RELATIONSHIP BETWEEN HYPERSENSITIVITY TYPE I AND WHEEZING BY RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION

We studied the RSV specific IgE antibody, histamine and basophil from infants with RSV bronchiolitis and found during the acute phase either the titers of RSV-IgE or the concentration of histamine increased significantly, the number of basophil and basophil degranulation in the presence of RSV antigen also increased. In vitro studies revealed hypersensitivity participates in the pathogenesis of RSV bronchiolitis. We also found that infants with RSV bronchiolitis, the RSV-IgE persisted for a long time presumably this plays an important role in recurrent wheezing after RSV infection for years.

Antiviral Effect of Emodin from Rheum palmatum against Coxsakievirus B_5 and Human Respiratory Syncytial Virus In Vitro

Summary： Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus （CV） and respira- tory syncytial virus （RSV）. However, no antiviral agents with low toxicity and drug resistance are cur- rently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin （an ingredient of Rheum palmatum） against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum pal- matum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication in- hibition, virucidal and anti-absorption effects, by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tet- razolium bromide （MTT） assay and plaque reduction assay （PRA）. The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR （qPCR）. Cytokine （IFN-γ, TNF-α） mRNA expressions after emodin treatment （7.5, 15, 30 μmol/L） were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration （EC50） ranging from 13.06 to 14.27 μmol/L and selectivity index （SI） being 5.38-6.41 μmol/L. However, emodin couldn＇t directly inacti- vate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB4 and RSV in a concentration- and time-dependent manner, especially during the first 0-4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

Burden of respiratory syncytial virus infection in young children

Respiratory syncytial virus(RSV) is the most frequent and important cause of lower respiratory tract infection in infants and children. It is a seasonal virus, with peak rates of infection occurring annually in the cold season in temperate climates, and in the rainy season, as temperatures fall, in tropical climates. High risk groups for severe RSV disease include infants below six mo of age, premature infants with or without chronic lung disease, infants with hemodynamically significant congenital heart disease, infants with immunodeficiency or cystic fibrosis, and infants with neuromuscular diseases. Mortality rates associated with RSV infection are generally low in previous healthy infants(below 1%), but increase significantly in children with underlying chronic conditions and comorbidities. Following early RSV lower respiratory tract infection, some patients experience recurrent episodes of wheezing mimicking early childhood asthma with persistence of lung function abnormalities until adolescence. There is currently no RSV vaccine available, but promising candidate vaccines are in development. Palivizumab, a monoclonal RSV antibody that is the only tool for immunoprophylaxis in high-riskinfants, lowers the burden of RSV infection in certain carefully selected patient groups.

Human Milk Oligosaccharides Enhance Innate Immunity to Respiratory Syncytial Virus and Influenza <i>in Vitro</i>

Human milk oligosaccharides (HMO) contribute to innate immunity by enhancing growth of beneficial bacteria, epithelial cell maturation and mucosal barrier integrity. They have immunomodulatory effects and can block pathogen binding to host cell surface glycans or receptors. We investigated the effects of 2’-fucosyllactose (2’FL), 6’-sialyllactose (6’SL), 3’-sialyllactose (3’SL) and lacto-N-neoTetraose (LNnT) on human respiratory epithelial cell lines or peripheral blood mononuclear cells (PBMCs) following respiratory viral infectionin vitro. Expression of cytokines and viral load were monitored in infected cells. These biomarkers of innate immunity were selected since viral load and cytokine levels (IP-10, MIP-1α, IL-6, IL-8, TNF-α) have been correlated with disease severity in respiratory syncytial virus (RSV) and influenza (IAV) virus infectionin vivo. 2’FL significantly decreased RSV viral load and cytokines associated with disease severity (IL-6, IL-8, MIP-1α) and inflammation (TNF-α, MCP-1) in airway epithelial cells. LNnT and 6’SL significantly decreased IAV viral load in airway epithelial cells. 6’SL dose-dependently down-regulated IP-10 and TNF-α in RSV infected PBMCs. HMO at or below levels found in breast milk enhance innate immunity to respiratory viruses in vitro and may interact directly with cells to modulate biomarkers of innate immunity.

