ObjectivesHuman metapneumovirus (hMPV) is a major cause of acute respiratory infections across all age groups, having developed a range of strategies to evade host immune responses. Currently, there is an absence of a comprehensive systematic review addressing these immune evasion mechanisms.MethodsWe conducted a systematic search of PubMed, Scopus, and Web of Science for articles published on hMPV immune evasion mechanisms up to March 1, 2025, including all English-language citations. The quality of the included articles was evaluated using the RTI Item Bank, CAMARADES, ARRIVE 2.0 guidelines, and a self-developed structured scale. We specifically analyzed the immune evasion mechanisms of hMPV during respiratory tract infections (RTIs).ResultsA total of 1322 articles were retrieved, of which 61 met the inclusion criteria. The findings reveal that hMPV has evolved a sophisticated, multilayered, and synergistic network for immune evasion. During the innate immune response, viral proteins (G, M2-2, SH, and P) suppress interferon (IFN) production by targeting pattern recognition receptors (e.g., RIG-I, TLR4) and their downstream adaptor molecules (e.g., MAVS, MyD88). Concurrently, the SH and G proteins disrupt the JAK-STAT signaling pathway, thereby impairing cellular responsiveness to IFN. During the adaptive immune phase, hMPV promotes T cell exhaustion through the activation of the PD-1/PD-L1 pathway and may evade antibody-mediated neutralization via structural extensions in the G protein, such as 180- and 111-nucleotide duplication. Furthermore, hMPV modulates host non-coding RNAs and epigenetic modifications, thereby orchestrating a comprehensive and multi-tiered disruption of immune defenses.ConclusionsThe immune evasion network of hMPV operates through coordinated actions of multiple viral proteins across innate and adaptive immunity. Key features include targeted blockade of IFN production and signaling, T-cell exhaustion, and emerging mechanisms involving RNA methylation and non-coding RNA regulation. These findings establish a conceptual framework for understanding hMPV persistence and provide potential targets for antiviral intervention. Understanding this network provides a theoretical foundation for developing targeted antiviral therapies and vaccines.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD420251018019.

Human metapneumovirus (hMPV) is a widespread and prevalent respiratory pathogen, yet the mechanisms by which hMPV modulates host gene expression to facilitate replication remain incompletely characterized. Here, we systematically profiled hMPV–host protein–protein interactions by affinity purification-mass spectrometry and assessed their impact on host mRNA splicing using RNA sequencing, complemented by genetic perturbation, protein interaction assays, and fluorescence microscopy–based subcellular localization and colocalization analyses. Among the viral proteins analyzed, the regulatory protein M2-2 was found to directly interact with multiple splicing factors. Transcriptomic analysis revealed that M2-2 triggers extensive changes in alternative splicing across host genes, notably affecting STRAP and TANC2, both of which exhibit distinctsplicing patterns during hMPV infection. Knockdown of M2-2 using short hairpin RNA (shRNA) during hMPV infection reversed M2-2–driven changes in the splicing patterns of STRAP and TANC2, confirming its regulatory role. Functional knockout of STRAP or TANC2 significantly impaired viral replication, indicating that the M2-2–favored isoforms are required for efficient viral propagation. Collectively, our findings demonstrate a novel mechanism by which hMPV M2-2 hijacks the host splicing machinery to reprogram key factors that facilitate viral replication. This extends the functional repertoire of M2-2 and highlights the virus–spliceosome interface as a potential therapeutic target for anti-hMPV intervention.

