RESUMO
RNA interference (RNAi) is the major antiviral mechanism in plants and invertebrates, but the absence of detectable viral (v)siRNAs in mammalian cells upon viral infection has questioned the functional relevance of this pathway in mammalian immunity. We designed a series of peptides specifically targeting enterovirus A71 (EV-A71)-encoded protein 3A, a viral suppressor of RNAi (VSR). These peptides abrogated the VSR function of EV-A71 in infected cells and resulted in the accumulation of vsiRNAs and reduced viral replication. These vsiRNAs were functional, as evidenced by RISC-loading and silencing of target RNAs. The effects of VSR-targeting peptides (VTPs) on infection with EV-A71 as well as another enterovirus, Coxsackievirus-A16, were ablated upon deletion of Dicer1 or AGO2, core components of the RNAi pathway. In vivo, VTP treatment protected mice against lethal EV-A71 challenge, with detectable vsiRNAs. Our findings provide evidence for the functional relevance of RNAi in mammalian immunity and present a therapeutic strategy for infectious disease.
Assuntos
Antivirais/farmacologia , Infecções por Enterovirus/virologia , RNA Viral/antagonistas & inibidores , Animais , Chlorocebus aethiops , Enterovirus Humano A , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/farmacologia , Interferência de RNA , RNA Interferente Pequeno/antagonistas & inibidores , Células Vero , Replicação Viral/efeitos dos fármacosRESUMO
Foot-and-mouth disease virus (FMDV) remains a challenge for cloven-hooved animals. The currently licensed FMDV vaccines induce neutralizing antibody (NAb)-mediated protection but show defects in the early protection. Dendritic cell (DC) vaccines have shown great potency in inducing rapid T-cell immunity in humans and mice. Whether DC vaccination could enhance early protection against FMDV has not been elaborately explored in domestic pigs. In this study, we employed DC vaccination as an experimental approach to study the roles of cellular immunity in the early protection against FMDV in pigs. Autologous DCs were differentiated from the periphery blood mononuclear cells of each pig, pulsed with inactivated FMDV (iFMDV-DC) and treated with LPS, and then injected into the original pigs. The cellular immune responses and protective efficacy elicited by the iFMDV-DC were examined by multicolor flow cytometry and tested by FMDV challenge. The results showed that autologous iFMDV-DC immunization induced predominantly FMDV-specific IFN-γ-producing CD4+ T cells and cytotoxic CD8+ T cells (CTLs), high NAb titers, compared to the inactivated FMDV vaccine, and accelerated the development of memory CD4 and CD8 T cells, which was concomitantly associated with early protection against FMDV virulent strain in pigs. Such early protection was associated with the rapid proliferation of secondary T-cell response after challenge and significantly contributed by secondary CD8 effector memory T cells. These results demonstrated that rapid induction of cellular immunity through DC immunization is important for improving early protection against FMDV. Enhancing cytotoxic CD8+ T cells may facilitate the development of more effective FMDV vaccines.IMPORTANCEAlthough the currently licensed FMDV vaccines provide NAb-mediated protection, they have defects in early immune protection, especially in pigs. In this study, we demonstrated that autologous swine DC immunization augmented the cellular immune response and induced an early protective response against FMDV in pigs. This approach induced predominantly FMDV-specific IFN-γ-producing CD4+ T cells and cytotoxic CD8+ T cells, high NAb titers, and rapid development of memory CD4 and CD8 T cells. Importantly, the early protection conferred by this DC immunization is more associated with secondary CD8+ T response rather than NAbs. Our findings highlighted the importance of enhancing cytotoxic CD8+ T cells in early protection to FMDV in addition to Th1 response and identifying a strategy or adjuvant comparable to the DC vaccine might be a future direction for improving the current FMDV vaccines.
Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Vacinas Virais , Animais , Humanos , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , Linfócitos T CD8-Positivos , Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Vírus da Febre Aftosa/fisiologia , Suínos , VacinaçãoRESUMO
Zinc finger protein 36 (ZFP36) is a key regulator of inflammatory and cytokine production. However, the interplay between swine zinc-finger protein 36 (sZFP36) and foot-and-mouth disease virus (FMDV) has not yet been reported. Here, we demonstrate that overexpression of sZFP36 restricted FMDV replication, while the knockdown of sZFP36 facilitated FMDV replication. To subvert the antagonism of sZFP36, FMDV decreased sZFP36 protein expression through its non-structural protein 3C protease (3Cpro). Our results also suggested that 3Cpro-mediated sZFP36 degradation was dependent on its protease activity. Further investigation revealed that both N-terminal and C-terminal-sZFP36 could be degraded by FMDV and FMDV 3Cpro. In addition, both N-terminal and C-terminal-sZFP36 decreased FMDV replication. Moreover, sZFP36 promotes the degradation of FMDV structural proteins VP3 and VP4 via the CCCH-type zinc finger and NES domains of sZFP36. Together, our results confirm that sZFP36 is a host restriction factor that negatively regulates FMDV replication.IMPORTANCEFoot-and-mouth disease (FMD) is an infectious disease of animals caused by the pathogen foot-and-mouth disease virus (FMDV). FMD is difficult to prevent and control because there is no cross-protection between its serotypes. Thus, we designed this study to investigate virus-host interactions. We first demonstrate that swine zinc-finger protein 36 (sZFP36) impaired FMDV structural proteins VP3 and VP4 to suppress viral replication. To subvert the antagonism of sZFP36, FMDV and FMDV 3Cpro downregulate sZFP36 expression to facilitate FMDV replication. Taken together, the present study reveals a previously unrecognized antiviral mechanism for ZFP36 and elucidates the role of FMDV in counteracting host antiviral activity.
