STUDY OF T－LYMPHOCYTE SUBSETS AND INTERLEUKIN－2 AND INTERLEUKIN－2 RECEPTOR OF RESPIRATORY SYNCYTIAL VIRUS PNEUMONIA

T-Lymphocyte subsets and humoral immune and the activity of IL-2 and IL-2R in respiratory syncytial virus (RSV) pneumonia in 26 cases were tested. The result showed in the patients with RSV pneumonia the averages of T3 and T4 were 37.56±1.46% and 27. 15±8. 02% respectively,They were significantly lower than 53.4 ±9.2% and 35.5±7.7% of averages of T3 and T4 in healthy controlled group (both. P< 0. 001 ), the average of T3 was 22. 73±7.06%, it was lower an 26. 7±6. 3 % of T8 in controlled group (P<0. 02 );the ratio of T4/T8 was 1. 245±0. 399 ,there was no significant difference from 1. 35 ±0. 17 of the ratio in controlled group (P > 0. 1). The mean value of IgG was 1. 177± 0. 3685g/L, it was significantly lower than 1. 427± 0. 498g/L of that in controlled group(P < 0. 005). The mean values of IgA and IgM were 0. 1136±0.0393g/L and 0. 768±0. 353g/L respectively, they were significantly lower than 0. 2706 ±0. 876g/L and 0. 122±0. 061g/L of IgA and IgM in controlled group. The activity of IL-2 and IL-2R were 17. 46 ±5. 79%, and 28. 32 ±5. 924% respectively, they were significantly lower than 30. 22 ±14. 55% and 39. 53±8. 61 % of those in healthy group (both P < 0. 001). The severe the pneuumonia, the greater the lowering of IL-2 and IL-2R. These about results suggested that RSV could greatly suppress the immune function of the patients, inducing secondary immunodeficiency, leading to repeated breather and asthma.

Qingfei oral liquid downregulates TRPV1 expression to reduce airway inflammation and mucus hypersecretion injury caused by respiratory syncytial virus infection and asthma in mice

Objective:Qingfei oral liquid(QF),an experimental Chinese medicine prescription developed from the ancient priscription of traditional Chinese medicines Ma Xin Shi Gan decoction and Tingli Dazao Xie Fei decoction,has been effectively used since decades to treat patients with viral pneumonia and asthma.In our previous study,we had demonstrated that QF can significantly reduce airway hyperresponsiveness,hyperemia,lung tissue edema,inflammatory lung tissue infiltration in mice,airway mucus secretion,and peripheral airway collagen hyperplasia;however,its mechanism of action is unknown.Methods:Fifty 6–8-week-old male BALB/c mice were equally and randomly divided into five groups:the control,ovalbumin(OVA),OVA+respiratory syncytial virus(RSV),QF,and dexamethasone(Dxms)groups.The QF group was administered QF at 1.17 g·kg−1·d−1,the Dxms group received dexamethasone injections at 0.2 mg·kg−1·d−1,and the remaining groups were administered PBS.Inflammation in the lung tissue was assessed by hematoxylin and eosin(HE),periodic acid–Schiff(PAS),and Van Gieson staining.ELISA was used to evaluate the IL-13,IL-25,and IL-33 in the mice.Western blotting was used to examine changes in the proteins levels of transient receptor potential vanilloid-1(TRPV1)and mucin 5AC(MUC5AC)in the lung tissues of mice.Results:Histopathological evaluation revealed that the OVA and OVA+RSV groups exhibited lung tissue edema and inflammatory lung tissue infiltration in the HE staining and airway secretions in the PAS staining;collagen hyperplasia around the airway was increased in these two groups compared with the control group.The QF group exhibited significantly reduced lung tissue edema,inflammatory lung tissue infiltration,airway secretions,and collagen hyperplasia around the airway compared with the OVA+RSV group.We analyzed the serum levels of IL-13,IL-25,and IL-33 in the mice and found that these levels were higher in the OVA and OVA+RSV groups than in the control group(P<0.05 in the OVA group,P<0.01 in the OVA+RSV group).The QF group exhibited significantly decreased serum levels of IL-13,IL-25,and IL-33 compared with the OVA+RSV group(all P<0.05).The Dxms group also exhibited significant decreases in the serum levels of IL-13 and IL-33(all P<0.05)but no significant decrease in the serum levels of IL-25 compared with the RSV+OVA group.Finally,we examined the protein levels of TRPV1 and MUC5AC in the lung tissues of mice using Western blotting.After identifying RSV infection in the mice with asthma,the protein levels of TRPV1 and MUC5AC in the lung tissues of mice were significantly higher than those in the control group(P<0.05,P<0.01).We found that compared with RSV+OVA,QF can significantly downregulate the protein level of TRPV1;further,the protein level of MUC5AC was also significantly reduced(all P<0.001).Conclusion:QF can inhibit RSV replication and reduce airway inflammation and mucus hypersecretion injury caused by RSV infection and asthma,and its mechanism of action may be associated with the downregulation of TRPV1 expression and a decrease in airway mucus hypersecretion injury.

