-infected mice. Additionally, αCXCR3 treatment reduced viral loads and reversed the proinflammatory cytokine (IL-6, TNF-α, and IL-1β) expression, apoptosis, and inflammatory cell infiltration induced by CVA2. Collectively, our study presents the first evidence for the involvement of the CXCL10/CXCR3 axis in CVA2 pathogenesis. The activation of CXCL10/CXCR3 contributes to CVA2 pathogenesis via inducing apoptosis, proinflammatory cytokine expression, and inflammatory cell infiltration, which can be reversed by αCXCR3 therapy. This study provides new insight into the pathogenesis of HFMD, which has an important guiding significance for the treatment of HFMD.

Coxsackievirus A2 (CVA2) has recently been constantly detected, and is associated with viral myocarditis in children. Our previous study demonstrated that CVA2 led to heart damage in a neonatal murine model. However, the molecular mechanism of heart injury caused by CVA2 remains largely unknown. Emerging evidence suggests the significant functions of miRNAs in Coxsackievirus infection. To investigate potential miRNAs involved in heart injury caused by CVA2, our study, for the first time, conducted a RNA-seq in vivo employing infected mice hearts. In total, 87, 101 and 76 differentially expressed miRNAs were identified at 3 days post infection (dpi), 7 dpi and 7 dpi vs 3 dpi. Importantly, above 3 comparison strategies shared 34 differentially expressed miRNAs. These results were confirmed by quantitative PCR (qPCR). Next, we did GO, KEGG, and miRNA-mRNA integrated analysis of differential miRNAs. The dual-luciferase reporter assay confirmed the miRNA-mRNA pairs. To further confirm the above enriched pathways and processes, we did Western blotting and immunofluorescence staining. Our results suggest that inflammatory responses, T cell activation, apoptosis, autophagy, antiviral immunity, NK cell infiltration, and the disruption of tight junctions are involved in the pathogenesis of heart injury caused by CVA2. The dysregulated miRNAs and pathways recognized in the current study can improve the understanding of the intricate interactions between CVA2 and the heart injury, opening a novel avenue for the future study of CVA2 pathogenesis. [ABSTRACT FROM AUTHOR]

Coxsackievirus A2 (CVA2) has recently been constantly detected, and is associated with viral myocarditis in children. Our previous study demonstrated that CVA2 led to heart damage in a neonatal murine model. However, the molecular mechanism of heart injury caused by CVA2 remains largely unknown. Emerging evidence suggests the significant functions of miRNAs in Coxsackievirus infection. To investigate potential miRNAs involved in heart injury caused by CVA2, our study, for the first time, conducted a RNA-seq in vivo employing infected mice hearts. In total, 87, 101 and 76 differentially expressed miRNAs were identified at 3 days post infection (dpi), 7 dpi and 7 dpi vs 3 dpi. Importantly, above 3 comparison strategies shared 34 differentially expressed miRNAs. These results were confirmed by quantitative PCR (qPCR). Next, we did GO, KEGG, and miRNA-mRNA integrated analysis of differential miRNAs. The dual-luciferase reporter assay confirmed the miRNA-mRNA pairs. To further confirm the above enriched pathways and processes, we did Western blotting and immunofluorescence staining. Our results suggest that inflammatory responses, T cell activation, apoptosis, autophagy, antiviral immunity, NK cell infiltration, and the disruption of tight junctions are involved in the pathogenesis of heart injury caused by CVA2. The dysregulated miRNAs and pathways recognized in the current study can improve the understanding of the intricate interactions between CVA2 and the heart injury, opening a novel avenue for the future study of CVA2 pathogenesis.

Background: Certain types of enteroviruses, including coxsackieviruses, cause encephalitis, and other neurological complications. However, these pathogens rarely cause fatal infections, especially in immunocompetent infants. In this study, we present a rare case of acute encephalopathy caused by coxsackievirus A2 (CV-A2), which progressed rapidly in a previously healthy female child.Case Presentation: In June 2013, a 26-month-old female child from Kanagawa, Japan, was found unresponsive during sleep. She was healthy until that morning. Her temperature was 37 °C at 08:00. She was feeling fine and went to the nursery that same morning. However, her condition worsened around noon. Therefore, she went home and slept at around 13:00. Surprisingly, after 2 h, her parents checked on her and found that she was lying on her back and was not breathing. Hence, she was immediately taken to a hospital by ambulance, but she was declared dead on arrival at the hospital. Subsequently, pathological autopsy and pathogenetic analysis, including multiple pathogen detection real-time PCR, were conducted to investigate the cause of death. The examination results revealed that she had an infectious respiratory disease and acute encephalopathy due to a CV-A2 infection.Conclusions: Based on our findings, we concluded that a previously healthy girl who had no immediate history of underlying medical condition were susceptible to death by acute encephalopathy due to CV-A2 infections. We proposed this conclusion because the patient's condition progressed rapidly in less than 2 h and eventually led to her death. This is the first report on an acute encephalitis-dependent death in a child due to CV-A2 infection. [ABSTRACT FROM AUTHOR]