RESUMO
Hand, foot, and mouth disease (HFMD) is caused by more than 20 pathogenic enteroviruses belonging to the Picornaviridae family and Enterovirus genus. Since the introduction of the enterovirus-71 (EV71) vaccine in 2016, the number of HFMD cases caused by EV71 has decreased. However, cases of infections caused by other enteroviruses, such as coxsackievirus A6 (CA6) and coxsackievirus A10, have been increasing accordingly. In this study, we used a clinical isolate of CA6 to establish an intragastric infection mouse model using 7-day-old mice to mimic the natural transmission route, by which we investigated the differential gene expression profiles associated with virus infection and pathogenicity. After intragastric infection, mice exhibited hind limb paralysis symptoms and weight loss, similar to those reported for EV71 infection in mice. The skeletal muscle was identified as the main site of virus replication, with a peak viral load reaching 2.31 × 107 copies/mg at 5 dpi and increased infiltration of inflammatory cells. RNA sequencing analysis identified differentially expressed genes (DEGs) after CA6 infection. DEGs in the blood, muscle, brain, spleen, and thymus were predominantly enriched in immune system responses, including pathways such as Toll-like receptor signaling and PI3K-Akt signaling. Our study has unveiled the genes involved in the host immune response during CA6 infection, thereby enhancing our comprehension of the pathological mechanism of HFMD.IMPORTANCEThis study holds great significance for the field of hand, foot, and mouth disease (HFMD). It not only delves into the disease's etiology, transmission pathways, and severe complications but also establishes a novel mouse model that mimics the natural coxsackievirus A6 infection process, providing a pivotal platform to delve deeper into virus replication and pathogenic mechanisms. Additionally, utilizing RNA-seq technology, it unveils the dynamic gene expression changes during infection, offering valuable leads for identifying novel therapeutic drug targets. This research has the potential to enhance our understanding of HFMD, offering fresh perspectives for disease prevention and treatment and positively impacting children's health worldwide.
Assuntos
Infecções por Enterovirus , Enterovirus , Doença de Mão, Pé e Boca , Animais , Criança , Humanos , Camundongos , Anticorpos Antivirais , Modelos Animais de Doenças , Enterovirus/patogenicidade , Enterovirus/fisiologia , Enterovirus Humano A , Infecções por Enterovirus/patologia , Infecções por Enterovirus/virologia , Expressão Gênica , Doença de Mão, Pé e Boca/genética , Fosfatidilinositol 3-Quinases , VirulênciaRESUMO
Propagation of viruses requires interaction with host factors in infected cells and repression of innate immune responses triggered by the host viral sensors. Cytosolic DNA sensing pathway of cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) is a major component of the antiviral response to DNA viruses, also known to play a relevant role in response to infection by RNA viruses, including foot-and-mouth disease virus (FMDV). Here, we provide supporting evidence of cGAS degradation in swine cells during FMDV infection and show that the two virally encoded proteases, Leader (Lpro) and 3Cpro, target cGAS for cleavage to dampen the cGAS/STING-dependent antiviral response. The specific target sequence sites on swine cGAS were identified as Q140/T141 for the FMDV 3Cpro and the KVKNNLKRQ motif at residues 322-330 for Lpro. Treatment of swine cells with inhibitors of the cGAS/STING pathway or depletion of cGAS promoted viral infection, while overexpression of a mutant cGAS defective for cGAMP synthesis, unlike wild type cGAS, failed to reduce FMDV replication. Our findings reveal a new mechanism of RNA viral antagonism of the cGAS-STING innate immune sensing pathway, based on the redundant degradation of cGAS through the concomitant proteolytic activities of two proteases encoded by an RNA virus, further proving the key role of cGAS in restricting FMDV infection.