The Association of Respiratory Syncytial Virus Infection and Childhood Asthma: A Meta-Analysis

Objective: To explore the close relationship between respiratory syncytial virus (RSV) infection and acute attack of childhood asthma. Methods: A computer-based search of database from Pumbed, CNKI, Wanfang, Baidu Scholar, Chongqing VIP, GeenMedica was performed to screen the articles about respiratory syncytial virus infection and childhood asthma. Then the literatures were screened out by the selection criteria. The RevMan5.3 software was used to test the heterogeneity and effect values of each study, analyze the sensitivity and publication bias of the literature, and draw on Meta forest plot and Funnel plot. Results: 5 articles conformed to the selection criteria. There were totally 881 cases in the case group, 826 cases in the control group. The results of heterogeneity test showed no heterogeneity between each study (P > 0.05). The fixed-effects model showed the 6.68 (5.06 - 8.82), (Z = 13.38, P < 0.00001). Conclusion: The infection rate of respiratory syncytial virus in children with acute asthma attack is higher than that in remission period. Respiratory syncytial virus infection rate can be used as an indicator of the severity of asthma in children.

Use of flow cytometry to investigate the cytokine response pattern in infants with respiratory syncytial virus infection and bronchiolitis

Objective: To investigate the cytokine response pattern (IL 4/IFN γ ) in infants with RSV infections and bronchiolitis during the acute phase. Methods: Four color flow cytometry was used to measure intracellular IL 4 and IFN γ expressions in peripheral blood CD3+ and CD8+ lymphocytes from RSV infected and bronchiolitis infants. Serum IL 4 and IFN γ levels were also determined. Results: RSV infected and bronchiolitis infants showed no statistical differences from not RSV infected or pneumonia infants and control in the frequency of IL 4 and IFN γ expressions in CD3+CD8 lymphocytes, showed no obvious Th1/Th2 imbalance, while IFN γ was expressed much more frequently in CD3+CD8+ lymphocytes. Systematically, RSV infected and bronchiolitis infants showed much lower levels of serum IL 4 and IL 4/IFN γ ratios and much higher serum IFN γ levels than control. However, there were no statistical differences in the above three indices between RSV infected and not RSV infected infants or between bronchiolitis and pneumonia infants, except that bronchiolitis infants had a higher level of serum IFN γ than pneumonia infants statistically. Conclusions: There is no type 2 cytokine response predominance in the acute phase of RSV infection and bronchiolitis. IL 4 production is suppressed and IFN γ production upregulated, the latter being most prominent in bronchiolitis infants.