Alternative splicing (AS) significantly increases the diversity of the eukaryotic proteome, and alterations in AS induced by viruses have emerged as a novel approach to studying virus-host interactions. Human metapneumovirus (HMPV) interacts with host cells through multiple mechanisms, directly or indirectly utilising various host systems to facilitate infection and replication. In this study, the BEAS-2B human normal lung epithelial cell line was used as the cell model for HMPV infection. The host gene alternative splicing events following HMPV infection were then characterised using RNA sequencing. Selected alternative splicing events were confirmed and the associated genes evaluated for their effect on HMPV replication in knockout cell lines. HMPV replication was found to be greatly reduced in cells lacking the SEC11A gene, suggesting that the SEC11A gene is a critical host factor for HMPV infection. Notably, the SEC11A splicing pattern was not altered during infection with other respiratory viruses. In summary, this study reveals that SEC11A, which encodes the core catalytic subunit of the signal peptidase complex (SPC), is an essential host factor for HMPV infection. We observed a specific exon-skipping event in its mRNA precursor that occurs within the regulatory region upstream of the coding sequence. This atypical splicing site suggests that the virus may regulate SEC11A expression by interfering with the host splicing machinery. These findings provide new insights into HMPV pathogenesis and lay the groundwork for further exploration of HMPV-host interactions and the development of potential host-directed antiviral therapies.

Human metapneumovirus (HMPV) is a significant pathogen, causing widespread acute respiratory infections (ARIs). Rapid and accurate detection is crucial for timely diagnosis and outbreak control. To address the limitations of real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR)-based HMPV detection, we developed a novel method integrating recombinase-aided amplification (RAA) with CRISPR-Cas13a technology. Based on the alignment of 335 HMPV whole-genome sequences, a conserved region of the nucleocapsid (N) gene was selected for RAA primer and CRISPR RNA (crRNA) design. The concentrations of Cas protein, crRNA, and probe were optimized for specificity, sensitivity, and repeatability. A dual-mode platform was established, combining a fluorescence assay for quantitative detection and a lateral flow assay (LFA) for visual, on-site readout. Both methods were validated using 106 clinical samples and compared with RT-qPCR. Both methods demonstrated high specificity (no cross-reactivity with other respiratory viruses), a detection limit of 1 copy/μL, and excellent repeatability. Clinical validation showed complete concordance (κ = 1, p < 0.001) between the fluorescence assay and RT-qPCR, and high agreement for LFA (κ = 0.924, p < 0.001), with a sensitivity of 94.23%, specificity of 98.15%, positive predictive value (PPV) of 98%, and negative predictive value (NPV) of 94.6%. This study presents an RAA-CRISPR/Cas13a dual-mode platform for HMPV detection, providing a robust molecular diagnostic framework that paves the way for the future development of rapid testing assays.

Bacterial outer membrane vesicles (OMV) hold promise as vaccine platforms due to their natural adjuvant properties and nanoscale dimensions. However, their inherent inflammatory properties can induce excessive immune reactions, potentially harming the host, while their variability in size and low yield pose challenges for large-scale applications. To address these challenges, we developed synthetic bacterial vesicles (SyBV) through bacterial cell lysis followed by detergent treatment and sonication to eliminate nucleic acids, producing high-purity vesicles with minimal cytoplasmic residue. SyBV triggered comparable antigen-specific adaptive immunity but avoided strong inflammatory responses. We engineered SyBV to display the prefusion F protein (preF) of respiratory syncytial virus (RSV) with cytotoxic lysin A (ClyA). This approach effectively induced preF-specific antibodies and robust immune responses. Our findings suggest that SyBV could provide a safer, more efficient vaccine platform for preventing viral infections, overcoming the limitations associated with traditional OMV while preserving immunogenicity.

Previous studies have established that interferon (IFN) can inhibit the occurrence and progression of various tumors, particularly those associated with viral infections. However, the specific molecular mechanisms underlying its effects remain a key research focus. This study aims to elucidate how interferon inhibits Kaposi's sarcoma (KS), ultimately to improve its therapeutic efficacy against this condition. The role of IFN-α2b in treatingKS has been extensively studied, especially regarding its antiviral properties and immune regulatory functions. In this study, we demonstrate that IFN-α2b suppresses LANA expression in KSHV-infected cells, thereby reducing cell proliferation and increasing apoptosis. Further investigation into the molecular mechanisms revealed that IFN-α2b enhances the expression of GATA3, and that overexpression of GATA3 inhibits the phosphorylation of STAT5B. In summary, IFN-α2b exerts its inhibitory effects on KS by regulating GATA3 expression. Additionally, exploring the interactions between IFN-α2b and other molecules may uncover more complex tumor-suppressing mechanisms.