Coxsackievirus (CV) A2 has emerged as an important etiological agent in the pathogen spectrum of hand, foot, and mouth disease (HFMD). The symptoms of CVA2 infections are generally mild, but worsen rapidly in some people, posing a serious threat to children’s health. However, compared with enterovirus 71 detected frequently in fatal cases, limited attention has been paid to CVA2 infections because of its benign clinical course. In the present study, we identified three CVA2 strains from HFMD infections and used the cell-adapted CVA2 strain HN202009 to inoculate 5-day-old BALB/c mice intramuscularly. These mice developed remarkably neurological symptoms such as ataxia, hind-limb paralysis, and death. Histopathological determination showed neuronophagia, pulmonary hemorrhage, myofiberlysis and viral myocarditis. Viral replication was detected in multiple organs and tissues, and CVA2 exhibited strong tropism to muscle tissue. The severity of illness was associated with abnormally high levels of inflammatory cytokines, including interleukin (IL)-6, IL-10, tumor necrosis factor α, and monocyte chemotactic protein 1, although the blockade of these proinflammatory cytokines had no obvious protection. We also tested whether an experimental formaldehyde-inactivated CVA2 vaccine could induce protective immune response in adult mice. The CVA2 antisera from the vaccinated mice were effective against CVA2 infection. Moreover, the inactivated CVA2 vaccine could successfully generate immune protection in neonatal mice. Our results indicated that the neonatal mouse model could be a useful tool to study CVA2 infection and to develop CVA2 vaccines.

Coxsackievirus (CV) A2 has emerged as an important etiological agent in the pathogen spectrum of hand, foot, and mouth disease (HFMD). The symptoms of CVA2 infections are generally mild, but worsen rapidly in some people, posing a serious threat to children's health. However, compared with enterovirus 71 detected frequently in fatal cases, limited attention has been paid to CVA2 infections because of its benign clinical course. In the present study, we identified three CVA2 strains from HFMD infections and used the cell-adapted CVA2 strain HN202009 to inoculate 5-day-old BALB/c mice intramuscularly. These mice developed remarkably neurological symptoms such as ataxia, hind-limb paralysis, and death. Histopathological determination showed neuronophagia, pulmonary hemorrhage, myofiberlysis and viral myocarditis. Viral replication was detected in multiple organs and tissues, and CVA2 exhibited strong tropism to muscle tissue. The severity of illness was associated with abnormally high levels of inflammatory cytokines, including interleukin (IL)-6, IL-10, tumor necrosis factor α, and monocyte chemotactic protein 1, although the blockade of these proinflammatory cytokines had no obvious protection. We also tested whether an experimental formaldehyde-inactivated CVA2 vaccine could induce protective immune response in adult mice. The CVA2 antisera from the vaccinated mice were effective against CVA2 infection. Moreover, the inactivated CVA2 vaccine could successfully generate immune protection in neonatal mice. Our results indicated that the neonatal mouse model could be a useful tool to study CVA2 infection and to develop CVA2 vaccines. [ABSTRACT FROM AUTHOR]

Coxsackievirus A2 (CVA2) has emerged as an active pathogen that has been implicated in hand, foot, and mouth disease (HFMD) and herpangina outbreaks worldwide. It has been reported that severe cases with CVA2 infection develop into heart injury, which may be one of the causes of death. However, the mechanisms of CVA2-induced heart injury have not been well understood. In this study, we used a neonatal mouse model of CVA2 to investigate the possible mechanisms of heart injury. We detected CVA2 replication and apoptosis in heart tissues from infected mice. The activity of total aspartate transaminase (AST) and lactate dehydrogenase (LDH) was notably increased in heart tissues from infected mice. CVA2 infection also led to the disruption of cell-matrix interactions in heart tissues, including the increases of matrix metalloproteinase (MMP)3, MMP8, MMP9, connective tissue growth factor (CTGF) and tissue inhibitors of metalloproteinases (TIMP)4. Infiltrating leukocytes (CD45+ and CD11b+ cells) were observed in heart tissues of infected mice. Correspondingly, the expression levels of inflammatory cytokines in tissue lysates of hearts, including tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), IL6 and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in CVA2 infected mice. Inflammatory signal pathways in heart tissues, including phosphatidylinositol 3-kinase (PI3K)-AKT, mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB), were also activated after infection. In summary, CVA2 infection leads to heart injury in a neonatal mouse model, which might be related to viral replication, increased expression levels of MMP-related enzymes and excessive inflammatory responses.

A natural recombinant of coxsackievirus A2 was found in 4 children with respiratory symptoms in Hong Kong, China, during the summer of 2012. Two of these children died. Vigilant monitoring of this emerging recombinant enterovirus is needed to prevent its transmission to other regions.