Assuntos
Vírus da Febre Aftosa , Animais , Suínos , Vírus da Febre Aftosa/metabolismo , Peptídeo Hidrolases/metabolismo , Transdução de Sinais , Imunidade Inata , Endopeptidases/genética , Endopeptidases/metabolismo , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Antivirais/metabolismoRESUMO
SignificanceMathematical models of infectious disease transmission continue to play a vital role in understanding, mitigating, and preventing outbreaks. The vast majority of epidemic models in the literature are parametric, meaning that they contain inherent assumptions about how transmission occurs in a population. However, such assumptions can be lacking in appropriate biological or epidemiological justification and in consequence lead to erroneous scientific conclusions and misleading predictions. We propose a flexible Bayesian nonparametric framework that avoids the need to make strict model assumptions about the infection process and enables a far more data-driven modeling approach for inferring the mechanisms governing transmission. We use our methods to enhance our understanding of the transmission mechanisms of the 2001 UK foot and mouth disease outbreak.
Assuntos
Teorema de Bayes , Doenças Transmissíveis/epidemiologia , Modelos Teóricos , Animais , Doenças Transmissíveis/transmissão , Surtos de Doenças , Febre Aftosa/epidemiologia , Humanos , Estatísticas não Paramétricas , Reino Unido/epidemiologiaRESUMO
We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.
Assuntos
Infecções por Enterovirus , Enterovirus , Doença de Mão, Pé e Boca , Criança , Humanos , Enterovirus/genética , Vietnã/epidemiologia , Doença de Mão, Pé e Boca/epidemiologia , Infecções por Enterovirus/epidemiologia , Extremidade Inferior , Antígenos ViraisRESUMO
Foot-and-mouth disease (FMD) is an acute, highly contagious disease of cloven-hoofed animals caused by FMD virus (FMDV). Currently, the molecular pathogenesis of FMDV infection remains poorly understood. Here, we demonstrated that FMDV infection induced gasdermin E (GSDME)-mediated pyroptosis independent of caspase-3 activity. Further studies showed that FMDV 3Cpro cleaved porcine GSDME (pGSDME) at the Q271-G272 junction adjacent to the cleavage site (D268-A269) of porcine caspase-3 (pCASP3). The inhibition of enzyme activity of 3Cpro failed to cleave pGSDME and induce pyroptosis. Furthermore, overexpression of pCASP3 or 3Cpro-mediated cleavage fragment pGSDME-NT was sufficient to induce pyroptosis. Moreover, the knockdown of GSDME attenuated the pyroptosis caused by FMDV infection. Our study reveals a novel mechanism of pyroptosis induced by FMDV infection and might provide new insights into the pathogenesis of FMDV and the design of antiviral drugs. IMPORTANCE Although FMDV is an important virulent infectious disease virus, few reports have addressed its relationship with pyroptosis or pyroptosis factors, and most studies focus on the immune escape mechanism of FMDV. GSDME (DFNA5) was initially identified as being associated with deafness disorders. Accumulating evidence indicates that GSDME is a key executioner for pyroptosis. Here, we first demonstrate that pGSDME is a novel cleavage substrate of FMDV 3Cpro and can induce pyroptosis. Thus, this study reveals a previously unrecognized novel mechanism of pyroptosis induced by FMDV infection and might provide new insights into the design of anti-FMDV therapies and the mechanisms of pyroptosis induced by other picornavirus infections.
Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Animais , Suínos , Vírus da Febre Aftosa/metabolismo , Caspase 3/metabolismo , Cisteína Endopeptidases/metabolismo , Gasderminas , Piroptose , Proteínas Virais/metabolismoRESUMO
Foot-and-mouth disease virus (FMDV) is a picornavirus, which infects cloven-hoofed animals to cause foot-and-mouth disease (FMD). The positive-sense RNA genome contains a single open reading frame, which is translated as a polyprotein that is cleaved by viral proteases to produce the viral structural and nonstructural proteins. Initial processing occurs at three main junctions to generate four primary precursors; Lpro and P1, P2, and P3 (also termed 1ABCD, 2BC, and 3AB1,2,3CD). The 2BC and 3AB1,2,3CD precursors undergo subsequent proteolysis to generate the proteins required for viral replication, including the enzymes 2C, 3Cpro, and 3Dpol. These precursors can be processed through both cis and trans (i.e., intra- and intermolecular proteolysis) pathways, which are thought to be important for controlling virus replication. Our previous studies suggested that a single residue in the 3B3-3C junction has an important role in controlling 3AB1,2,3CD processing. Here, we use in vitro based assays to show that a single amino acid substitution at the 3B3-3C boundary increases the rate of proteolysis to generate a novel 2C-containing precursor. Complementation assays showed that while this amino acid substitution enhanced production of some nonenzymatic nonstructural proteins, those with enzymatic functions were inhibited. Interestingly, replication could only be supported by complementation with mutations in cis acting RNA elements, providing genetic evidence for a functional interaction between replication enzymes and RNA elements. IMPORTANCE Foot-and-mouth disease virus (FMDV) is responsible for foot-and-mouth disease (FMD), an important disease of farmed animals, which is endemic in many parts of the world and can results in major economic losses. Replication of the virus occurs within membrane-associated compartments in infected cells and requires highly coordinated processing events to produce an array of nonstructural proteins. These are initially produced as a polyprotein that undergoes proteolysis likely through both cis and trans alternative pathways (i.e., intra- and intermolecular proteolysis). The role of alternative processing pathways may help coordination of viral replication by providing temporal control of protein production and here we analyze the consequences of amino acid substitutions that change these pathways in FMDV. Our data suggest that correct processing is required to produce key enzymes for replication in an environment in which they can interact with essential viral RNA elements. These data further the understanding of RNA genome replication.
Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Animais , Vírus da Febre Aftosa/metabolismo , Poliproteínas/genética , Poliproteínas/metabolismo , Replicação Viral/genética , Proteínas não Estruturais Virais/metabolismo , RNA/metabolismoRESUMO
Nonpharmaceutical interventions (NPIs) for coronavirus disease 2019 (COVID-19) not only reduce the prevalence of this disease among children but also influence the transmission of other viruses. This retrospective study investigated the impact of NPIs on human enterovirus (HEV) infection in children diagnosed with hand, foot, and mouth disease (HFMD) or herpangina (HA) in Hangzhou, China. We collected and analyzed the laboratory results and clinical data of children diagnosed with HFMD or HA during the following periods: pre-COVID-19 (January 2019 to December 2019), the COVID-19 pandemic (January 2020 to December 2022), and post-COVID-19 (January to December 2023). A total of 41 742 specimens that met the inclusion criteria were obtained, of which 1998 (4.79%) tested positive for enterovirus. In comparison to those in the pre-COVID-19 period, which had 695 (5.63%) HEV-positive specimens, the numbers dramatically decreased to 69 (1.19%), 398 (5.12%), and 112 (1.58%) in 2020, 2021, and 2022, respectively, but significantly increased to 724 (8.27%) in 2023. Seasonal peaks of infections occurred in May, June, July, and August each year, with the total detection rate ranging from 2019 to 2023 being 9.41% in May, 22.47% in June, 28.23% in July, and 12.16% in August, respectively. The difference in the detection rates of HEV infection between males and females was statistically significant (p < 0.005), with 5.11% (1221/23 898) of males and 4.35% (777/17 844) of females testing positive, resulting in a male-to-female positive ratio of 1.57:1. Among the age groups, 11.25% (378/3360) of the children aged 3-5 years had the highest detection rate, which steadily decreased with increasing or decreasing age. The detection of HEV indicated that >95% of the viruses were other types than the previously commonly reported enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). In conclusion, NPIs for COVID-19 may be effective at reducing the transmission of HEV. However, with the relaxation of NPIs, the detection rate of HEVs increased slowly to a certain extent. Active awareness and surveillance of the epidemiological characteristics of HEV are essential for preventing, controlling, and managing the development of HFMD and HA, as well as contributing to the development of a multivalent HFMD vaccine.
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COVID-19 , Infecções por Enterovirus , Enterovirus , Humanos , Feminino , Masculino , Criança , Pandemias , Estudos Retrospectivos , COVID-19/epidemiologia , Infecções por Enterovirus/epidemiologia , Antígenos Virais , China/epidemiologiaRESUMO
Coxsackievirus A16 (CV-A16) is a significant etiologic agent of hand, foot, and mouth disease (HFMD) and herpangina (HA), with the capacity to progress to severe complications, including encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis, and other critical conditions. Beijing's epidemiological surveillance system, established in 2008, encompasses 29 hospitals and 16 district disease control centers. From 2019 to 2021, the circulation of CV-A16 was characterized by the co-circulation of B1a and B1b clades. Multiple cases of HFMD linked to clade B1c has not been reported in Beijing until 2022. This study enrolled 400 HFMD and 493 HA cases. Employing real-time RT-PCR, 368 enterovirus-positive cases were identified, with 180 selected for sequencing. CV-A16 was detected in 18.89% (34/180) of the cases, second only to CV-A6, identified in 63.33% (114/180). Full-length VP1 gene sequences were successfully amplified and sequenced in 22 cases, revealing the presence of clades B1a, B1b, and B1c in 14, 3, and 5 cases, respectively. A cluster of five B1c clade cases occurred between June 29 and July 17, 2022, within a 7-km diameter region in Shunyi District. Phylogenetic analysis of five complete VP1 gene sequences and two full-genome sequences revealed close clustering with the 2018 Indian strain (GenBank accession: MH780757.1) within the B1c India branch, with NCBI BLAST results showing over 98% similarity. Comparative sequence analysis identified three unique amino acid variations (P3S, V25A, and I235V). The 2022 Shunyi District HFMD cases represent the first instances of spatiotemporally correlated CV-A16 B1c clade infections in Beijing, underscoring the necessity for heightened surveillance of B1c clade CV-A16 in HFMD and HA in this region.