Washington University polyomavirus (WUPyV), a member of the polyomavirus family capable of infecting the human respiratory tract, exhibits high prevalence in human populations. However, confirmation of its pathogenicity and aetiology has been hindered by challenging culture conditions. To investigate the infective endocytosis of WUPyV, a novel infection model was developed using human airway organoids (HAOs); viral replication dynamics, cell tropism, endocytosis mechanisms, and morphogenesis in human airway epithelium (HAE) were characterized. The results indicated that WUPyV replicates efficiently and infects multiple cell types within the respiratory epithelium. After JC polyomavirus, WUPyV is the second human polyomavirus known to enter cells via clathrin-mediated endocytosis, independent of caveolar/lipid raft-mediated endocytosis or macropinocytosis. Consistent with other polyomaviruses, WUPyV is transported to the nucleus for replication and assembly through a lipid-dependent pathway requiring tyrosine kinase activity and endosome/lysosome acidification. Assembled viral particles were observed in nuclear pores; they were ultimately released extracellularly through vesicles and schistocytes. High-titre WUPyV infection caused extensive structural damage to the HAE and its cilia. Our findings provide important insights into the endocytosis, morphogenesis, and ultrastructural damage induced by WUPyV, supporting the notion that WUPyV is an underestimated human pathogen.

IntroductionRespiratory syncytial virus (RSV) remains a major international public health concern. However, disease treatment is limited to preventive care with monoclonal antibodies and supportive care. In this study, natural products were screened to identify novel anti-RSV inhibitors.MethodsThe antiviral effect of 320 compounds on RSV in HEp-2 cells was tested using a Cytopathic effect (CPE) inhibition assay. The antiviral effect of fumarprotocetraric acid (FUM) and geraniin (GE) were confirmed by Real-time reverse transcription quantitative PCR (Real-time RT-PCR), plaque reduction test, immunofluorescence assay, and Western blot analysis. Real-time PCR was used to detect inflammatory factor expression. ATP assay and JC-1 stain were used to evaluate mitochondrial protection function. The experiment of administration time was used to determine the stages in the RSV life cycle inhibited by FUM and GE. Human metapneumovirus (HMPV) and human rhinovirus (HRV) were used to evaluate the antiviral activities of other respiratory viruses of FUM and GE. Finally, Air-liquid interface human airway epithelium (ALI-HAE) cells were used to evaluate the antiviral effect and mechanism of FUM and GE to RSV.ResultsThe results showed that FUM and GE can inhibit the replication of RSV in multiple-cell models. Both compounds could dose-dependent inhibit the viral load, RSV nucleic acids level, and RSV-F protein level. Besides, FUM and GE showed good anti-inflammatory activity, mitochondrial protection, and antiviral activity to HMPV and HRV. Meanwhile, our result indicated that FUM and GE can inhibit RSV replication in ALI-HAE cells.ConclusionsFUM and GE were identified as new inhibitors of RSV infection. At the same time, FUM and GE have anti-inflammatory activity, mitochondrial protection function, and broad-spectrum antiviral activity. These results provide evidence that FUM and GE are potential candidates for the development of novel anti-RSV drugs.

To construct a high-titer Nipah pseudovirus packaging system using the HIV lentivirus backbone vector and establish a safe neutralization assay for Nipah pseudovirus in biosafety level 2 facilities. Nipah virus (NiV) fusion protein (F) and glycoprotein (G) recombinant expression plasmids, psPAX2, and pLenti CMV Puro LUC (w168-1) were transiently transfected into 293T cells for 72 h for the generation of a NiV pseudovirus. The neutralization ability of Nipah virus F and G protein antibodies was assessed using the pseudovirus. A NiV pseudovirus was constructed using 293T cells. The ideal mass ratio of plasmid psPAX2: w168-1: F: G for transfection was determined to be 4:4:1:1. The specificity of recombinant F and G protein expression was indicated by indirect immunofluorescence and western blotting. The pseudovirus particles showed obvious spikes under a transmission electron microscope. The NiV pseudovirus titer was 4.73 × 105 median tissue culture infective dose per mL, and the pseudovirus could be effectively neutralized by polyclonal antibodies specifically targeting the F and G proteins respectively. A NiV pseudovirus was successfully generated using HIV vector systems, and was used as a platform for a safe and reliable pseudovirus-based neutralizing assay that can be performed in biosafety level 2 facilities.

