Objective:To analyze antiviral activity against respiratory syncytial virus (RSV) of interferon (IFN)-α2b and IFN-λ1 on Hep2 cells and human airway epithelial (HAE) cells.Methods:IFN-α2b or IFN-λ1 was incubated with Hep2 cells after RSV infection, and 48 hours later, the cytopathic effect was observed, the viral load was determined using real time/reverse transcription quantitative polymerase chain reaction (RT qPCR), RSV F protein expression was detected using immunofluorescence, and cell survival rate was detected using crystal violet. HAE cells were incubated with IFN-α2b or IFN-λ1 for 24 hours, and then HAE were challenged with RSV. The viral load in the culture supernatant was determined on days 1-7 using RT qPCR, RSV F protein was determined with immunofluorescence and the viral titers in the culture supernatant was detected on day 7 by plaque assay.Results:In Hep2 cells, the CPE of the treatment groups (IFN-α2b and IFN-λ1) was alleviated compared to the virus control group, and the CPE of the high concentration group was lighter than that of the low concentration group. Different concentrations of IFN-α2b and IFN-λ1 could significantly reduce the viral load of RSV ( P<0.001), and the viral load of the high concentration group was significantly lower than that of the low concentration group ( P<0.001). In addition, IFN-α2b and IFN-λ1 could reduce the RSV F protein expression after RSV infection and improve cell survival rate. In HAE cells, IFN-α2b and IFN-λ1 could inhibit RSV virus replication, reduce virus titers ( P<0.001) and reduce RSV F protein expression. Conclusions:IFN-α2b and IFN-λ1 both showed great antiviral activity against RSV in Hep2 and HAE cells, providing data reference for the study of interferon against respiratory viruses.

Objective:To explore the feasibility of bibliometric analysis of research papers on human metapneumovirus based on Web of Science database.Methods:The human metapneumovirus (HMPV) causes a serious disease burden worldwide. This article used bibliometric analysis method to search for papers using the keyword " metapneumovirus" , and searched for HMPV papers published from 2001 to 2023 in the Web of Science database. Statistical analysis of the distribution of papers on HMPV by year, country, journal, research institution, author, etc., in order to understand the current research status and development trends of HMPV in the international community.Results:A total of 3 282 papers were retrieved, of which 97% were in English. HMPV was first reported in 2001, and since then, research papers have been increasing year by year. The United States has the highest number of published papers, with China, the United Kingdom, France, and the Netherlands ranked 2nd, 3rd, 4th, and 5th respectively. The field of virology-general had the highest number of papers. In terms of research institution distribution, Vanderbilt University in the United States has published 135 papers, ranked the first. The journal which had the highest number of published papers was JOURNAL OF MEDICAL VIROLOGY, with a total of 143 papers. The author Williams JV of Vanderbilt University in the United States has published 92 papers, indicating its high international status in the field of HMPV research.Conclusions:Among the retrieved HMPV related papers, research institutions and universities in European and American countries have published more papers.

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.

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.

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.

Objective:To establish a quick and convenient method for detecting human adenoviruses (Human adenoviruses, HAdV) based on immunochromatographic assay (ICA).Methods:Two antibody clones, 3C11 and 7E6 were found to bind to all tested HAdVs and then subsequently processed into ICA. The specificity and sensitivity were evaluated using representative strains of the respiratory HAdV types, including HAdV-1, 2, 3, 4, 5, 6, 7, 10 and a gastroenteric type HAdV-41 together with the original throat swabs of 10 HAdV patients confirmed by nuclear acid testing (NAT).Results:The ICA exhibited high specificity to HAdVs and its detection limitation ranged from 0.16 to 10 3 half tissue culture infectious dose (TCID 50)/ml for different types of HAdVs. All clinic samples with successful virus isolation tested by this ICA showed positive result . Conclusions:The ICA developed in the present study will be suitable for HAdVs screening in clinic setting, especially for those of respiratory types.

