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.

干扰素诱导跨膜蛋白3 (Interferon-induced transmembrane protein 3,IFITM3)的单核苷酸突变位点(Single-nucleotide polymorphism,SNP) rs12252-C在中国人群的比例高,与流感病毒H1N1/09感染后疾病的严重性相关.本文主要探索流感病毒三价灭活疫苗(Trivalent inactivated vaccine,TIV)免疫IFITM3敲除小鼠后机体免疫反应的变化.采用转录激活因子样效应物核酸酶(Transcription activator-like effector nucleases,TALENs)技术构建IFITM3敲除小鼠模型,TIV肌肉注射免疫小鼠,使用流式细胞术检测小鼠脾脏的获得性免疫细胞,如T细胞、B细胞,以及固有免疫细胞,如自然杀伤细胞(Natural killer cell,NK细胞)、树突状细胞(Dendritic cell,DC)、巨噬细胞(Macrophage,Mφ)、中性粒细胞等的数量变化情况.TIV免疫后7d,IFIMT3敲除小鼠脾脏CD8+T细胞、NK细胞的数量和活化水平升高,生发中心(Germinal center,GC)的B细胞数量下降,CD4+T细胞、DC、Mφ、中性粒细胞的数量没有显著变化.本研究提示,IFITM3敲除影响了TIV免疫后小鼠脾脏免疫细胞的数量和活化水平,为IFITM3与免疫反应的关系研究奠定了基础.

目的 了解2017年北京市朝阳区流感样病例(influenza-like illness,ILI)病原谱和人偏肺病毒(human metapneumovirus,hMPV)感染情况.方法 收集2017年1-12月ILI样本,使用荧光定量PCR检测10种常见呼吸道病原体,包括流感病毒、鼻病毒、支原体等,对偏肺病毒阳性样本进行分型检测.结果 2 189份ILI样本中检出639份阳性样本.病原谱构成前四位为流感病毒、鼻病毒、支原体和副流感病毒;共检出16份hMPV样本,主要在冬春季流行,分型结果显示有5份B1亚型和1份A2亚型.结论 流感病毒、鼻病毒、支原体和副流感病毒是2017年朝阳区ILI的主要病原体;hMPV流行具有季节性,并以B1亚型流行为主.

北京市朝阳区在连续40d没有新增本土COVID-19确诊病例的情况下,出现了1例潜伏期超过14d的境外回国COVID-19确诊病例.为分析北京市朝阳区1例COVID-19患者是否为输入病例,进行了全基因组序列测定和遗传特性分析,本研究采用高通量测序技术配合Ion Torrent系列仪器和试剂对患者咽拭子中的SARS-CoV-2进行测序,同时应用对应插件或软件分析其全基因组同源性和变异情况.结果 显示,该病例标本中测得1株SARS-CoV-2毒株,共29 876 bp,BLAST结果显示与其他国家和地区分离株的相似性高于与中国分离株的相似性.系统进化树中该毒株与2003年感染人的SARS冠状病毒和蝙蝠中分离的SARS冠状病毒明显不同,分处不同进化分支;该毒株与中国分离株分处不同的簇,而和美国分离株聚集在一簇.另外,突变分析显示存在3个改变氨基酸性质的非同义突变.本研究提示,该病例为美国输入的SARS-CoV-2感染病例,应注意境外输入性COVID-19的传播,并适当延长隔离观察期限;该毒株在患者的1例关联病例中发生了部分核苷酸突变,对SARS-CoV-2的致病力等的影响有待进一步研究.