Background: Human metapneumovirus (HMPV) causes respiratory tract infections among infant, elderly, and immunocompromised patients, with significant mortality. Currently no licensed vaccines or therapeutic agents of HMPV exist.Methods: HMPV virus-like particle (VLP) was constructed by co-expressing fusion protein of HMPV and matrix 1 protein of influenza virus using the baculovirus expression. Mice were immunized with VLP with or without aluminum hydroxide (alum) adjuvant by intramuscular route respectively. Sera were determined for titers of IgG and neutralizing antibody. Splenic lymphocytes were determined by IFN-gamma and IL-4 ELISPOT. Mice were chal-lenged with HMPV, and protective efficacy was evaluated.Results: We generated HMPV VLP in baculovirus expression system. After three times immunization, IgG anti-body titers induced by VLP formulated with or without alum adjuvant group were 273,066 +/- 100,331 and 136,533 +/- 47,269 respectively, there was no difference (p > 0.05); the neutralizing antibody titers vaccinated with VLP plus with alum adjuvant (266 +/- 92) were higher than those of the VLP alone group (106 +/- 37). For IFN-gamma, mice vaccinated with VLP with or without alum adjuvant are 151 +/- 36.4 and 77.0 +/- 17.1SFC/106 respectively, there was difference (p = 0.03); For IL-4, they are 261.3 +/- 38.7 versus 125.67 +/- 29.78SFC/106 respectively, the difference was significant (p = 0.009). After challenge, in pathological analysis, the overall lesion scores in the VLP plus with and without alum adjuvant were 3.25 and 5.6 respectively, those of control group is 8. For immunohistochemical analyses, the average optical density of the lungs in the VLP immunized group containing adjuvant (9.07 +/- 1.74) was lower than that in the VLP group without adjuvant (12.83 +/- 2.31, p = 0.14).Conclusions: This is the first study to demonstrate that HMPV VLP was successfully prepared in the baculovirus expression system. HMPV VLP could induce specific humoral and cellular immune responses as well as protective efficacy, and aluminum hydroxide may be an effective adjuvant in mice.

Human metapneumovirus (HMPV) is a major pathogen of acute respiratory tract infections (ARTIs) in children. Whole genome sequence analyses could help understand the evolution and transmission events of this virus. In this study, we sequenced HMPV whole genomes to improve the identification of molecular epidemiology in Beijing, China. Nasopharyngeal aspirates of hospitalized children aged < 14 years old with ARTIs were screened for HMPV infection using qPCR. Fourteen pairs of overlapping primers were used to amplify whole genome sequences of HMPV from positive samples with high viral loads. The epidemiology of HMPV was analysed and 27 HMPV whole genome sequences were obtained. Sequence identity and the positional entropy analyses showed that most regions of HMPV genome are conserved, whereas the G gene contained many variations. Phylogenetic analysis identified 25 HMPV sequences that belonged to a newly defined subtype A2b1; G gene sequences from 24 of these contained a 111-nucleotide duplication. HMPV is an important respiratory pathogen in paediatric patients. The new subtype A2b1 with a 111-nucleotide duplication has become predominate in Beijing, China.

