OBJECTIVES: To investigate the effect of interferon-λ1 (IFN-λ1) on glucocorticoid (GC) resistance in human bronchial epithelial cells (HBECs) stimulated by respiratory syncytial virus (RSV). METHODS: HBECs were divided into five groups: control, dexamethasone, IFN-λ1, RSV, and RSV+IFN-λ1. CCK-8 assay was used to measure the effect of different concentrations of IFN-λ1 on the viability of HBECs, and the sensitivity of HBECs to dexamethasone was measured in each group. Quantitative real-time PCR was used to measure the mRNA expression levels of p38 mitogen-activated protein kinase (p38 MAPK), glucocorticoid receptor (GR), and MAPK phosphatase-1 (MKP-1). Western blot was used to measure the protein expression level of GR in cell nucleus and cytoplasm, and the nuclear/cytoplasmic ratio of GR was calculated. RESULTS: At 24 and 72 hours, the proliferation activity of HBECs increased with the increase in IFN-λ1 concentration in a dose- and time-dependent manner (P˂0.05). Compared with the RSV group, the RSV+IFN-λ1 group had significant reductions in the half-maximal inhibitory concentration of dexamethasone and the mRNA expression level of p38 MAPK (P<0.05), as well as significant increases in the mRNA expression levels of GR and MKP-1, the level of GR in cell nucleus and cytoplasm, and the nuclear/cytoplasmic GR ratio (P<0.05). CONCLUSIONS IFN-λ1 can inhibit the p38 MAPK pathway by upregulating MKP-1, promote the nuclear translocation of GR, and thus ameliorate GC resistance in HBECs.
Humans ; p38 Mitogen-Activated Protein Kinases/genetics* ; Glucocorticoids/pharmacology* ; Receptors, Glucocorticoid/analysis* ; Dual Specificity Phosphatase 1/physiology* ; Dexamethasone/pharmacology* ; Drug Resistance/drug effects* ; Respiratory Syncytial Viruses ; Interferons/pharmacology* ; MAP Kinase Signaling System/drug effects* ; Epithelial Cells/drug effects* ; Signal Transduction/drug effects* ; Cells, Cultured

OBJECTIVES: To investigate the epidemiological characteristics of human metapneumovirus (hMPV) and the risk factors for severe pneumonia in hospitalized children. METHODS: The epidemiological characteristics of hMPV in hospitalized children at Hebei Children's Hospital from January 2019 to December 2023 were retrospectively analyzed. The clinical data of hospitalized children with hMPV infection from April to December 2023 were included, and independent risk factors for severe pneumonia were identified through logistic regression. RESULTS: A total of 44 092 children were tested, with an hMPV positive rate of 7.30% (3 220/44 092). Children aged 3-6 years constituted the largest proportion (40.93%, 1 318/3 220) among hMPV-positive cases. The detection rate varied significantly by year (P<0.001), peaking in 2022 (12.35%, 978/7 919). The peak season of the epidemic was winter and spring from 2019 to 2021, but shifted to spring and summer from 2022 to 2023. The proportion of co-infection was 38.70% (1 246/3 220), primarily with rhinovirus (600/1 246, 48.15%), Mycoplasma pneumoniae (217/1 246, 17.42%), and respiratory syncytial virus (182/1 246, 14.61%). The main manifestations of hMPV pneumonia were cough, expectoration, and fever. Children with severe pneumonia were significantly younger (P<0.05). Wheezing, underlying diseases, co-infection, and younger age were identified as independent risk factors for severe pneumonia (P<0.05). CONCLUSIONS There are significant annual and seasonal differences in the epidemiological characteristics of hMPV in hospitalized children. Young age, underlying diseases, wheezing, and co-infection are independent risk factors for severe pneumonia.
Humans ; Risk Factors ; Metapneumovirus ; Child, Preschool ; Child ; Male ; Female ; Paramyxoviridae Infections/complications* ; Pneumonia/epidemiology* ; Retrospective Studies ; Child, Hospitalized ; Infant ; Logistic Models ; Seasons ; Hospitalization