A multi-center study on genetic variations in the fusion protein of respiratory syncytial virus from children with Acute Lower Respiratory Tract Infections in China during 2017-2021

Respiratory syncytial virus(RSV)is a significant cause of acute lower respiratory tract infection(ALRTI)in children underfive years of age.Between 2017 and 2021,396 complete sequences of the RSV F gene were obtained from 500 RSV-positive throat swabs collected from ten hospitals across nine provinces in China.In addition,151 sequences from China were sourced from GenBank and GISAID,making a total of 549 RSV F gene sequences subjected to analysis.Phylogenetic and genetic diversity analyses revealed that the RSV F genes circulating in China from 2017 to 2021 have remained relatively conserved,although some amino acids(AAs)have undergone changes.AA mutations with frequencies10%were identified at six sites and the p27 region:V384I(site I),N276S(site II),R213S(siteØ),and K124N(p27)for RSV A;F45L(site I),M152I/L172Q/S173 L/I185V/K191R(site V),and R202Q/I206M/Q209R(siteØ)for RSV B.Comparing mutational frequencies in RSV-F before and after 2020 revealed minor changes for RSV A,while the K191R,I206M,and Q209R frequencies increased by over 10%in RSV B.Notably,the nirsevimab-resistant mutation,S211N in RSV B,increased in frequency from 0%to 1.15%.Both representative strains aligned with the predicted RSV-F structures of their respective prototypes exhibited similar conformations,with low root-mean-square deviation values.These results could provide foundational data from China for the development of RSV mAbs and vaccines.

Qingkailing Injection(清开灵注射液)for Treatment of Children Pneumonia Induced by Respiratory Syncytial Virus:A Meta-Analysis of Rando mized Controlled Trials

Objective： To evaluate the efficacy and safety of Qingkailing Injection（清开灵注射液, QKL） for treatment of children pneumonia caused by respiratory syncytial virus（RSV）. Methods： Randomized clinical trials（RCTs） comparing QKL with ribavirin injection in the treatment of children pneumonia induced by RSV were searched in Pub Med, Science Direct, Cochrane Library, Chinese VIP database, CNKI and Wanfang databases from their inception to March 2014. Meta-analyses were performed using RevMan 5.2 software. The methodological quality of the selected RCTs was evaluated by the Modified Jadad Score. The primary outcome measures were effective rate and the secondary outcomes were relief time of fever and cough. Results： Seven RCTs with 992 cases published from 2008 to 2013 were identified. The meta-analysis results indicated that QKL was more effective in cure rate [risk ratios（RR）=1.32, 95% CI（1.17, 1.50）, P〈0.01], total effective rate [RR=1.07, 95% CI（1.02, 1.13）, P=0.009] and less fever clearance time [mean difference=–0.73, 95% CI（–1.22, –0.23）, P=0.004], compared with ribavirin injection in the treatment of RSV-induced children pneumonia. No dead case was reported in all trials. There were 3 trials mentioned adverse events, 2 reported no obvious adverse event occurred while 1 reported adverse events described as skin hypersensitivity, elevation of ALT, a mild abnormal of hepatic and renal function in both QKL and ribavirin group. Conclusions： QKL was an effective and relatively safe option for the treatment of RSV-induced children pneumonia. These therapeutic effects were promising but need to be interpreted with caution due to variations in the treatment and methodological weakness in the studies.

Characteristics of respiratory syncytial virus-induced bronchiolitis co-infection with Mycoplasma pneumoniae and add-on therapy with montelukast

