Effectiveness and Safety of an Inactivated Enterovirus 71 Vaccine in Children Aged 6-71 Months in a Phase IV Study.

BACKGROUND: Evaluation of a licensed inactivated enterovirus type 71 (EV71) vaccine is needed in a phase IV study with a large population to identify its effectiveness and safety for further application. METHODS: An open-label, controlled trial involving a large population of 155 995 children aged 6-71 months was performed; 40 724 were enrolled in the vaccine group and received 2 doses of inactivated EV71 vaccine at an interval of 1 month, and the remaining children were used as the control group. The EV71-infected cases with hand, foot, and mouth disease were monitored in the vaccine and control groups during a follow-up period of 14 months since the 28th day postinoculation through the local database of the Notifiable Infectious Diseases Network. The effectiveness of the vaccine was estimated by comparing the incidence density in the vaccine group versus that in the control group based upon EV71-infected patients identified via laboratory testing. In parallel, the active and passive surveillance for safety of the vaccine was conducted by home or telephone visits and by using the Adverse Event Following Immunization (AEFI) system, respectively. RESULTS: An overall level of 89.7% (95% confidence interval, 24.0-98.6%) vaccine effectiveness against EV71 infection and a 4.58% rate of reported adverse events were observed. Passive surveillance demonstrated a 0.31% rate of reported common minor reactions. CONCLUSIONS: The clinical protection and safety of the EV71 vaccine were demonstrated in the immunization of a large population. CLINICAL TRIALS REGISTRATION: NCT03001986.

Mechanism for the lethal effect of enterovirus A71 intracerebral injection in neonatal mice.

Enterovirus A71 (EV-A71) infection is primarily responsible for fatal hand, foot, and mouth disease (HFMD) cases. Infants and younger children are more likely to suffer central nervous system damage as a result of EV-A71 infection, but this virus mostly does not affect older children and adults. This study investigated the possible mechanism underlying the age-dependent lethal effect of EV-A71 infection by comparing neonatal and adult mouse models of EV-A71 infection. Although viral proliferation is absent in both neonatal and adult mice, we observed that EV-A71, as a stimulus for astrocytes, elevates the levels of cytokines and monoamine neurotransmitters in neonatal mice. Then, we selected IL-6 and adrenaline as targets in a pharmacological approach to further validate the roles of these factors in mediating the mortality of neonatal mice after EV-A71 infection. Intracerebral injection of IL-6 and adrenaline enhanced the severity of EV-A71 infection, while treatment with an anti-IL-6-neutralizing antibody or the adrenergic-antagonist phenoxybenzamine reversed the lethal effect of EV-A71 in neonatal mice. These results suggest that the central nervous system (CNS) damage in neonatal cases of EV-A71 infection might be caused by an activated fetal cerebral immune response to the virus, including the disruption of brainstem function through increased levels of cytokines and neurotransmitters, rather than the typical cytopathic effect (CPE) of viral infection.

An inactivated enterovirus 71 vaccine in healthy children.

BACKGROUND: Enterovirus 71 (EV71) is a major cause of hand, foot, and mouth disease in children and may be fatal. A vaccine against EV71 is needed. METHODS: We conducted a randomized, double-blind, placebo-controlled phase 3 trial involving healthy children 6 to 71 months of age in Guangxi Zhuang Autonomous Region, China. Two doses of an inactivated EV71 vaccine or placebo were administered intramuscularly, with a 4-week interval between doses, and children were monitored for up to 11 months. The primary end point was protection against hand, foot, and mouth disease caused by EV71. RESULTS: A total of 12,000 children were randomly assigned to receive vaccine or placebo. Serum neutralizing antibodies were assessed in 549 children who received the vaccine. The seroconversion rate was 100% 4 weeks after the two vaccinations, with a geometric mean titer of 170.6. Over the course of two epidemic seasons, the vaccine efficacy was 97.4% (95% confidence interval [CI], 92.9 to 99.0) according to the intention-to-treat analysis and 97.3% (95% CI, 92.6 to 99.0) according to the per-protocol analysis. Adverse events, such as fever (which occurred in 41.6% of the participants who received vaccine vs. 35.2% of those who received placebo), were significantly more common in the week after vaccination among children who received the vaccine than among those who received placebo. CONCLUSIONS: The inactivated EV71 vaccine elicited EV71-specific immune responses and protection against EV71-associated hand, foot, and mouth disease. (Funded by the National Basic Research Program and others; ClinicalTrials.gov number, NCT01569581.).