Paramyxoviruses are important respiratory pathogens with substantial clinical relevance in pediatric infectious diseases. During infection, multiple forms of programmed cell death (PCD) may be induced, and this plays pivotal roles in viral replication, dissemination, and host immune responses, thereby profoundly influencing the viral life cycle and disease progression. On one hand, PCD facilitates the clearance of infected cells, restricts viral spread, and activates host immune defenses, thereby enhancing antiviral immunity. On the other hand, excessive or dysregulated cell death may lead to tissue damage and immune imbalance, creating a microenvironment conducive to viral replication and exacerbating disease severity. For instance, apoptosis-mediated by both extrinsic and intrinsic pathways-contributes to infection control but may also be hijacked by viruses to promote dissemination. Pyroptosis, driven by inflammasome activation, triggers lytic cell death and the release of pro-inflammatory cytokines. Necroptosis, mediated by the RIPK1-RIPK3-MLKL signaling axis, and pyroptosis both amplify innate immune responses but may concurrently induce inflammatory dysregulation. Immunogenic cell death (ICD), characterized by the release of damage-associated molecular patterns and neoantigens, activates antigen-specific immune responses and holds therapeutic potential for antiviral and antitumor interventions. Emerging evidence suggests that ferroptosis, through the modulation of iron metabolism and associated transporters, may also participate in viral replication and infected cell clearance. This review comprehensively summarizes the roles of apoptosis, pyroptosis, necroptosis, ICD, and ferroptosis in paramyxovirus infection, aiming to deepen the understanding of paramyxovirus pathogenesis and to provide insights for developing novel antiviral strategies.
Humans ; Paramyxoviridae Infections/pathology* ; Pyroptosis ; Apoptosis ; Virus Replication ; Necroptosis ; Inflammasomes ; Immunity, Innate ; Immunogenic Cell Death ; Paramyxoviridae/physiology* ; Signal Transduction

Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

Seven novel acylphloroglucinol-sesquiterpenoid adducts, designated as dryatraols J-P (1-7), were isolated from the rhizomes of Dryopteris atrata (Wall. ex Kunze) Ching. The structures, including absolute configurations, were elucidated using comprehensive spectroscopic data, calculated ¹³C Nuclear Magnetic Resonance-Diastereotopic Probability Assignment Plus (¹³C NMR-DP4+) probability analysis, and ECD calculations. These structures represent a rare subclass of carbon skeleton of acylphloroglucinol-sesquiterpenoid adducts with a furan ring connecting the acylphloroglucinol and sesquiterpenoid moieties. Notably, compounds 1-6 are the first reported examples of acylphloroglucinol-sesquiterpenoid adducts with dimeric acylphloroglucinol incorporated into the aristolane- or rulepidanol-type sesquiterpene, while compound 7 features a hydroxylated monomeric acylphloroglucinol motif. A preliminary evaluation of their antiviral activities revealed that compounds 1-6 exhibited more potent activities against respiratory syncytial virus (RSV) with IC₅₀ values ranging from 0.75 to 3.12 μmol·L^-1 compared to the positive control (ribavirin).
Antiviral Agents/isolation & purification* ; Phloroglucinol/isolation & purification* ; Sesquiterpenes/isolation & purification* ; Molecular Structure ; Dryopteris/chemistry* ; Respiratory Syncytial Viruses/drug effects* ; Humans ; Rhizome/chemistry* ; Drugs, Chinese Herbal/pharmacology*