Background:The influence of Mycoplasma pneumoniae(MP)infection on bronchiolitis remains unclear.Additionally,reports on the efficacies of leukotriene receptor antagonists in the treatment of bronchiolitis have been inconclusive.Methods:Children with respiratory syncytial virus(RSV)-induced bronchiolitis were divided into two groups:RSV+MP group and RSV group.Each group was randomly divided into two subgroups:one received routine and placebo treatment,while the other received routine and montelukast treatment for 9 months.The cumulative numbers of wheezing episodes and recurrent respiratory tract infections were recorded.Blood parameters were determined.Results:Patients in the RSV+MP group exhibited an older average age,fever,more frequent flaky and patchy shadows in chest X-rays,more frequent extrapulmonary manifestations,and longer hospital stays compared with patients in the RSV group.Additionally,higher baseline blood eosinophil counts,eosinophil cationic protein(ECP),total immunoglobulin E(IgE),interleukin(IL)-4,IL-5,IL-4/interferon-γratios,leukotriene(LT)B4,and LTC4,and lower baseline lipoxin A4(LXA4)/LTB4 ratios were observed in the RSV+MP group compared with the RSV group.Montelukast treatment decreased the cumulative numbers of recurrent wheezing episodes and recurrent respiratory tract infections at 9 and 12 months.This efficacy may be related to the montelukast-induced reductions in peripheral eosinophil counts,ECP and total IgE,as well as the montelukast-dependent recovery in T helper(Th)1/Th2 balance and LXA4/LTB4 ratios in children with bronchiolitis.Conclusions:RSV bronchiolitis with MP infection was associated with clinical and laboratory features that differed from those of RSV bronchiolitis without MP infection.Add-on therapy with montelukast for 9 months was benefi cial for children with bronchiolitis at 9 and 12 months after the initiation of treatment.

A multi-center study on Molecular Epidemiology of Human Respiratory Syncytial Virus from Children with Acute Lower Respiratory Tract Infections in the Mainland of China between 2015 and 2019

Human respiratory syncytial virus(RSV) is a major pathogen of acute lower respiratory tract infection among young children. To investigate the prevalence and genetic characteristics of RSV in China, we performed a molecular epidemiological study during 2015–2019. A total of 964 RSV-positive specimens were identified from 5529 enrolled patients during a multi-center study. RSV subgroup A(RSV-A) was the predominant subgroup during this research period except in2016. Totally, 535 sequences of the second hypervariable region(HVR-2) of the G gene were obtained. Combined with182 Chinese sequences from GenBank, phylogenetic trees showed that 521 RSV-A sequences fell in genotypes ON1(512),NA1(6) and GA5(3), respectively;while 196 RSV-B sequences fell in BA9(193) and SAB4(3). ON1 and BA9 were the only genotypes after December 2015. Genotypes ON1 and BA9 can be separated into 10 and 7 lineages, respectively. The HVR-2 of genotype ON1 had six amino acid changes with a frequency more than 10%, while two substitutions H258 Q and H266 L were co-occurrences. The HVR-2 of genotype BA9 had nine amino acid substitutions with a frequency more than10%, while the sequences with T290 I and T312 I were all from 2018 to 2019. One N-glycosylation site at 237 was identified among ON1 sequences, while two N-glycosylation sites(296 and 310) were identified in the 60-nucleotide duplication region of BA9. To conclusion, ON1 and BA9 were the predominant genotypes in China during 2015–2019. For the genotypes ON1 and BA9, the G gene exhibited relatively high diversity and evolved continuously.

A respiratory syncytial virus persistent-infected cell line system reveals the involvement of SOCS1 in the innate antiviral response

HEp-2 cells persistently infected with respiratory syncytial virus(RSV) are a heterogeneous mixture of viral antigen-positive and-negative variants; however, the mechanism through which viral replication becomes latent remains unclear. In this study, we investigated the potential mechanism by which RSV escapes from innate immune surveillance. Persistent-infected RSV HEp-2 cells were isolated and cell clones were passaged. The RSV-persistent cells produced viruses at a lower titer, resisted wild-type RSV re-infection, and secreted high levels of interferon-β(IFN-β), macrophage inflammatory protein-1α(Mip-1α), interleukin-8(IL-8), and Rantes. Toll-like receptor 3(TLR3), retinoic acid inducible gene-I(RIG-I), and suppressor of cytokine signaling 1(SOCS1) levels were upregulated in these cells. The silencing of TLR3 m RNA decreased the expression of SOCS1 protein and the secretion of cytokines. RSV-persistent cells are in an inflammatory state; upregulation of SOCS1 is related to the TLR3 signaling pathway, which could be associated with the mechanism of viral persistence.