Interferon-induced transmembrane protein 3 (IFITM3) as an antiviral factor can inhibit replication of several viruses including influenza virus. A single-nucleotide polymorphism rs12252-C of IFITM3 results in a truncated IFITM3 protein lacking its first 21 amino acids, which is much higher in the Han Chinese population and associated with severe illness in adults infected with pandemic influenza H1N1/09 virus. To investigate if IFITM3 or IFITM3 rs12252-C could affect the antibody response after influenza vaccination, we detected the haemagglutination inhibition (HI) of 171 healthy young adult volunteers (IFITM3 rs12252-C/C, C/T, T/T carriers) and in an IFITM3-deletion mouse model (Ifitm3(-/-)) after trivalent inactivated vaccine (TIV) immunization. Seroconversion rates for H1N1, H3N2 and B viruses in IFITM3 rs12252-C/C genotype carriers was lower compared with C/T and T/T donors. Significantly lower levels of specific antibodies to H1N1, H3N2 and B viruses and total IgG were observed in Ifitm3(-/-) mice. Correspondingly, the numbers of splenic germinal centre (GC) B cells, plasma cells, TIV-specific IgG(+) antibody secreting cells and T follicular helper cells in Ifitm3(-/-) mice were lower compared with wild type mice. However, the number of memory B cells was higher in Ifitm3(-/-) mice at day 7 after booster. The HI level of Ifitm3(-/-) mice remained lower than WT mice after third vaccination. Moreover, the transcriptional network regulating GC B cell and plasma cell differentiation was abnormal in Ifitm3(-/-) mice. Our results indicate that IFITM3 deletion attenuated the antibody response. The mechanism of influenza-IFITM3 interactions affecting the antibody response requires further investigation.

Objective Interferon-induced transmembrane protein 3 (IFITM3) is an important member of the IFITM family. However, the molecular mechanisms underlying its antiviral action have not been completely elucidated. Recent studies on IFITM3, particularly those focused on innate antiviral defense mechanisms, have shown that IFITM3 affects the body's adaptive immune response. The aim of this study was to determine the contribution of IFITM3 proteins to immune control of influenza infection in vivo. Methods We performed proteomics, flow cytometry, and immunohistochemistry analysis and used bioinformatics tools to systematically compare and analyze the differences in natural killer (NK) cell numbers, their activation, and their immune function in the lungs of Ifitm3-/- and wild-type mice. Results Ifitm3-/- mice developed more severe inflammation and apoptotic responses compared to wild-type mice. Moreover, the NK cell activation was higher in the lungs of Ifitm3-/- mice during acute influenza infection. Conclusions Based on our results, we speculate that the NK cells are more readily activated in the absence of IFITM3, increasing mortality in Ifitm3-/- mice.

干扰素诱导的跨膜蛋白3 (Interferon-induced transmembrane protein 3,IFITM3)敲除小鼠(Ifitm3-/-小鼠)感染流感病毒后,表现出更为严重的病理损伤和死亡率.最近的研究发现,IFITM3蛋白表达也会影响机体针对流感病毒的适应性免疫反应效果.由于空间效应,纵膈淋巴结在机体抵抗流感病毒急性期感染的适应性免疫应答过程中发挥重要功能,本研究欲探究使用流感病毒鼠肺适应株A/PR/8/H1N1进行感染后,野生型和Ifitm3-/-小鼠的纵膈淋巴结中与免疫相关的差异表达基因.本研究对流感病毒PR8感染后第3d的纵膈淋巴结进行RNA-Seq测序.高通量测序共检测到有1 312个差异表达基因,其中上调和下调差异表达基因分别为904和408个.这些差异表达基因主要参与炎症反应与细胞凋亡信号通路、T细胞和B细胞受体信号通路、T细胞和B细胞激活与细胞因子分泌等信号通路.采用荧光定量PCR对部分免疫相关的差异表达基因进行验证,结果与RNA-Seq测序结果一致.本研究为进一步阐明IFITM3在适应性免疫应答中拮抗流感病毒的分子机制奠定了基础.

目的 了解北京市朝阳区流感样病例(ILI)病原谱及流行特征.方法 采集2017年在2家哨点医院就诊的ILI的咽拭子,采用荧光PCR法检测20种呼吸道病原.采用x2检验或Fisher确切概率法比较不同性别、年龄及月份中ILI的病原体检出情况.结果 共收集ILI样本2 189份,单一病原感染总阳性率为28.86％(628/2 189),排在前四位的是流感病毒(19.64％)、人鼻病毒(2.38％)、支原体(1.51％)和副流感病毒(1.19％);男、女及不同年龄段ILI的检出率差异均有统计学意义(P ＜0.05);病原检出率在1月-2月、8月-9月、12月出现高峰,且不同月份ILI的检出率差异有统计学意义(P＜0.05).混合感染阳性率为0.77％(11/2 189),以流感病毒合并其他病毒感染为主.结论 2017年该地区ILI病原谱以流感病毒、人鼻病毒、支原体和副流感病毒为主,部分病毒呈现年龄段偏好性和季节性的流行特点.