Background Although coronavirus disease 2019 (COVID-19) pandemic is still rage worldwide, there are still very limited treatments for human coronaviruses (HCoVs) infections. Xiaochahu decoction (XCHD), which is one of the traditional Chinese medicine (TCM) prescriptions in Qingfeipaidu decoction (QFPDD), is widely used for COVID-19 treatment in China and able to relieve the symptoms of fever, fatigue, anorexia, and sore throat. To explore the role and mechanisms of XCHD against HCoVs, we presented an integrated systems pharmacology framework in this study. Methods We constructed a global herb-compound-target (H-C-T) network of XCHD against HCoVs. Multi-level systems pharmacology analyses were conducted to highlight the key XCHD-regulated proteins, and reveal multiple HCoVs relevant biological functions affected by XCHD. We further utilized network-based prediction, drug-likeness analysis, combining with literature investigations to uncover the key ani-HCoV constituents in XCHD, whose effects on anit-HCoV-229E virus were validated using cytopathic effect (CPE) assay. Finally, we proposed potential molecular mechanisms of these compounds against HCoVs via subnetwork analysis. Results Based on the systems pharmacology framework, we identified 161 XCHD-derived compounds interacting with 37 HCoV-associated proteins. An integrated pathway analysis revealed that the mechanism of XCHD against HCoVs is related to TLR signaling pathway, RIG-I-like receptor signaling pathway, cytoplasmic DNA sensing pathway, and IL-6/STAT3 pro-inflammatory signaling pathway. Five compounds from XCHD, including betulinic acid, chrysin, isoliquiritigenin, schisandrin B, and (20R)-Ginsenoside Rh1 exerted inhibitory activity against HCoV-229E virus in Huh7 cells using in vitro CPE assay. Conclusion Our work presented a comprehensive systems pharmacology approach to identify the effective molecules and explore the molecular mechanism of XCHD against HCoVs.

Objective:To isolate and culture WU polyomavirus (WUPyV), and to analyze the genome-wide evolutionary patterns, homology and population dynamics.Methods:Real-time quantitative PCR was used to detect the nasopharyngeal aspirate samples of hospitalized children with respiratory tract infection in Beijing Friendship Hospital during 2020 to 2022. Primary human airway epithelial cells cultured at the air-liquid interface were used to isolate and culture WUPyV. Whole genome sequence of the isolated strain was obtained by Sanger sequencing. For phylogenetic and evolutionary dynamics analysis, the whole genome was compared with the published whole genome sequences in GenBank database.Results:The detection rate of WUPyV was 4.7% (31/659) during 2020 to 2022, and a clinical strain BJ0593 of WUPyV type Ⅲc was successfully isolated. The homology of the whole genome and gene fragments of WUPyV was high. The average evolutionary rate of VP2 gene was about 1.256×10 -4 substitution/site every year, and the population dynamics of WUPyV tended to be flat in the last decade. Conclusions:This study successfully isolated a clinical WUPyV type Ⅲ strain for the first time, which provided the basis for further investigation on the molecular evolution and pathogenicity of WUPyV.

BackgroundThis study aims to described the epidemiology and genotypic diversity of Human metapneumovirus (HMPV) and the impact of SARS-CoV-2 on the prevalence of HMPV in hospitalized children with Acute respiratory tract infections (ARTIs) in Beijing, China.MethodsFrom April 2018 to March 2019 and from September 2020 to August 2021, nasopharyngeal aspirates (NPAs) from hospitalized children with ARTIs in Beijing were collected and subjected to real-time polymerase chain reaction tests for HMPV. Then genotyping, detection of 15 common respiratory viruses and clinical characteristics were analyzed on HMPV positive samples.Results7.9% (124/1572) enrolled pediatric patients were identified as having HMPV infection, and the majority of children under the age of 5 (78.2%, 92/124), From April 2018 to March 2019. The detection rate of HMPV in spring and winter is significantly higher than that in summer and autumn. The co-infection rate were 37.1% (46/124), the most common co-infected virus were parainfluenza virus type 3 (HPIV-3). The main diagnosis of HMPV infection was pneumonia (92.7%,115/124), most patient have cough and fever. Of 78 HMPV-positive specimens, A2b (82.1%,64/78) were the main epidemic subtypes. Hospitalized children with HMPV genotype A infection had a higher viral load compared to genotype B. During the COVID-19 outbreak, Among 232 samples, only 4 cases were HMPV-positive. After statistical test, the detection rate of HMPV during the COVID-19 pandemic has decreased significantly compared with that before the epidemic (p = 0.001).ConclusionsHMPV is an important cause of ARTIs in children under 5 years old. The epidemic peak is generally in winter and spring, and the A2b subtype is the most common. However, under the prevention and control of the COVID-19 pandemic, the HMPV infection of hospitalized children with ARTIs has decreased significantly.