Objective:To find clues potentially valuable for fighting against infection with human respiratory syncytial virus (HRSV), the differentially expressed genes in HEp-2 cells infected with HRSV were analyzed.Methods:Gene expression profiles of HEp-2 cells infected with HRSV were collected from the public gene expression omnibus (GEO) database. The differentially expressed genes following HRSV infection at each time point of 4, 8, 12, and 15 hours were found using R language. The differentially expressed genes were analyzed by gene ontology (GO), KEGG pathway and protein-protein interaction network (PPI). Genes with relatively high protein interaction in PPI were randomly selected for quantitative reverse transcription-polymerase chain reaction (qRT-PCR) verification at the transcription level from HEp-2 cells after HRSV infection at 4 hours.Results:A total of 101 differentially expressed genes were determined, including 92 upregulated genes and 9 downregulated genes. Function enrichment analysis revealed that HRSV infection could cause significant changes in multiple signaling pathways such as immune response in HEp-2 cells. The results of qRT-PCR were consistent with the trend of transcriptome data.Conclusions:The differentially expressed genes and the change of signaling pathways in HRSV-infected HEp-2 cells is of great significance to the studies on pathogenic mechanism and prevention of HRSV infection.

Objective:To evaluate the effectiveness of three laboratory routine disinfection methods on influenza virus inactivation.Methods:The physical method of ultraviolet irradiation and two chemical methods of ethanol and "84 disinfectant" were used to inactivate the influenza virus respectively. After disinfecting the virus samples at different times or concentrations, MDCK cells were inoculated and the inactivation effect of influenza virus was identified by observing cytopathic effect (CPE).Results:When the influenza virus was irradiated by ultraviolet light for ≥1 min, treated with 75% ethanol for 0.25-32 min, the effective chlorine concentration of "84 disinfectant" was ≥400 mg/L, and the influenza virus was disinfected at room temperature for ≥1 min, no virus infectivity could be detected under the three conditions.Conclusions:The condition of inactivating influenza virus by routine disinfection methods in laboratory was explored, which provided reference data for establishing the protection specifications and the emergency treatment plans for influenza virus laboratories.

Objective:To study the sequence characteristics and genetic variation of a human respiratory syncytial virus (HRSV) subtype A genome in Beijing.Methods:The genomic RNA of HRSV from nasopharyngeal aspirate samples was sequenced and obtained a whole genome sequence of HRSV A subtype. The phylogenetic tree was constructed with reference sequences of other HRSV strains. The major proteins were compared and single nucleotide polymorphism analyzed. In addition, the N-glycosylationsites of F and G protein were predicted.Results:Phylogenetic tree and homology analysis results suggest that the HRSV strain (RSVA/Beijing-China/2017) was the A subtype ON1 genotype. Nucleotide and amino acid variation analysis showed that G protein, F protein and L protein had some substitutions. Analysis of amino acid variation sites showed that amino acid substitution (L142S) occurred at position 142 of G protein. For F protein, there were two substitutions, which were S105N in the P27 peptide (110-136aa) and C69Y in the antigen sites ? (62-69 aa and 196-210 aa). The prediction of N-glycosylation sites revealed that there were 5 N-glycosylation sites of F protein and 4 N-glycosylation sites of G protein in this strain.Conclusions:The HRSV strain obtained in Beijing belongs to A subtype ON1 genotype. The G, F and L proteins have large variations, and 22 amino acid substitutions have occurred in the G and F proteins.

Objective:To retrospectively analyze the clinical characteristics of elderly patients who received colonoscopy and to explore the clinical value of regular colonoscopy for the elderly.Methods:This was a retrospective cohort study.A total of 1 154 patients aged 75 years and over undergone colonoscopy in Guangdong General Hospital from January 2015 to March 2018 were enrolled and divided into three groups, including 605 cases aged 75-79 years, 527 cases aged 80-89 years and 22 cases aged 90 years and over.Detection rates of colorectal lesions by colonoscopy were recorded.The clinical value of annual colonoscopy on the detection of colorectal lesions in elderly patients 75 years and older were analyzed to assess the necessity for regular monitoring.Results:Overall, 569 cases(49.3%)underwent colonoscopy with sedation and 585 cases(50.7%)underwent colonoscopy without sedation.The total positive detection rate was 83.4%(962/1 154), and the main lesions were polyps(858 cases, 74.4%), including 605(52.4%)cases of adenomas.Among the three groups, gastrointestinal bleeding was the main cause for colonoscopy in the group aged 90 years and over, while abdominal discomfort, elevated immunological tumor markers and history of non-colon cancer were the main reasons for colonoscopy in the group aged 75-79 years( P<0.05). A total of 153 cases underwent annual colonoscopy.The detection rate of polyps and adenomas decreased in the second exam, but still higher than 40.0%. Conclusions:Colonoscopy is a safe and effective method for the elderly population aged 75 years and over.Polyps and adenomas are the most common lesions.Recurrence of polyps after colorectal cancer and polypectomy is common and it is necessary to receive colonoscopy regularly.