A comparative study of multiple clinical enterovirus 71 isolates and evaluation of cross protection of inactivated vaccine strain FY-23 K-B in vitro.

BACKGROUND: Enterovirus 71 (EV71) is one of the causative agents of hand, foot and mouth disease, which mostly affects infants and children and leads to severe neurological diseases. Vaccination offers the best option for disease control. We have screened the virus strain FY-23 K-B, which is used as an inactivated vaccine strain. An important issue in the development of vaccines is whether they provide cross protection against all other strains. METHODS: We collected and identified 19 clinical EV71 isolates from mainland China, which all belong to the C4 genotype. We established growth curves of the strains in Vero cells, performed genetic analysis, and evaluated the cross protection efficacy through neutralizing assays using antisera from a rabbit, monkey and adult human immunized with the FY-23 K-B vaccine strain. RESULTS: The antisera showed broad cross protection among the C4 subgroup strains and homotype strain. Neutralizing indexes (NIs) among the isolates and homotype strain of antisera varied between 56.2-1995.3 for rabbit, 17.8-42,169.7 for monkey and 31.6-17,782.8 for human, whereas NIs against Coxsackievirus A16 or other enteroviruses were below 10. CONCLUSIONS: These results suggested that FY-23 K-B used as an antigen could elicit broad spectrum neutralizing antibodies with cross protective efficacy among C4 genotype strains.

Preparation and characterization of amine-functionalized sugarcane bagasse for CO2 capture.

A low-cost solid amine adsorbent for CO2 capture was prepared by using sugarcane bagasse (SB), a dominant agro-industrial residue in the sugar and alcohol industry as raw materials. In this preparation process, acrylamide was grafted on SB, and the grafted fiber was then aminated with different type of amine reagents to introduce primary and secondary amine groups onto the surface of SB fibers. The graft and amination conditions were optimized. The prepared solid amine adsorbent showed remarkable CO2 adsorption capacity and the adsorption capacity of the solid amine adsorbent could reach 5.01 mmol CO2/g at room temperature. The comparison of adsorption capacities of amine fibers aminated with various amination agents demonstrated that fibers aminated with triethylenetetramine would obtain higher adsorption capacities and higher amine efficiency. These adsorbents also showed good regeneration performance, the regenerated adsorbent could maintain almost the same adsorption capacity for CO2 after 10 recycles.

Virus-like structures for combination antigen protein mRNA vaccination.

Improved vaccination requires better delivery of antigens and activation of the natural immune response. Here we report a lipid nanoparticle system with the capacity to carry antigens, including mRNA and proteins, which is formed into a virus-like structure by surface decoration with spike proteins, demonstrating application against SARS-CoV-2 variants. The strategy uses S1 protein from Omicron BA.1 on the surface to deliver mRNA of S1 protein from XBB.1. The virus-like particle enables specific augmentation of mRNAs expressed in human respiratory epithelial cells and macrophages via the interaction the surface S1 protein with ACE2 or DC-SIGN receptors. Activation of macrophages and dendritic cells is demonstrated by the same receptor binding. The combination of protein and mRNA increases the antibody response in BALB/c mice compared with mRNA and protein vaccines alone. Our exploration of the mechanism of this robust immunity suggests it might involve cross-presentation to diverse subsets of dendritic cells ranging from activated innate immune signals to adaptive immune signals.