Background The monitoring and genotyping of Enterovirus (EV) infections can help to associate particular or severe clinical manifestations with specific EV types and to identify the aetiology of infectious outbreaks. Objectives To describe the epidemiological features of EV infections diagnosed during the year 2013 in the Greater Paris area (Ile de France). Study design During 2013, 2497 samples taken from 470 patients in 33 hospitals of Ile-de France were tested for EV genome by RT-PCR. EV genotyping was performed by the National Reference Centre (NRC) laboratories. EV infections were retrospectively reviewed by retrieving clinical and genotyping data from the NRC database. Results Of the 2497 samples, 490 (19.6%) was positive for EV genome detection. These EV infections represented 88.7% and 24.1%, respectively, of all reported regional and national infections. Twenty-seven different genotypes were identified. Echovirus 30 (E-30) accounted for 54.1% of all characterized strains and caused a large outbreak. Four severe neonatal infections were reported, of which two were caused by EV-A71. Respiratory infections involving EV-D68 were observed in two adults. One fatal case of Coxsackievirus A2-associated myocarditis was reported. Conclusion Monitoring EV infections in combination with EV genotyping via the French EV network characterized the epidemiology of EV infections in the Ile de France region in 2013 and documented severe EV infections associated with EV-A71 or CV-A2. [ABSTRACT FROM AUTHOR]

Enteroviruses can be introduced into the water environment as a result of human activity. Contaminations within hot tubs, spas and public baths are also possible. We investigated the distribution of enteroviruses at six hot spring recreation areas throughout Taiwan. Spring water was collected from 34 sites and enteroviruses were detected in 13 (38.2%). The most frequently detected was coxsackievirus A2, followed by echovirus 11. Enterovirus 71 (EV 71) and porcine enterovirus 9 were detected once. Water quality indicators were not statistically associated with the occurrence of enteroviruses, although the enterovirus-positive samples were positive for a greater number of microbiological indicators and showed a link to pH and water temperature. The results confirm the ubiquity of enteroviruses in Taiwan spring recreation areas. Coxsackievirus A2, echovirus 11 and EV 71, the enteroviruses responsible for disease outbreaks identified at these sites, should be considered a potential public health threat in spring recreation areas of Taiwan. [ABSTRACT FROM AUTHOR]

Sporadic occurrences and outbreaks of hand, foot, and mouth disease (HFMD) caused by Coxsackievirus A2 (CVA2) have frequently reported worldwide recently, which pose a great challenge to public health. Epidemiological studies have suggested that the main cause of death in critical patients is pulmonary edema. However, the pathogenesis of this underlying comorbidity remains unclear. In this study, we utilized the 5-day-old BALB/c mouse model of lethal CVA2 infection to evaluate lung damage. We found that the permeability of lung microvascular was significantly increased after CVA2 infection. We also observed the direct infection and apoptosis of lung endothelial cells as well as the destruction of tight junctions between endothelial cells. CVA2 infection led to the degradation of tight junction proteins (e.g., ZO-1, claudin-5, and occludin). The gene transcription levels of von Willebrand factor (vWF), endothelin (ET), thrombomodulin (THBD), granular membrane protein 140 (GMP140), and intercellular cell adhesion molecule-1 (ICAM-1) related to endothelial dysfunction were all significantly increased. Additionally, CVA2 infection induced the increased expression of inflammatory cytokines (IL-6, IL-1β, and MCP-1) and the activation of p38 mitogen-activated protein kinase (MAPK). In conclusion, the disruption of the endothelial barrier contributes to acute lung injury induced by CVA2 infection; targeting p38-MAPK signaling may provide a therapeutic approach for pulmonary edema in critical infections of HFMD. [ABSTRACT FROM AUTHOR]

Coxsackievirus A2 (CVA2) has emerged as an active pathogen that has been implicated in hand, foot, and mouth disease (HFMD) and herpangina outbreaks worldwide. It has been reported that severe cases with CVA2 infection develop into heart injury, which may be one of the causes of death. However, the mechanisms of CVA2-induced heart injury have not been well understood. In this study, we used a neonatal mouse model of CVA2 to investigate the possible mechanisms of heart injury. We detected CVA2 replication and apoptosis in heart tissues from infected mice. The activity of total aspartate transaminase (AST) and lactate dehydrogenase (LDH) was notably increased in heart tissues from infected mice. CVA2 infection also led to the disruption of cell-matrix interactions in heart tissues, including the increases of matrix metalloproteinase (MMP)3, MMP8, MMP9, connective tissue growth factor (CTGF) and tissue inhibitors of metalloproteinases (TIMP)4. Infiltrating leukocytes (CD45+ and CD11b+ cells) were observed in heart tissues of infected mice. Correspondingly, the expression levels of inflammatory cytokines in tissue lysates of hearts, including tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), IL6 and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in CVA2 infected mice. Inflammatory signal pathways in heart tissues, including phosphatidylinositol 3-kinase (PI3K)-AKT, mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB), were also activated after infection. In summary, CVA2 infection leads to heart injury in a neonatal mouse model, which might be related to viral replication, increased expression levels of MMP-related enzymes and excessive inflammatory responses. [ABSTRACT FROM AUTHOR]