Abstract Background Among hospitalized children suffering from community-acquired pneumonia, Mycoplasma pneumoniae (MP) is one of the most common pathogens. MP often exists as a co-infection with bacteria or viruses, which can exacerbate the clinical symptoms. We investigated the pathogen spectrum in MP-positive and MP-negative samples from hospitalized children with respiratory tract infections in Beijing, China. Method This study included 1038 samples of nasopharyngeal aspirates obtained between April, 2017 and March, 2018 from hospitalized children under 6 years of age with respiratory tract infections. To explore the impact of MP infection on the composition of the pathogen spectrum, 185 nasopharyngeal aspirates (83 MP-positive/102 MP-negative) were randomly selected for next-generation sequencing and comprehensive metagenomics analysis. Real-time PCR was used to detect and verify common respiratory viruses. Results Of the 1038 samples, 454 (43.7%) were infected with MP. In children < 6 years of age, the MP infection rate gradually increased with age, with the highest rate of 74.2% in 5–6-year-olds. The results of metagenomics analysis revealed 11 human, animal and plant virus families, and bacteriophages, including common respiratory viruses, enteroviruses and anelloviruses. The virus family with the highest number of reads in both MP-positive and MP-negative samples was the Pneumoviridae, and the number of reads for human respiratory syncytial virus (HRSV) in MP-positive samples was higher than that in MP-negative samples. Among the 83 MP-positive samples, 47 (56.63%) were co-infected with viruses, the most common of which was influenza virus (IFV). The durations of hospitalization and fever were higher in patients with MP co-infection than MP single infection, but the difference was not statistically significant. Conclusion The viral family with the highest number of reads in both groups was Pneumoviridae, and the number of reads matched to HRSV in MP-positive samples was much higher than MP-negative samples. Co-infection of MP and IFV infection were the most cases.

Objective:To investigate the epidemiological characteristics of human bocavirus 1 (HBoV1) and to analyze the genetic variation.Methods:A total of 2 848 nasopharyngeal aspirate (NPAs) specimens were collected from hospitalized children with acute respiratory tract infections (ARTI) in Beijing Friendship Hospital from April 2017 to March 2019, and HBoV1 was detected by quantitative real-time PCR. Epidemiological analysis was carried out based on the clinical information of the patients. The nested PCR method was used to amplify the NP1 and VP1 genes of HBoV1 for homology analysis. Maximum clade credibility tree (MCC tree) and genetic polymorphism map were constructed to analyze the time evolution of HBoV1 VP1.Results:HBoV1 was detected in 90(3.16%) of 2 848 NPAs, most (93.33%, 84/90) HBoV1-positive cases were among children <5 years of age. HBoV1 could be detected throughout the year with a higher prevalence 7.23% (18/249) in October. Of the 90 HBoV1-infected cases, the main clinical symptoms were fever and cough, 44(48.89%) were co-infected with other respiratory viruses; 55 NP1 sequences and 47 VP1 sequences were obtained by nested PCR amplification, phylogenetic analysis showed that the nucleotide homology was 98.9%~-100% and 99.1%~-100%, respectively. MCC tree showed that the HBoV1 VP1 gene sequence obtained in this study appeared in two adjacent clades, the gene evolution was stable.Conclusions:HBoV1 is one of the common viruses that cause respiratory infection among children in Beijing. HBoV1 genetic evolution is relatively stable, but it still needs to be monitored continuously.

目的 针对致死率极高的尼帕病毒,制备安全、稳定的含有尼帕病毒N基因片段的重组假病毒颗粒阳性标准品.方法 人工合成含有尼帕病毒N基因片段的核苷酸序列并导入CD513B慢病毒载体,与包装质粒同时转染HEK293T细胞,超速离心浓缩纯化,电镜观察假病毒颗粒形态,感染实验验证假病毒功能,并进行线性、稳定性和均一性检测.结果 包装并纯化后的假病毒颗粒浓度较高,直径在100～200 nm,可见明显的G蛋白刺突,感染实验绿色荧光蛋白信号强且不同温度下储存稳定性良好,均一性检测变异系数小于1％.结论 成功构建含有尼帕病毒N基因片段的假病毒颗粒,可作为阳性对照品在尼帕病毒核酸提取和检测过程中实现全程质量控制.