Preclinical safety evaluation of a bivalent inactivated EV71-CA16 vaccine in mice immunized intradermally.

Hand, foot and mouth disease is a common acute viral infectious disease that poses a serious threat to the life and health of young children. With the development of an effective inactivated EV71 vaccine, CA16 has become the main pathogen causing HFMD. Effective and safe vaccines against this disease are urgently needed. In our previous study, a bivalent inactivated vaccine was shown to have good immunogenicity and to induce neutralizing antibodies in mice and monkeys. Repeated administration toxicity is a critical safety test in the preclinical evaluation of vaccines. In this study, BALB/c mice were used to evaluate the toxicity of the bivalent vaccine after multiple intradermal administrations. Clinical observation was performed daily, and body weight, food intake, hematological characteristics, serum biochemical parameters, antinuclear antibodies, CD4+/CD8a+ T-cell proportions, bone marrow smear results and pathology results were recorded. The results showed that there was no significant change at the injection site and no adverse reactions related to the vaccine. The bivalent inactivated EV71-CA16 vaccine exhibits good safety in mice, and these results provide a sufficient basis for further clinical trials.

Pathogenic analysis of coxsackievirus A10 in rhesus macaques.

Coxsackievirus A10 (CV-A10) is one of the etiological agents associated with hand, foot and mouth disease (HFMD) and also causes a variety of illnesses in humans, including pneumonia, and myocarditis. Different people, particularly young children, may have different immunological responses to infection. Current CV-A10 infection animal models provide only a rudimentary understanding of the pathogenesis and effects of this virus. The characteristics of CV-A10 infection, replication, and shedding in humans remain unknown. In this study, rhesus macaques were infected by CV-A10 via respiratory or digestive route to mimic the HFMD in humans. The clinical symptoms, viral shedding, inflammatory response and pathologic changes were investigated in acute infection (1-11 day post infection) and recovery period (12-180 day post infection). All infected rhesus macaques during acute infection showed obvious viremia and clinical symptoms which were comparable to those observed in humans. Substantial inflammatory pathological damages were observed in multi-organs, including the lung, heart, liver, and kidney. During the acute period, all rhesus macaques displayed clinical signs, viral shedding, normalization of serum cytokines, and increased serum neutralizing antibodies, whereas inflammatory factors caused some animals to develop severe hyperglycemia during the recovery period. In addition, there were no significant differences between respiratory and digestive tract infected animals. Overall, all data presented suggest that the rhesus macaques provide the first non-human primate animal model for investigating CV-A10 pathophysiology and assessing the development of potential human therapies.

Pathogenesis study of enterovirus 71 infection in rhesus monkeys.

Enterovirus 71 (EV71), a major pathogen that is responsible for causing hand-foot-and-mouth disease (HFMD) worldwide, is a member of the Human Enterovirus species A, family Picornaviridae. HFMD that is caused by EV71 is usually characterized by vesicular lesions on the skin and oral mucosa and high morbidity rates in children; additionally, occasional fatal cases have been reported involving brainstem encephalitis and myelitis associated with cardiopulmonary collapse. Although viral pathogenesis in humans is unclear, previous animal studies have indicated that EV71, inoculated via various routes, is capable of targeting and injuring the central nervous system (CNS). We report here the pathogenic process of systemic EV71 infection in rhesus monkeys after inoculation via intracerebral, intravenous, respiratory and digestive routes. Infection with EV71 via these routes resulted in different rates of targeting to and injury of the CNS. Intracerebral inoculation resulted in pulmonary edema and hemorrhage, along with impairment of neurons. However, intravenous and respiratory inoculations resulted in a direct infection of the CNS, accompanied by obvious inflammation of lung tissue, as shown by impairment of the alveoli structure and massive cellular infiltration around the terminal bronchioles and small vessels. These pathological changes were associated with a peak of viremia and dynamic viral distribution in organs over time in the infected monkeys. Our results suggest that the rhesus monkey model may be used to study not only the basic pathogenesis of EV71 viral infections, but also to examine clinical features, such as neurological lesions, in the CNS and pathological changes in associated organs.