The preventive effect of vaccine prophylaxis on severe respiratory syncytial virus infection:A meta-analysis

Respiratory syncytial virus(RSV) is the key underlying cause of acute lower respiratory tract infection in infants; however, no licensed vaccine against RSV infection is currently available. This study was undertaken to assess the preventive effect of vaccine on RSV infection. In this metaanalysis, 1,792 published randomized clinical trials of RSV vaccines from Jan 1973 to Sep 2015 were examined. Among thirteen studies that met the inclusion criteria, eleven studies estimated the impact of RSV vaccines and four studies estimated the effect of adjuvants. The odds ratios(ORs) were 0.31(95% CI, 0.15–0.67) and 0.62(95% CI, 0.29–1.34), respectively. We found that RSV subunit vaccines can significantly reduce the incidence of RSV infection and that whether vaccination with adjuvant therapy was an effective strategy still remained to be studied. This analysis of the preventive effect of vaccines on RSV infection has direct applications for the prevention of RSV infections.

Evaluation of the Safety and Immune Efficacy of Recombinant Human Respiratory Syncytial Virus Strain Long Live Attenuated Vaccine Candidates

Human respiratory syncytial virus(RSV)infection is the leading cause of lower respiratory tract illness(LRTI),and no vaccine against LRTI has proven to be safe and effective in infants.Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice.The constructed recombinant plasmids harbored(5′to 3′)a T7 promoter,hammerhead ribozyme,RSV Long strain antigenomic cDNA with cold-passaged(cp)mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain(A2cpts)or further combined with SH gene deletion(A2cptsΔSH),HDV ribozyme(δ),and a T7 terminator.These vectors were subsequently co-transfected with four helper plasmids encoding N,P,L,and M2-1 viral proteins into BHK/T7-9 cells,and the recovered viruses were then passaged in Vero cells.The rescued recombinant RSVs(rRSVs)were named rRSV-Long/A2cp,rRSV-Long/A2cpts,and rRSV-Long/A2cptsΔSH,respectively,and stably passaged in vitro,without reversion to wild type(wt)at sites containing introduced mutations or deletion.Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed temperature-sensitive(ts)phenotype in vitro and in vivo,all rRSVs were significantly attenuated in vivo.Furthermore,BALB/c mice immunized with rRSVs produced Th1-biased immune response,resisted wtRSV infection,and were free from enhanced respiratory disease.We showed that the combination ofΔSH with attenuation(att)mutations of cpts contributed to improving att phenotype,efficacy,and gene stability of rRSV.By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains,we have laid an important foundation for the development of RSV live attenuated vaccines.

Label-free quantitative proteomics reveals fibrinopeptide B and heparin cofactorⅡas potential serum biomarkers in respiratory syncytial virus-infected mice treated with Qingfei oral liquid formula

Respiratory syncytial virus(RSV) is a leading cause of acute lower respiratory tract infections. Qingfei oral liquid(QFOL), a traditional Chinese medicine, is widely used in clinical treatment for RSV-induced pneumonia. The present study was designed to reveal the potential targets and mechanism of action for QFOL by exploring its influence on the host cellular network following RSV infection. We investigated the serum proteomic changes and potential biomarkers in an RSV-infected mouse pneumonia model treated with QFOL. Eighteen BALB/c mice were randomly divided into three groups: RSV pneumonia model group(M), QFOL-treated group(Q) and the control group(C). Serum proteomes were analyzed and compared using a label-free quantitative LC-MS/MS approach. A total of 172 protein groups, 1009 proteins, and 1073 unique peptides were successfully identified. 51 differentially expressed proteins(DEPs) were identified(15 DEPs when M/C and 43 DEPs when Q/M; 7 DEPs in common). Classification and interaction network showed that these proteins participated in various biological processes including immune response, blood coagulation, complement activation, and so forth. Particularly, fibrinopeptide B(FpB) and heparin cofactor Ⅱ(HCII) were evaluated as important nodes in the interaction network, which was closely involved in coagulation and inflammation. Further, the Fp B level was increased in Group M but decreased in Group Q, while the HCII level exhibited the opposite trend. These findings not only indicated FpB and HCII as potential biomarkers and targets of QFOL in the treatment of RSV pneumonia, but also suggested a regulatory role of QFOL in the RSV-induced disturbance of coagulation and inflammation-coagulation interactions.