Peganum harmala L. (P. harmala) is a significant economic and medicinal plant. The seeds of P. harmala have been extensively utilized in traditional Chinese medicine, Uighur medicine, and Mongolian medicine, as documented in the Drug Standard of the Ministry of Health of China. Twelve novel tryptamine-derived alkaloids (1-12) and eight known compounds (13-20) were isolated from P. harmala seeds. Compounds 1 and 2 represent the first reported instances of tryptamine-derived heteromers, comprising tryptamine and aniline fragments with previously undocumented C-3-N-1' linkage and C-3-C-4' connection, respectively. Compounds 3-5 were identified as indole-quinazoline heteromers, exhibiting a novel C-3 and NH-1' linkage between indole and quinazoline-derived fragments. Compound 6 demonstrates the dimerization pattern of C-C linked tryptamine-quinazoline dimer. Compound 8 represents a tryptamine-derived heterodimer with a distinctive carbon skeleton, featuring an unusual spiro-tricyclic ring (7) and conventional bicyclic tryptamine. Compounds 9-11 constitute novel 6/5/5/5 spiro-tetracyclic tryptamine-derived alkaloids presenting a unique ring system of tryptamine-spiro-pyrrolizine. Compounds 1-3 and 6-11 were identified as racemates. Compounds 2, 7, 9, 10, and 12 were confirmed via X-ray crystallographic analysis. All isolated compounds (1-20) exhibited varying degrees of antiviral efficacy against respiratory syncytial virus (RSV). Notably, the anti-RSV activity of compound 12 (IC₅₀ 5.01 ± 0.14 μmol·L^-1) surpassed that of the positive control (ribavirin, IC₅₀ 6.23 ± 0.95 μmol·L^-1), as validated through plaque reduction and immunofluorescence assays. The identification of anti-RSV compounds from P. harmala seeds may enhance the development and application of this plant in antiviral therapeutic products.
Antiviral Agents/isolation & purification* ; Tryptamines/isolation & purification* ; Peganum/chemistry* ; Seeds/chemistry* ; Alkaloids/isolation & purification* ; Molecular Structure ; Humans ; Respiratory Syncytial Viruses/drug effects* ; Plant Extracts/pharmacology* ; Drugs, Chinese Herbal/pharmacology*

Respiratory syncytial virus (RSV) is an enveloped, negative-sense, single-stranded RNA virus of the Orthopneumovirus  genus of the Pneumoviridae family in the order Mononegavirales. RSV can cause acute upper and lower respiratory tract infections, sometimes with extrapulmonary complications. The disease burden of RSV infection is enormous, mainly affecting infants and older adults aged 75 years or above. Currently, treatment options for RSV are largely supportive. Prevention strategies remain a critical focus, with efforts centered on vaccine development and the use of prophylactic monoclonal antibodies. To date, three RSV vaccines have been approved for active immunization among individuals aged 60 years and above. For children who are not eligible for these vaccines, passive immunization is recommended. A newly approved prophylactic monoclonal antibody, Nirsevimab, which offers enhanced neutralizing activity and an extended half-life, provides exceptional protection for high-risk infants and young children. This review provides a comprehensive and detailed exploration of RSV's virology, immunology, pathogenesis, epidemiology, clinical manifestations, treatment options, and prevention strategies.
Humans ; Respiratory Syncytial Virus Infections/prevention & control* ; Respiratory Syncytial Viruses/pathogenicity* ; Respiratory Syncytial Virus, Human/pathogenicity* ; Antiviral Agents/therapeutic use*

Nipah virus (NiV) is a zoonotic paramyxovirus that has recently emerged as a crucial public health issue. It can elicit severe encephalitis and respiratory diseases in animals and humans, leading to fatal outcomes, exhibiting a wide range of host species tropism, and directly transmitting from animals to humans or through an intermediate host. Human-to-human transmission associated with recurrent NiV outbreaks is a potential global health threat. Currently, the lack of effective therapeutics or licensed vaccines for NiV necessitates the primary utilization of supportive care. In this review, we summarize current knowledge of the various aspects of the NiV, including therapeutics, vaccines, and its biological characteristics, epidemiology, pathogenesis, and clinical features. The objective is to provide valuable information from scientific and clinical research and facilitate the formulation of strategies for preventing and controlling the NiV.
Animals ; Humans ; Disease Outbreaks/prevention & control* ; Henipavirus Infections/virology* ; Nipah Virus/pathogenicity* ; Viral Vaccines ; Zoonoses/virology*