Efficacy of an inactivated bivalent vaccine for enterovirus 71 and coxsackievirus A16 in mice immunized intradermally.

Human hand, foot, and mouth disease (HFMD), an important infectious disease in children, is caused mainly by enterovirus 71 (EV71) and coxsackievirus A16 (CA16). In this study, a bivalent inactivated EV71/CA16 vaccine is developed and evaluated in immunized BALB/c mice injected through the intradermal route. Q-RT-PCR detection of the mRNA of immune signal molecules in local epithelial tissues inoculated with the vaccine indicates activation of innate immunity, which includes upregulation of immune-related chemokines, interferons and CD molecules. Further, the finding that neutralizing antibodies and specific T cellular responses were elicited in adult mice after two immunizations with the vaccine at a 28-day interval, which endowed offspring mice to defend a viral challenge, suggests the successful induction of specific protective antiviral immunity. All these data suggest that immunization with this bivalent EV71/CA16 vaccine via the intradermal route elicits effective immunity against EV71 and CA16 infection.

Preparation and characterization of a solid amine adsorbent for capturing CO2 by grafting allylamine onto PAN fiber.

Solid amine adsorbents using synthetic fibers instead of silica as the matrix are expected to offer more benefits for the adsorption of CO(2) because of high external surface area, low pressure drops, and flexibility of the matrix fibers. A novel kind of solid amine-containing fibrous adsorbent (PAN-AF) was prepared by preirradiation grafting copolymerization of allylamine onto polyacrylonitrile (PAN) fiber, using the redox system of (NH(4))(2)S(2)O(8)/NaHSO(3) as initiator. The effects of the reaction conditions such as reaction time, temperature, monomer concentration, amount of the initiator on grafting degree were studied. The results showed that the optimal conditions for the grafting copolymerization were using 50% allylamine monomer (V/V) and 1.5% (W/V) initiator and reacting at 100 degrees C for 10 h. FTIR was employed to characterize the corresponding changes on the surface chemical structure of PAN and PAN-AF. Thermal gravimetric analysis was used to evaluate the thermal stability of the materials. Equilibrium adsorption capacities for CO(2) and regeneration behaviors of PAN-AF were determined. Adsorption capacity for CO(2) of PAN-AF with 60.0 wt % grafting degree was 6.22 mmol CO(2)/g PAN-AF. PAN-AF could be completely regenerated by heating in boiling water for 30 min. The CO(2) adsorption performance of the regenerated PAN-AF was almost the same as that of the fresh adsorbent after several cycles, which revealed that PAN-AF exhibited good regenerating stability. The high speed and effective regeneration process proves that PAN-AF has great potential in industrial applications for CO(2) capture.

Significant elevation of B cells at the acute stage in enterovirus 71-infected children with central nervous system involvement.

A feature of the large outbreak of human enterovirus 71 (EV71)-associated hand-foot-and-mouth (HFMD) disease in China in 2008 was that severe cases presented with encephalitis. This study was performed to evaluate the immunophenotypic characteristics of patients with neurological involvement. Twenty-one patients with encephalitis and 14 with uncomplicated HFMD were recruited. Age-matched healthy volunteers were enrolled as controls. Peripheral lymphocyte subsets were analyzed by use of 3-colour flow cytometry, and the quantitative determination of plasma immunoglobulin (Ig) levels was also monitored. Comparisons between severe and mild cases demonstrated significant elevations of B cells and IgG levels and corresponding general decreases in natural killer (NK) cells and T lymphocytes in severe cases at the acute stage of infection (p < 0.01 for all). During the convalescent phase, rapid recoveries of B cells and IgG to the normal levels were observed, which appeared to be accompanied by an increase in EV71-specific neutralizing antibody titres. In summary, our data demonstrate that elevated B cells and IgG might be associated with neurological manifestations in EV71 infection.