Dynamic Host Immune and Transcriptomic Responses to Respiratory Syncytial Virus Infection in a Vaccination-Challenge Mouse Model

Respiratory syncytial virus(RSV) is the major cause of lower respiratory tract infections in children. Inactivated RSV vaccine was developed in the late 1960’s, but the vaccine-enhanced disease(VED) occurred to vaccinated infants upon subsequent natural RSV infection. The excessive inflammatory immunopathology in the lungs might be involved in the VED, but the underlying mechanisms remain not fully understood. In this study, we utilized UV-inactivated RSV in the prime/boost approach followed by RSV challenge in BALB/c mice to mimic RSV VED. The dynamic virus load,cytokines, histology and transcriptome profiles in lung tissues of mice were investigated from day 1 to day 6 post-infection.Compared to PBS-treated mice, UV-RSV vaccination leads to a Th2 type inflammatory response characterized by enhanced histopathology, reduced Treg cells and increased IL4^(+)CD4 T cells in the lung. Enhanced production of several Th2 type cytokines(IL-4, IL-5, IL-10) and TGF-b, reduction of IL-6 and IL-17 were observed in UV-RSV vaccinated mice. A total of 5582 differentially expressed(DE) genes between PBS-treated or vaccinated mice and na?ve mice were identified by RNA-Seq. Eleven conserved high-influential modules(HMs) were recognized, majorly grouped into regulatory networks related to cell cycle and cell metabolism, signal transduction, immune and inflammatory responses. At an early time post-infection, the vaccinated mice showed obvious decreased expression patterns of DE genes in 11 HMs compared to PBS-treated mice. The extracellular matrix(HM5) and immune responses(HM8) revealed tremendous differences in expression and regulation characteristics of transcripts between PBS-treated and vaccinated mice at both early and late time points. The highly connected genes in HM5 and HM8 networks were further validated by RT-qPCR.These findings reveal the relationship between RSV VED and immune responses, which could benefit the development of novel RSV vaccines.

IL-33在呼吸道合胞病毒(RSV)感染致哮喘急性发作中的作用

目的研究IL-33在呼吸道合胞病毒(respiratory syncytial virus,RSV)感染致哮喘急性发作中的作用。方法将24只3周龄SPF级BALB/c雌性小鼠随机分为PBS组、RSV组、卵清白蛋白(ovalbumin,OVA)组和OVA/RSV组,每组6只。首先应用OVA或PBS激发并致敏小鼠,再感染RSV致哮喘急性发作。麻醉后处死小鼠。ELISA法测小鼠血清总IgE水平、支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)及肺组织IL-33蛋白水平;瑞氏/吉姆萨染色后测BALF细胞总数及各细胞分类计数;取肺组织病理切片HE染色;real-time PCR测T辅助细胞2型(T helper 2,Th2)细胞因子、IL-33等mRNA表达。结果 OVA组与PBS组相比,血清IgE水平明显升高(P<0.05)。OVA/RSV组中BALF细胞总数较OVA组显著增加,主要表现为巨噬细胞和中性粒细胞的增加。病理切片HE染色可见OVA/RSV组小气道周围炎性细胞浸润更加明显。以上表明RSV感染OVA诱导哮喘急性发作的小鼠模型成功建立。real-time PCR显示:与OVA组相比,OVA/RSV组IL-13以及IL-33 mRNA表达显著增加(P<0.05),IL-5和ST2表达有所增加,但差异无统计学意义。ELISA结果显示:与OVA组相比,OVA/RSV组肺组织中IL-33浓度增高更加显著(P<0.05),BALF中IL-33浓度也有所增加,但差异无统计学意义。结论 IL-33可能通过启动Th2型免疫反应在RSV感染诱导哮喘急性发作小鼠模型中起重要作用。