This study aimed to develop a portable, accurate and easy-to-operate scheme for rapid detection of respiratory virus nucleic acid. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the effect of extraction-free respiratory virus treatment reagent (RTU) on viral nucleic acid treatment and the effect of ultra-fast fluorescence quantitative PCR instrument (FQ-8A) on nucleic acid amplification, respectively. RTU and FQ-8A were combined to develop a rapid detection scheme for respiratory virus nucleic acid, and the positive detection rate was judged by C_t value using a fluorescence quantitative PCR instrument, and the accuracy of the scheme in clinical samples detection was investigated. The results showed that RTU had comparable sensitivity to the automatic nucleic acid extraction instrument, its extraction efficiency was comparable to the other 3 extraction methods when extracting samples of different virus types, but the extraction time of RTU was less than 5 min. FQ-8A had good consistency in detection respiratory syncytial virus (RSV) and adenovirus (ADV) compared with the control instrument ABI-7500, with kappa coefficients of 0.938 (P < 0.001) and 0.887 (P < 0.001), respectively, but the amplification time was only about 0.5 h. The RTU and FQ-8A combined rapid detection scheme had a highly consistent detection rate with the conventional detection scheme, with a sensitivity of 91.70% and specificity of 100%, and a kappa coefficient was 0.944 (P < 0.001). In conclusion, by combining RTU with FQ-8A, a rapid respiratory virus nucleic acid detection scheme was developed, the whole process could be completed in 35 min. The scheme is accurate and easy-to-operate, and can provide important support for the rapid diagnosis and treatment of respiratory virus.
Humans ; Respiratory Syncytial Virus Infections/diagnosis* ; Respiratory Syncytial Virus, Human/genetics* ; Nucleic Acid Amplification Techniques ; Real-Time Polymerase Chain Reaction ; Adenoviridae ; Sensitivity and Specificity

A simple, fast, and visual method for detecting antibodies against peste des petits ruminants virus (PPRV) using colloidal gold strips was developed. In this study, the pET-32a-N was transformed into Escherichia coli Rosetta (DE3) for expression. Hybridoma cell lines were generated by fusing SP2/0 myeloma cells with splenocytes from immunized mice with the expressed and purified N protein of PPRV. The PPRV N protein was labeled with colloidal gold particles as the gold-labeled antigen. The N protein served as the gold standard antigen and as the test (T) line-coated antigen, while the monoclonal antibody served as the quality control (C) line-coated antibody to assemble the colloidal gold immunochromatographic test strips for detecting antibodies against the N protein of PPRV. Hybridoma cell line designated as 1F1 was able to stably secrete the monoclonal antibody against the N protein of PPRV. The titer of 1F1 monoclonal antibody in ascites was 1:128 000 determined by indirect enzyme-linked immunosorbent assays (ELISA), and the immunoglobulin subtype of the monoclonal antibody was IgG1, with kappa chain. The obtained monoclonal antibody was able to specifically recognize the N protein of PPRV, as shown by Western blotting and indirect immunofluorescent assay (IFA). The developed colloidal gold test strip method was able to detect PPRV antibodies specifically, and there was no difference between different batches of the test strips. Testing of a total of 122 clinical sera showed that the compliance rate of the test strip with ELISA test was 97.6%.The test strip assay developed in this study has good specificity, reproducibility, and sensitivity, and it can be used for the rapid detection of PPRV antibodies.
Animals ; Mice ; Peste-des-Petits-Ruminants/prevention & control* ; Antibodies, Monoclonal ; Reproducibility of Results ; Peste-des-petits-ruminants virus ; Antibodies, Viral ; Enzyme-Linked Immunosorbent Assay ; Goats