Optimized development of a candidate strain of inactivated EV71 vaccine and analysis of its immunogenicity in rhesus monkeys.

Enterovirus type 71 (EV71) is one of the main etiologic agents responsible for periodic epidemics of hand-foot-and-mouth disease (HFMD). The prevention and control of EV71 epidemics with effective anti-viral agents and vaccines is very important for public health. Because the pathogenesis of EV71 in the human body is not completely clear and genetic variations in the virus during its replication are difficult to control, we have focused on the development of an inactivated whole-virus vaccine. In this study, we screened 16 strains isolated from different areas of China and selected one strain for the development of an inactivated EV71 vaccine. The results of our study suggest that the FY-23K-B strain, which is a candidate strain for an EV71 inactivated vaccine, satisfied the requirements of vaccine production in terms of genetic stability, biological activity, and good immunogenicity. The experimentally inactivated vaccine produced using this strain was capable of inducing an immune response and offered protection to rhesus monkeys against future virus attacks.

[Biological characters of a coxsackievirus B3 variant strain isolated from a hand-foot-mouth disease patient with severe clinical symptoms].

OBJECTIVE: To analyze the genetic and biological characters of a new isolate of coxsackievirus B3 (CoxB3), i.e. FY-19 strain, and investigate its mechanistic role in causing different clinical symptoms of hand-foot-mouth disease (HFMD). METHODS: FY-19 strain, isolated from a patient with severe clinical symptoms from Fuyang, China in 2008, was identified by the serological parameters via the Lim Benyesh-Melnick (LBM) antiserum pools. Its genotype was further characterized by sequencing the whole genome. And its biological characters were also examined by proliferation kinetic and pathogenetic analysis. RESULTS: FY-19 strain was identified as CoxB3 showing 23.0%, 16.5% and 32.1% difference with Nancy strain in 3'-, 5'-noncoding and coding regions respectively. FY-19 also showed a high homology with other HFMD-related CoxB3 isolates in China. But its homology with non-HFMD-related CoxB3 isolates was lower (13.5% and 25.0% difference in 3'-NCR and coding region respectively). The viral replication kinetic analysis suggested that the FY-19 proliferation increased rapidly and peaked at 14 hours post-infection. In pathological analysis, FY-19 strain induced mortal pathology in sucking mice. CONCLUSION: Differences in genetic and biological characters exist between FY-19 and Nancy strains. Further analysis on the pathogenesis of this variant may aid in elucidating the mechanisms of HFMD.

Study of integrated protective immunity induced in rhesus macaques by the intradermal administration of a bivalent EV71-CA16 inactivated vaccine.

Enterovirus type 71 (EV71) and coxsackievirus A 16 (CA16) are recognized as the major pathogens responsible for human hand-foot-mouth disease. To develop a bivalent EV71-CA16 vaccine, rhesus macaques immunized with two doses of this vaccine via the intradermal route were challenged with EV71 or CA16, and their clinical symptoms, viral shedding, neutralizing antibodies, IFN-γ-specific ELISpots, and tissue viral load were examined longitudinally. Specific immunity against EV71 and CA16 was observed in the macaques, which exhibited controlled proliferation of the EV71 and CA16 viruses and upregulated expression of immune-related genes compared with the controls. Furthermore, broad protection against EV71 and CA16 challenge without immunopathological effects was observed in all the immunized macaques. These studies suggest that the bivalent EV71-CA16 inactivated vaccine was effective against wild-type EV71 or CA16 viral challenge in rhesus macaques.

Immune responses of a CV-A16 live attenuated candidate strain and its protective effects in rhesus monkeys.