Objective:To construct 2019 novel coronavirus (2019-nCoV) 614D and 614G pseudovirus by HIV lentivirus packaging system and explore their biological specificity.Methods:The recombinant expression plasmids pCDNA3.1-614D and pCDNA3.1-614G were transiently cotransfected with psPAX2 and pLenti CMV Puro LUC into 293T cells respectively. After 72 hours, the supernatant was collected and ultracentrifuged with 20% sucrose cushion. The titer, morphology, protein expression and neutralizing activity of pseudovirus were determined.Results:S protein specific fluorescence was detected by indirect immunofluorescence test, Western blot analysis showed S protein was expressed, and the spike of pseudovirus was observed under transmission electron microscope. The titers of pseudovirus 614D and 614G were 1.12×10 4 and 2.52×10 4 TCID 50/ml, respectively. The pseudovirus 614D and 614G could be neutralized by S rabbit polyclonal antibody, indicating that the pseudovirus has high specificity. Conclusions:In this study, 2019-nCoV 614D and 614G pseudovirus was successfully constructed, which laid the foundation for the establishment of in vitro neutralizing antibody detection platform based on pseudovirus.

人偏肺病毒(Human metapneumovirus,HMPV)是2001年鉴定出的新发呼吸道病毒,婴幼儿、老人和免疫抑制人群易感,引起上呼吸道和下呼吸道感染,目前尚无疫苗和特异性治疗方案.为获得北京地区HMPV临床流行毒株,本研究将经荧光定量PCR检测为HMPV阳性的鼻咽抽吸物样本分别接种LLC-MK2、Vero-E6和分化良好的人呼吸道上皮细胞(Human Airway Epithelium,HAE),观察细胞病变、检测免疫荧光、电镜观察病毒形态、测定病毒滴度及分析复制特点,对分离获得的HMPV分离株进行鉴定.结果表明,HMPV感染LLC-MK2细胞可形成合胞体,但在Vero-E6中多呈单个细胞感染;经免疫荧光检测,HAE、LLC-MK2和Vero-E6细胞均可见绿色荧光;电镜结果可见病毒为近似球型的颗粒,有包膜和刺突,直径约在150nm～200nm之间;HMPV在HAE和LLC-MK2两种细胞上的复制特点基本相同.本研究成功建立了临床样本在LLC-MK2、Vero-E6和HAE分离培养HMPV的方法,分离并鉴定了 HMPV临床分离株,为HMPV感染机制的研究奠定基础.

Background Human adenoviruse (HAdV) is a major pathogen of paediatric respiratory tract infections (RTIs). Mutation or recombination of HAdV genes may cause changes in its pathogenicity and transmission. We described the epidemiology and genotypic diversity of HAdV in hospitalized children with RTIs in Beijing, China. Methods Nasopharyngeal aspirates were collected from hospitalized children with RTIs from April 2018 to March 2019. HAdVs were detected by a quantitative real-time PCR, and the hexon gene was used for phylogenetic analysis. Results Among 1572 samples, 90 (5.72%) were HAdV-positive. The HAdV detection rate was highest in November and July. Among HAdV-positive children, 61.11% (55/90) were co-infected with other respiratory viruses, the most common of which were human respiratory syncytial virus and human rhinovirus. The main diagnosis was bronchopneumonia, most patient have cough and fever. Children with a high viral load were more likely to have a high fever ( P = 0.041) and elevated WBC count ( P = 0.000). Of 55 HAdV-positive specimens, HAdV-B (63.64%), HAdV-C (27.27%), and HAdV-E (9.09%) were main epidemic species. Phylogenetic analysis indicated that hexon sequences of three samples were on the same branch with the recombinant HAdV strain (CBJ113), which was circulating in Beijing since 2016. Conclusion The HAdV-B3 and HAdV-B7 are the main epidemic strains in Beijing, and the recombinant HAdV-C strain CBJ113 has formed an epidemic trend.