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Doença de Mão, Pé e Boca , Filogenia , Humanos , Pequim/epidemiologia , Doença de Mão, Pé e Boca/virologia , Doença de Mão, Pé e Boca/epidemiologia , Masculino , Feminino , Pré-Escolar , Lactente , Criança , Genótipo , Enterovirus/genética , Enterovirus/classificação , Enterovirus/isolamento & purificação , Proteínas do Capsídeo/genética , Adolescente , Monitoramento EpidemiológicoRESUMO
Coxsackievirus B1 (CVB1), an enterovirus with multiple clinical presentations, has been associated with potential long-term consequences, including hand, foot, and mouth disease (HFMD), in some patients. However, the related animal models, transmission dynamics, and long-term tissue tropism of CVB1 have not been systematically characterized. In this study, we established a model of CVB1 respiratory infection in rhesus macaques and evaluated the clinical symptoms, viral load, and immune levels during the acute phase (0-14 days) and long-term recovery phase (15-30 days). We also investigated the distribution, viral clearance, and pathology during the long-term recovery period using 35 postmortem rhesus macaque tissue samples collected at 30 days postinfection (d.p.i.). The results showed that the infected rhesus macaques were susceptible to CVB1 and exhibited HFMD symptoms, viral clearance, altered cytokine levels, and the presence of neutralizing antibodies. Autopsy revealed positive viral loads in the heart, spleen, pancreas, soft palate, and olfactory bulb tissues. HE staining demonstrated pathological damage to the liver, spleen, lung, soft palate, and tracheal epithelium. At 30 d.p.i., viral antigens were detected in visceral, immune, respiratory, and muscle tissues but not in intestinal or neural tissues. Brain tissue examination revealed viral meningitis-like changes, and CVB1 antigen expression was detected in occipital, pontine, cerebellar, and spinal cord tissues at 30 d.p.i. This study provides the first insights into CVB1 pathogenesis in a nonhuman primate model of HFMD and confirms that CVB1 exhibits tissue tropism following long-term infection.
Assuntos
Modelos Animais de Doenças , Enterovirus Humano B , Doença de Mão, Pé e Boca , Macaca mulatta , Carga Viral , Tropismo Viral , Animais , Doença de Mão, Pé e Boca/virologia , Doença de Mão, Pé e Boca/patologia , Enterovirus Humano B/fisiologia , Enterovirus Humano B/patogenicidade , Anticorpos Antivirais/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Animais Recém-Nascidos , Citocinas/metabolismoRESUMO
BACKGROUND: Enterovirus 71 (EV-A71) causes Hand, Foot and Mouth Disease (HFMD) in children and has been associated with neurological complications. The molecular mechanisms involved in EV-A71 pathogenesis have remained elusive. METHODS: A siRNA screen in EV-A71 infected-motor neurons was performed targeting 112 genes involved in intracellular membrane trafficking, followed by validation of the top four hits using deconvoluted siRNA. Downstream approaches including viral entry by-pass, intracellular viral genome quantification by qPCR, Western blot analyses, and Luciferase reporter assays allowed determine the stage of the infection cycle the top candidate, RAB11A was involved in. Proximity ligation assay, co-immunoprecipitation and multiplex confocal imaging were employed to study interactions between viral components and RAB11A. Dominant negative and constitutively active RAB11A constructs were used to determine the importance of the protein's GTPase activity during EV-A71 infection. Mass spectrometry and protein interaction analyses were employed for the identification of RAB11A's host interacting partners during infection. RESULTS: Small GTPase RAB11A was identified as a novel pro-viral host factor during EV-A71 infection. RAB11A and RAB11B isoforms were interchangeably exploited by strains from major EV-A71 genogroups and by Coxsackievirus A16, another major causative agent of HFMD. We showed that RAB11A was not involved in viral entry, IRES-mediated protein translation, viral genome replication, and virus exit. RAB11A co-localized with replication organelles where it interacted with structural and non-structural viral components. Over-expression of dominant negative (S25N; GDP-bound) and constitutively active (Q70L; GTP-bound) RAB11A mutants had no effect on EV-A71 infection outcome, ruling out RAB11A's involvement in intracellular trafficking of viral or host components. Instead, decreased ratio of intracellular mature viral particles to viral RNA copies and increased VP0:VP2 ratio in siRAB11-treated cells supported a role in provirion maturation hallmarked by VP0 cleavage into VP2 and VP4. Finally, chaperones, not trafficking and transporter proteins, were found to be RAB11A's top interacting partners during EV-A71 infection. Among which, CCT8 subunit from the chaperone complex TRiC/CCT was further validated and shown to interact with viral structural proteins specifically, representing yet another novel pro-viral host factor during EV-A71 infection. CONCLUSIONS: This study describes a novel, unconventional role for RAB11A during viral infection where it participates in the complex process of virus morphogenesis by recruiting essential chaperone proteins.