Coxsackievirus A16 (CV-A16) is a major causative pathogen of hand, foot, and mouth diseases (HFMDs). The licensed HFMD vaccine targets EV-A71 without cross-protection against CV-A16. Thus, a CV-A16 vaccine is needed. In this study, the immunogenicity and protective efficacy of a live attenuated CV-A16 candidate, K168-8Ac, were evaluated in a rhesus monkey model. Four passages of this strain (P35, P50, P60, and P70) were administered to monkeys, and its protective effect was identified. The immunized monkeys were clinically asymptomatic, except for slight fever. Weak viraemia was observed, and two doses of vaccination were found to significantly reduce virus shedding. High levels of antibody responses were observed (1:1024-1:2048), along with a significant increase in plasma IL-8. The I.M. group showed a much stronger humoural immunity. Pathological damage was detected mainly in lung tissues, although thalamus, spinal cord, lymph nodes, and livers were involved. After the viral challenge, it was found that two doses of vaccine reduced virus shedding, and the degree of lung damage and the number of organs involved decreased as the passage number increased. Overall, a robust immune response and partial protection against CV-A16, triggered by the K168-8Ac strain, were demonstrated. This study provides valuable data for CV-A16 vaccine development.

Role of innate lymphoid cells and dendritic cells in intradermal immunization of the enterovirus antigen.

Enterovirus type 71 (EV71) and coxsackievirus A 16 (CA16) are the major pathogens of human hand, foot, and mouth disease (HFMD). In our previous study, intramuscular immunization with the inactivated EV71 vaccine elicited effective immunity, while immunization with the inactivated CA16 vaccine did not. In this report, we focused on innate immune responses elicited by inactivated EV71 and CA16 antigens administered intradermally or intramuscularly. The distributions of the EV71 and CA16 antigens administered intradermally or intramuscularly were not obviously different, but the antigens were detected for a shorter period of time when administered intradermally. The expression levels of NF-κB pathway signaling molecules, which were identified as being capable of activating DCs, ILCs, and T cells, were higher in the intradermal group than in the intramuscular group. Antibodies for the EV71 and CA16 antigens colocalized with ILCs and DCs in skin and muscle tissues under fluorescence microscopy. Interestingly, ILC colocalization decreased over time, while DC colocalization increased over time. ELISpot analysis showed that coordination between DCs and ILCs contributed to successful adaptive immunity against vaccine antigens in the skin. EV71 and/or CA16 antigen immunization via the intradermal route was more capable of significantly increasing neutralizing antibody titers and activating specific T cell responses than immunization via the intramuscular route. Furthermore, neonatal mice born to mothers immunized with the EV71 and CA16 antigens were 100% protected against wild-type EV71 or CA16 viral challenge. Together, our results provide new insights into the development of vaccines for HFMD.

microRNA-4516 Contributes to Different Functions of Epithelial Permeability Barrier by Targeting Poliovirus Receptor Related Protein 1 in Enterovirus 71 and Coxsackievirus A16 Infections.

Enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) remain the predominant etiological agents of hand, foot, and mouth disease (HFMD). The clinical manifestations caused by the two viruses are obviously different. CV-A16 usually triggers a repeated infection, and airway epithelial integrity is often the potential causative factor of respiratory repeated infections. Our previous studies have demonstrated that there were some differentially expressed miRNAs involved in the regulation of adhesion function of epithelial barrier in EV-A71 and CV-A16 infections. In this study, we compared the differences between EV-A71 and CV-A16 infections on the airway epithelial barrier function in human bronchial epithelial (16HBE) cells and further screened the key miRNA which leaded to the formation of these differences. Our results showed that more rapid proliferation, more serious destruction of 16HBE cells permeability, more apoptosis and disruption of intercellular adhesion-associated molecules were found in CV-A16 infection as compared to EV-A71 infection. Furthermore, we also identified that microRNA-4516 (miR-4516), which presented down-regulation in EV-A71 infection and up-regulation in CV-A16 infection was an important regulator of intercellular junctions by targeting Poliovirus receptor related protein 1(PVRL1). The expressions of PVRL1, claudin4, ZO-1 and E-cadherin in CV-A16-infected cells were significantly less than those in EV-A71-infected cells, while the expressions of these proteins were subverted when pre-treated with miR-4516-overexpression plasmid in EV-A71 infected and miR-4516-knockdown plasmid in CV-A16 infected 16HBE cells. Thus, these data suggested that the opposite expression of miR-4516 in EV-A71 and CV-A16 infections might be the initial steps leading to different epithelial impairments of 16HBE cells by destroying intercellular adhesion, which finally resulted in different outcomes of EV-A71 and CV-A16 infections.