3种治法对RSV诱导的肺炎小鼠炎性细胞因子的表达及TLR-4/NF-кB信号通路调控研究

目的:探讨3种治法代表方剂对呼吸道合胞病毒(RSV)诱导引起肺炎的小鼠血清IL-6、IL-8及肺组织Toll样受体4(TLR4)、细胞核转录因子(NF-кB)的影响,揭示其治疗机制。方法:将Wister小鼠随机分为正常组、模型组、利巴韦林组、银翘散组、玉屏风散组、银屏散组。于感染前3 d,玉屏风散组、银屏散组连续给予玉屏风散(7.5 g·kg·d-1)3 d;除正常组以外,50μL 10 LD50病毒液滴鼻建立呼吸道合胞病毒感染的小鼠RSV肺炎模型。感染2 h后,银翘散组、银屏散组继续给予银翘散治疗(10 g·kg·d-1),连续给药3 d;采用ELISA法检测各组小鼠血清中IL-6、IL-8含量,免疫组化法检测分析肺组织TLR4、NF-кB P65蛋白的表达。结果:与正常组比较,RSV感染诱导小鼠肺组织中TLR4蛋白表达上调,增加NF-кB的活化(P<0.05),使血清中IL-6、IL-8水平升高(P<0.05)。银翘散组、玉屏风散组、双表法组测得IL-6、IL-8含量以及TLR4、NF-κB P65表达相较于模型组显著减弱(P<0.05)。与利巴韦林组比较,双表法组减弱尤为突出(P<0.05)。结论:3种治法对于治疗RSV肺炎均有显著疗效,尤其以双表法疗效更佳。其作用机制可能与抑制炎症因子IL-6、IL-8分泌及阻断TLR4/NF-κB信号通路有关。

丙种球蛋白治疗RSV毛细支气管炎的临床及免疫学研究

为评估静脉注射丙种球蛋白(IVIG)治疗呼吸道合胞病毒毛细支气管炎(RSV毛支)的临床疗效及免疫学机理,比较26例IVIG治疗组和30例常规治疗组患儿症状体征消失时间及住院天数,同时检测治疗前后血清白介素6(IL-6)、白介素8(IL-8)及肿瘤坏死因子-α(TNF-α)水平。结果:与常规治疗组相比,IVIG治疗组喘憋和肺部体征消失时间明显缩短(4.0天±1.1天比5.2天±1.4天,5.4天±1.5天比6.5天±1.8天,P分别<0.001和<0.05),而住院天数则无显著差异(9.0天±2.2天比10.3天±3.1天,P>0.05)。治疗前两组患儿血清IL-6、IL-8及TNF-α水平均高于正常对照组;IVIG治疗后3种细胞因子水平明显降低.但与常规治疗组相比无显著差异。结论:细胞因子参与了RSV毛支的发病过程。IVIG治疗有较确切的临床疗效,但单剂(0.25g/kg)对血清细胞因子的抑制作用不明显。

Prevalence,variation,and transmission patterns of human respiratory syncytial virus from pediatric patients in Hubei,China during 2020–2021

Human respiratory syncytial virus(RSV)is a severe threat to children and a main cause of acute lower respiratory tract infections.Nevertheless,the intra-host evolution and inter-regional diffusion of RSV are little known.In this study,we performed a systematic surveillance in hospitalized children in Hubei during 2020–2021,in which 106 RSV-positive samples were detected both clinically and by metagenomic next generation sequencing(mNGS).RSV-A and RSV-B groups co-circulated during surveillance with RSV-B being predominant.About 46 high-quality genomes were used for further analyses.A total of 163 intra-host nucleotide variation(iSNV)sites distributed in 34 samples were detected,and glycoprotein(G)gene was the most enriched gene for iSNVs,with non-synonymous substitutions more than synonymous substitutions.Evolutionary dynamic analysis showed that the evolutionary rates of G and NS2 genes were higher,and the population size of RSV groups changed over time.We also found evidences of inter-regional diffusion from Europe and Oceania to Hubei for RSV-A and RSV-B,respectively.This study highlighted the intra-host and inter-host evolution of RSV,and provided some evi-dences for understanding the evolution of RSV.