Two influenza B virus lineages, B/Victoria and B/Yamagata, are co-circulating in human population. While the two lineages are serologically distinct and TIV only contain one lineage. It is important to investigate the epidemiological and evolutionary dynamics of two influenza B virus lineages in Beijing after the free influenza vaccine policy from 2007. Here, we collected the nasopharyngeal swabs of 12657 outpatients of influenza-like illness and subtyped by real-time RT-PCR during 2011-2017. The HA and NA genes of influenza B were fully sequenced. The prevalence is the highest in the 6-17 years old group among people infected with influenza B. Yamagata-lineage virus evolved to two inter-clade from 2011-2014 to 2014-2017. The amino acids substitutions of HA1 region were R279K in strains of 2011-2014 and L173Q, M252V in strains of 2014-2017. Substitutions L58P, I146V were observed in HA1 region of Victoria-lineage virus in 2011-2012 and I117V, N129D were showed in 2015-2017. Phylogenetic analysis of NA showed Yamagata-Victoria inter-lineage reassortant occurred in 2013-2014. Influenza B mainly infect the school-aged children in Beijing and the free influenza vaccine inoculation does not seem to block school-age children from infection with influenza B. The antigen characteristics of circulating influenza B were different to the recommended vaccine strains. We concluded that the Victoria-lineage vaccine strain should been changed and the free influenza vaccine should be revalued.

目的 了解2013年北京市朝阳区柯萨奇A6型(Coxsackievirus A6,CVA6)病毒的流行特点及其基因特征.方法 对2013年收集的795份手足口病患者的咽拭子样本进行肠道病毒检测,对非EV71、非CVA16型病毒阳性样本进行CVA6荧光定量PCR检测,选取CVA6阳性样本进行VP1片段(794bp)序列扩增与测序,运用Clustalx软件和MEGA4.0软件对本地区CVA6的VP1片段序列与从NCBI下载的CVA6的VP1参考序列进行聚类分析.结果 肠道病毒通用型核酸阳性样本共计382例(48.1％,382/795),其中非EV71、非CVA16型病毒236例(61.8％,236/382);非EV71、非CVA16型病毒阳性样本中有CVA6型病毒样本185例(78.4％,185/236).基于VP1片段的聚类分析,结果显示2013年该地区的CVA6型病毒与中国地区的参考序列明显聚为一类;CVA6在系统进化树中形成A、B和C等3个基因型,C基因型又可分为C1和C2两个基因亚型;两个基因亚型间的核苷酸序列差异度为10.8％ ～ 13.2％.朝阳区所有的CVA6都位于C基因型,C1亚型包括了大部分该地区序列.结论 2013年该地区的CVA6已经超过了EV71和CVA16,首次成为北京市朝阳区手足口病的主要病原体.该地区存在CVA6的C1和C2两个基因亚型的共循环,其中C1亚型对该地区2013年CVA6的暴发流行起关键作用.

Objective To explore the pathogenic spectrum and predominant type of non-EV71, non-CoxA16 enteroviruses caused hand, foot and mouth disease(HFMD) in Chaosyang, Beijing in 2012. Methods The 815 specimens were collected from outpatient and in-patient cases of HFMD. The specimens which were non-EV71, non-CoxA16 enteroviruses were identified by real-time PCR. The genotyping of non-EV71, non-CoxA16 enteroviruses was performed by PCR and sequencing of 5'UTR and VP2 sequences.The sequence and phylogenetic analysis of the VP2 genes was performed. Results 61 specimens were identified as non-EV71, non-CoxA16 enterovirus positive by real-time PCR. And the types of the non-EV71, non-CoxA16 enterovirus were identified by sequence BLAST: 44 CoxA10(73.3%, 44/60), 8 CoxA6(13.3%, 8/60) and 1 CoxA4(1.7%, 1/60). 1 out of 61 specimens was tested as EV71 and 7 specimens were failed to typing. The CoxA10, CoxA6 and CoxA4 enterovirus in this study had high homology with those isolated in China, while lower homology with their prototype viruses described in the NCBI database. Phylogenetic analysis showed that there were two lineages of CoxA6 co-circulating in Chaoyang. Conclusion Hand, foot and mouth disease in Chaoyang, Beijing is concerned with diverse non-EV71, non-CoxA16 enteroviruses, including CoxA10, CoxA6 and CoxA4. And CoxAl0 is the predominant type among non-EV71, non-CoxAl6 enteroviruses.