Assuntos
Enterovirus Humano A , Proteínas rab de Ligação ao GTP , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Enterovirus Humano A/genética , Enterovirus Humano A/fisiologia , Enterovirus Humano A/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Replicação ViralRESUMO
Hand, Foot and Mouth Disease (HFMD) is a highly contagious viral illness primarily affecting children globally. A significant epidemiological transition has been noted in mainland China, characterized by a substantial increase in HFMD cases caused by non-Enterovirus A71 (EV-A71) and non-Coxsackievirus A16 (CVA16) enteroviruses (EVs). Our study conducts a retrospective examination of 36,461 EV-positive specimens collected from Guangdong, China, from 2013 to 2021. Epidemiological trends suggest that, following 2013, Coxsackievirus A6 (CVA6) and Coxsackievirus A10 (CVA10) have emerged as the primary etiological agents for HFMD. In stark contrast, the incidence of EV-A71 has sharply declined, nearing extinction after 2018. Notably, cases of CVA10 infection were considerably younger, with a median age of 1.8 years, compared to 2.3 years for those with EV-A71 infections, possibly indicating accumulated EV-A71-specific herd immunity among young children. Through extensive genomic sequencing and analysis, we identified the N136D mutation in the 2 A protein, contributing to a predominant subcluster within genogroup C of CVA10 circulating in Guangdong since 2017. Additionally, a high frequency of recombination events was observed in genogroup F of CVA10, suggesting that the prevalence of this lineage might be underrecognized. The dynamic landscape of EV genotypes, along with their potential to cause outbreaks, underscores the need to broaden surveillance efforts to include a more diverse spectrum of EV genotypes. Moreover, given the shifting dominance of EV genotypes, it may be prudent to re-evaluate and optimize existing vaccination strategies, which are currently focused primarily target EV-A71.
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Genoma Viral , Genótipo , Doença de Mão, Pé e Boca , Filogenia , China/epidemiologia , Humanos , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Pré-Escolar , Lactente , Estudos Retrospectivos , Feminino , Masculino , Criança , Epidemiologia Molecular , Enterovirus/genética , Enterovirus/classificação , Enterovirus/isolamento & purificação , Enterovirus Humano A/genética , Enterovirus Humano A/isolamento & purificação , Genômica , Incidência , Adolescente , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologiaRESUMO
Enterovirus 71 (EV-71) has strong neurotropism, and it is the main pathogen causing severe hand, foot, and mouth disease (HFMD). In clinical observations, significant differences were observed in the severity and prognosis of HFMD among children who were also infected with EV-71. Genetic differences among individuals could be one of the important causes of differences in susceptibility to EV-71-induced HFMD. As P-selectin glycoprotein ligand-1 (PSGL-1) is an important receptor of EV-71, the correlation between single-nucleotide polymorphisms (SNPs) in PSGL-1 and the susceptibility to severe HFMD following EV-71 infection is worth studying. Given the role of PSGL-1 in immunity, the correlations between PSGL-1 SNPs and the immune status after EV-71 infection are also worth studying. Meanwhile, PSGL-1 variable number of tandem repeats (VNTR) represents a research hotspot in cardiovascular and cerebrovascular diseases, but PSGL-1 VNTR polymorphism has not been investigated in HFMD caused by EV-71 infection. In this study, specific gene fragments were amplified by polymerase chain reaction, and PSGL-1 VNTR sequences were genotyped using an automatic nucleic acid analyzer. The correlations of PSGL-1 VNTR polymorphism with the susceptibility to EV-71-associated severe HFMD and the post-infection immune status were analyzed. The PSGL-1 VNTR A allele was identified as a susceptible SNP for severe HFMD. The risk of severe HFMD was higher for AA + AB genotype carriers than for BB genotype carriers. The counts of peripheral blood lymphocyte subsets were lower in AA + AB genotype carries than in BB genotype carries. In conclusion, PSGL-1 VNTR polymorphism is associated with the susceptibility to EV-71-induced severe HFMD and the immune status after infection. PSGL-1 VNTR might play a certain role in the pathogenesis of severe cases.