miR-1303 regulates BBB permeability and promotes CNS lesions following CA16 infections by directly targeting MMP9.

Coxsackievirus A16 (CA16) is a member of the Picornaviridae family and causes mild and self-limiting hand, foot, and mouth disease (HFMD) in infants and young children. CA16 infection can also progress to central nervous system (CNS) complications; however, the underlying mechanism by which CA16 penetrates the blood-brain barrier (BBB) and then causes CNS damage remains unclear. This study aimed to explore the mechanism of CA16 neurotropic tropism by establishing an in vitro BBB model with CA16 infection and an in vivo CA16 rhesus monkey infant infection model. The results showed that CA16 infection induced increased permeability of the BBB accompanied by upregulation of matrix metalloproteinase 9 (MMP9) expression. Subsequently, high-throughput miRNA sequencing technology and bioinformatics analysis revealed that miR-1303 may regulate BBB permeability by targeting MMP9. Next, we used dual-luciferase, qRT-PCR, and western blot assays to provide evidence of MMP9 targeting by miR-1303. Further experiments revealed that CA16 infection promoted the degradation of junctional complexes (Claudin4, Claudin5, VE-Cadherin, and ZO-1), likely by downregulating miR-1303 and upregulating MMP9. Finally, EGFP-CA16 infection could enter the CNS by facilitating the degradation of junctional complexes, eventually causing neuroinflammation and injury to the CNS, which was confirmed using the in vivo rhesus monkey model. Our results indicate that CA16 might penetrate the BBB and then enter the CNS by downregulating miR-1303, which disrupts junctional complexes by directly regulating MMP9 and ultimately causing pathological CNS changes. These results provide new therapeutic targets in HFMD patients following CA16 infection.

Comparison analysis of microRNAs in response to EV71 and CA16 infection in human bronchial epithelial cells by high-throughput sequencing to reveal differential infective mechanisms.

Hand, foot, and mouth disease (HFMD) mainly caused by Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) infections which presented significantly different clinical manifestations. Nevertheless, the factors underlying these differences remain unclear. Recently, the functions of microRNAs (miRNAs) in pathogen-host interactions have been highlighted. Here, we performed comprehensive miRNA profiling in EV71- and CA16-infected human bronchial epithelial (16HBE) cells at multiple time points using high-throughput sequencing. The results showed that 154 known and 47 novel miRNAs exhibited remarkable differences in expression. Of these, 65 miRNAs, including 58 known and 7 novel miRNAs, presented opposite trends in EV71- and CA16-infected samples. Subsequently, we mainly focused on the 56 known differentially expressed miRNAs by further screening for targets prediction. GO and pathway analysis of these targets demonstrated that 18 biological processes, 7 molecular functions, 1 cellular component and 123 pathways were enriched. Among these pathways, Cadherin signalling pathway, Wnt signalling pathway and angiogenesis showed significant alterations. The regulatory networks of these miRNAs with predicted targets, GOs, pathways and transcription factors were determined, which suggested that miRNAs displayed intricate regulatory mechanisms during the infection phase. Consequently, we specifically analysed the hierarchical GO categories of the predicted targets involved in adhesion. The results indicated that the distinct changes induced by EV71 and CA16 infection may be partly linked to airway epithelial barrier function. Taken together, our data provide useful insights that help elucidate the different host-pathogen interactions following EV71 and CA16 infection and might offer novel therapeutic targets for these infections.