沈阳地区婴幼儿RSV感染的病原学调查研究

查明冬春季沈阳地区婴幼儿RSV感染流行情况。采用APAAP法和IFA法对 6 5例临床诊断为急性病毒性下呼吸道感染的婴幼儿进行了检查。在RSV感染的高发季节由RSV引起婴幼儿的急性下呼吸道感染的阳性率为 44 .6 0 % (2 9/ 6 5 ) ,0～ 6个月婴幼儿感染率最高 ,为 74.0 7% (2 0 / 2 7) ,并有明显的喘息倾向。以上结果表明RSV仍是引起婴幼儿急性下呼吸道感染 ,特别是肺炎和毛细支气管炎的重要病原体 ,沈阳地区仍有流行。为防止和控制RSV的流行及为RSV的防治提供了依据。

IL-23、IL-27对RSV重组蛋白疫苗免疫原性的影响

目的:以编码IL-23和IL-27的真核表达质粒pcDNA3.1-IL-23(以下简称IL-23)和pcDNA3.1-IL-27(以下简称IL-27)为佐剂,与呼吸道合胞病毒(RSV)重组蛋白疫苗G1F/M2共免疫小鼠,观察IL-23和IL-27对疫苗的免疫原性的影响。方法:以IL-23、IL-27质粒和Al(OH)3为免疫佐剂,与G1F/M2共免疫BALB/c小鼠,末次免疫后10天杀死小鼠,用ELISA检测特异性IgG、IgG1和IgG2a水平;流式细胞术检测小鼠脾细胞CD4+、CD8+细胞的变化;用乳酸脱氢酶(LDH)释放法检测特异性小鼠脾细胞杀伤活性。结果:G1F/M2+Al(OH)3+IL-23和G1F/M2+Al(OH)3+IL-27可诱导高效价的IgG、IgG1、IgG2a抗体,且显著高于这三种佐剂单独使用诱导的抗体效价;流式细胞检测结果显示G1F/M2+IL-23和G1F/M2+Al(OH)3+IL-23刺激的CD4+T细胞和CD8+T细胞水平显著高于其他组;单独的IL-23或IL-27对G1F/M2诱导的脾细胞杀伤活性没有增强作用,而Al(OH)3+IL-23和Al(OH)3+IL-27佐剂组的杀伤率显著高于单独的IL-23、IL-27或Al(OH)3组。结论:这些结果表明:IL-23或IL-27质粒与传统铝盐佐剂Al(OH)3联合使用能显著增强RSV重组疫苗G1F/M2的免疫原性。

A protective human antibody against respiratory syncytial virus by targeting a prefusion epitope across sites IV and V of the viral fusion glycoprotein

Respiratory syncytial virus(RSV)is one of the leading pathogens that cause lower respiratory tract infections in infants and the elderly.Passive immunoprophylaxis with monoclonal antibody(mAb)has been approved to prevent morbidity and mortality from RSV infection in infants.Here we report the isolation of two neutralizing mAbs against RSV from convalescent children by prefusion form of fusion(F)glycoprotein as bait.One mAb RV11 exhibited good potency in neutralization of RSV strains from both A and B subtypes in cell-based assay,and protected mice from RSV infection in vivo.An RV11 escape mutant was identified,which contains an S443P mutation in F protein.Crystal structure showed the RV11 bound to a conserved prefusion epitope across the antigenic sites IV and V of the F glycoprotein.RV11 showed a strong synergistic effect when combined with two RSV antivirals,an F-targeting small molecular inhibitor ziresovir and a siteØneutralizing mAb D25(the parental mAb for nirsevimab).The study extended our knowledge to the neutralizing and protective epitopes of RSV,and the mAb RV11 deserves further development for clinical translation.