Assuntos
Enterovirus Humano A , Predisposição Genética para Doença , Doença de Mão, Pé e Boca , Glicoproteínas de Membrana , Repetições Minissatélites , Humanos , Doença de Mão, Pé e Boca/genética , Doença de Mão, Pé e Boca/imunologia , Doença de Mão, Pé e Boca/virologia , Glicoproteínas de Membrana/genética , Enterovirus Humano A/imunologia , Enterovirus Humano A/genética , Masculino , Feminino , Lactente , Repetições Minissatélites/genética , Pré-Escolar , Polimorfismo de Nucleotídeo Único , Genótipo , CriançaRESUMO
Coxsackievirus-A10 (CV-A10), responsible for the hand, foot and mouth disease (HFMD) pandemic, could cause serious central nervous system (CNS) complications. The underlying molecular basis of CV-A10 and host interactions inducing neuropathogenesis is still unclear. The Hippo signaling pathway, historically known for a dominator of organ development and homeostasis, has recently been implicated as an immune regulator. However, its role in host defense against CV-A10 has not been investigated. Herein, it was found that CV-A10 proliferated in HMC3 cells and promoted the release of inflammatory cytokines. Moreover, pattern recognition receptors (PRRs)-mediated pathways, including TLR3-TRIF-TRAF3-TBK1-NF-κB axis, RIG-I/MDA5-MAVS-TRAF3-TBK1-NF-κB axis and TLR7-MyD88-IRAK1/IRAK4-TRAF6-TAK1-NF-κB axis, were examined to be elevated under CV-A10 infection. Meanwhile, it was further uncovered that Hippo signaling pathway was inhibited in HMC3 cells with CV-A10 infection. Previous studies have been reported that there exist complex relations between innate immune and Hippo signaling pathway. Then, plasmids of knockdown and overexpression of MST1/2 were transfected into HMC3 cells. Our results showed that MST1/2 suppressed the levels of inflammatory cytokines via interacting with TBK1 and IRAK1, and also enhanced virus production via restricting IRF3 and IFN-ß expressions. Overall, these data obviously pointed out that CV-A10 accelerated the formation of neuroinflammation by the effect of the Hippo pathway on the PRRs-mediated pathway, which delineates a negative immunoregulatory role for MST1/2 in CV-A10 infection and the potential for this pathway to be pharmacologically targeted to treat CV-A10.
Assuntos
Benzenoacetamidas , Infecções por Coxsackievirus , NF-kappa B , Piperidonas , Humanos , NF-kappa B/metabolismo , Fator 3 Associado a Receptor de TNF/metabolismo , Doenças Neuroinflamatórias , Imunidade Inata , Citocinas/metabolismoRESUMO
The adjuvant is essential for vaccines because it can enhance or directly induce a strong immune response associated with vaccine antigens. Ginsenoside Rh2 (Rh2) had immunomodulatory effects but was limited by poor solubility and hemolysis. In this study, Rh2 liposomes (Rh2-L) were prepared by ethanol injection methods. The Rh2-L effectively dispersed in a double emulsion adjuvant system to form a Water-in-Oil-in-Water (W/O/W) emulsion and had no hemolysis. The physicochemical properties of the adjuvants were tested, and the immune activity and auxiliary effects indicated by the Foot-and-Mouth disease (FMDV) antigen were evaluated. Compared with the mice vaccinated with the FMD vaccine prepared with the double emulsion adjuvant alone, those with the FMD vaccine prepared with the double emulsion adjuvant containing Rh2-L had significantly higher neutralizing antibody titer and splenocyte proliferation rates and showed higher cellular and humoral immune responses. The results demonstrated that Rh2-L could further enhance the immune effect of the double emulsion adjuvant against Foot-and-Mouth Disease.
Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Vacinas Virais , Camundongos , Animais , Febre Aftosa/prevenção & controle , Lipossomos , Emulsões , Anticorpos Antivirais , Adjuvantes Imunológicos/farmacologia , Adjuvantes Farmacêuticos , ÁguaRESUMO
Foot-and-mouth disease is a highly contagious disease affecting cloven-hoofed animals, resulting in considerable economic losses. Its causal agent is foot-and-mouth disease virus (FMDV), a picornavirus. Due to its error-prone replication and rapid evolution, the transmission and evolutionary dynamics of FMDV can be studied using genomic epidemiological approaches. To analyze FMDV evolution and identify possible transmission routes in an Argentinean region, field samples that tested positive for FMDV by PCR were obtained from 21 farms located in the Mar Chiquita district. Whole FMDV genome sequences were obtained by PCR amplification in seven fragments and sequencing using the Sanger technique. The genome sequences obtained from these samples were then analyzed using phylogenetic, phylogeographic, and evolutionary approaches. Three local transmission clusters were detected among the sampled viruses. The dataset was analyzed using Bayesian phylodynamic methods with appropriate coalescent and relaxed molecular clock models. The estimated mean viral evolutionary rate was 1.17 × 10- 2 substitutions/site/year. No significant differences in the rate of viral evolution were observed between farms with vaccinated animals and those with unvaccinated animals. The most recent common ancestor of the sampled sequences was dated to approximately one month before the first reported case in the outbreak. Virus transmission started in the south of the district and later dispersed to the west, and finally arrived in the east. Different transmission routes among the studied herds, such as non-replicating vectors and close contact contagion (i.e., aerosols), may be responsible for viral spread.
Assuntos
Vírus da Febre Aftosa , Picornaviridae , Animais , Vírus da Febre Aftosa/genética , Argentina/epidemiologia , Teorema de Bayes , FilogeniaRESUMO
BACKGROUND: There is evidence suggesting that Notch1 signaling pathway contributes to the development of hand, foot, and mouth disease (HFMD); however, the role of Notch1 gene polymorphisms in the severity of coxsackievirus A6 (CVA6)-related HFMD remains unclear. This study aimed to investigate the correlation between Notch1 gene polymorphisms and the severity of CVA6-related HFMD. METHODS: A total of 196 patients (Chinese Han population) diagnosed with CVA6-related HFMD through nucleic acid testing were included in this study. Among them, 97 patients were classified as severe cases, while 99 cases were categorized as mild. The mRNA levels of Notch1 in the peripheral blood leukocytes of HFMD patients were detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was utilized for genotyping of rs3124599, rs3124603, and rs3124591. RESULTS: The frequencies of rs3124599 alleles were G (39.0%) and A (61.0%), while the frequencies of rs3124599 genotypes were GG (12.2%), GA (53.6%), and AA (34.2%), respectively. In the recessive model, the frequency of rs3124599 AA genotypes significantly increased in severe patients, compared to mild patients (P < 0.05). Due to the low frequency of alleles for rs3124591 and rs3124603 in patients, as well as the absence of any difference in their distribution between the two groups (P > 0.05), no additional statistical analysis was performed. After adjusting for age and sex, patients with rs3124599 AA genotype had a significantly higher risk of severe HFMD in comparison to G allele carriers (GA/GG), with an odds ratio (95% confidence interval) of 2.010 (1.094, 3.691). Meanwhile, the mRNA levels of Notch1 were found to be significantly higher in severe patients compared to mild patients (P < 0.05), and a positive correlation was observed between Notch1 mRNA levels and the peripheral blood monocyte count (r = 0.42, P < 0.001). Additionally, there were significant differences observed in Notch1 mRNA levels and peripheral blood monocyte counts between patients with the AA genotype of rs3124599 and those with the GA genotype or G allele carriers (P < 0.05). CONCLUSION: In the Chinese Han population, there is a strong correlation between the Notch1 rs3124599 allele and the severity of CVA6-related HFMD. This correlation may be attributed to genetic polymorphism of rs3124599 regulating Notch1 transcription levels. These findings reveal the important role of Notch1 gene polymorphism in CVA6 infection, establishing a scientific foundation for the precise control of severe HFMD.
Assuntos
Alelos , Povo Asiático , Enterovirus Humano A , Predisposição Genética para Doença , Doença de Mão, Pé e Boca , Polimorfismo de Nucleotídeo Único , Receptor Notch1 , Humanos , Masculino , Feminino , Doença de Mão, Pé e Boca/genética , Doença de Mão, Pé e Boca/virologia , Receptor Notch1/genética , China/epidemiologia , Pré-Escolar , Lactente , Povo Asiático/genética , Enterovirus Humano A/genética , Índice de Gravidade de Doença , Frequência do Gene , Genótipo , Criança , População do Leste AsiáticoRESUMO
BACKGROUND: Since December 2019, COVID-19 has spread rapidly around the world, and studies have shown that measures to prevent COVID-19 can largely reduce the spread of other infectious diseases. This study explored the impact of the COVID-19 outbreak and interventions on the incidence of HFMD. METHODS: We gathered data on the prevalence of HFMD from the Children's Hospital Affiliated to Zhengzhou University. An autoregressive integrated moving average model was constructed using HFMD incidence data from 2014 to 2019, the number of cases predicted from 2020 to 2022 was predicted, and the predicted values were compared with the actual measurements. RESULTS: From January 2014 to October 2022, the Children's Hospital of Zhengzhou University admitted 103,995 children with HFMD. The average number of cases of HFMD from 2020 to 2022 was 4,946, a significant decrease from 14,859 cases from 2014 to 2019. We confirmed the best ARIMA (2,0,0) (1,1,0)12 model. From 2020 to 2022, the yearly number of cases decreased by 46.58%, 75.54%, and 66.16%, respectively, compared with the forecasted incidence. Trends in incidence across sexes and ages displayed patterns similar to those overall. CONCLUSIONS: The COVID-19 outbreak and interventions reduced the incidence of HFMD compared to that before the outbreak. Strengthening public health interventions remains a priority in the prevention of HFMD.