Prevalence of respiratory syncytial virus infection among children hospitalized with acute lower respiratory tract infections in Southern India

BACKGROUND Respiratory syncytial virus(RSV) is a leading cause of lower respiratory infections among children.AIM To investigate the proportion of RSV and non-RSV respiratory viral infections among hospitalized children ≤ 5 years.METHODS Hospitalized children aged < 5 years, with a diagnosis of acute lower respiratory infections(ALRI), admitted between August 2011-August 2013, were included.Cases were defined as laboratory-confirmed RSV and non-RSV respiratory viruses by direct fluorescence assay from the nasopharyngeal wash.RESULTS Of 383 1-59 mo old children hospitalized with an acute lower respiratory infection, 33.9%(130/383) had evidence of viral infection, and RSV was detected in 24.5%(94/383). Co-infections with RSV and other respiratory viruses(influenza A or B, adenovirus, para influenza 1, 2 or 3) were seen in children 5.5%(21/383). Over 90% of the RSV-positive children were under 2 years of age. RSV was detected throughout the year with peaks seen after the monsoon season.Children hospitalized with RSV infection were more likely to have been exposed to a shorter duration of breastfeeding of less than 3 mo. RSV positive children had a shorter hospital stay, although there were significant complications requiring intensive care. Use of antibiotics was high among those with RSV and non-RSV viral infections.CONCLUSION Our study provides evidence of a high proportion of RSV and other virusassociated ALRI among hospitalized children in India. RSV infection was associated with fewer days of hospital stay compared to other causes of lower respiratory infections. A high level of antibiotic use was seen among all respiratory virus-associated hospitalizations. These results suggest the need for implementing routine diagnostics for respiratory pathogens in order to minimize the use of unnecessary antibiotics and plan prevention strategies among pediatric populations.

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.

Cytokine responses in infants infected with respiratory syncytial virus

Introduction: Variability in severity of Respiratory Syncytial Virus (RSV) infection is reportedly due to differences in inflammatory response. Objective: To characterize the cytokine response in RSV+ infants aged 0 - 36 months and to relate their responses to disease severity. Methods: Nasopharyngeal aspirations (NPAs) were analyzed for RSV and IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-1RA, IL-4R, IFN-γ, sTNFR1, sTNFR2, and TNF-α. Clinical data were collected from the medical records. Results: We included 331 infants of whom 214 were RSV+. In comparison to RSV- infants, they had significantly higher levels of TNF-α, IL-6, IL-1β, and IFN-γ (p α, IL-6, and IL-1β. sTNFR1/2 were significantly increased in RSV+ infants. Hospitalized patients had significantly higher levels of TNF-α, sTNFR2, and IL-10 (p < 0.05) than non-hospitalized patients. The cytokine response could not be related to disease severity. We found no evidence of a skewed Th1/Th2 immune profile. Conclusion: In acute RSV disease, infected infants’ NPAs contain a significant amount of pro-inflammatory cytokines. Whether this response is beneficial or deleterious remains unanswered. Interpersonal variations in cytokine responses might be linked to an inherited tendency to variations in disease severity.

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.

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.

Respiratory syncytial virus infection in immunocompetent and immunocompromised murine

The purpose of this study is to distinguish respiratory syncytial virus （RSV） infection and immunology between immunocompetent and immunocompromised murine and to explore immune mechanism of RSV infection. At various time points after RSV infection of BALB/c mice and nude mice, pulmonary viral titers were assayed, RSV antigen was tested by direct immunofluorescent assay and immunohistochemistry. Pulmonary mRNA expressions of Toll like receptor （TLR）2 and TLR4 were assayed by RT-PCR. CD4^＋ ceils and CD8 ^＋ ceils in peripheral blood were examined by flow cytometry and plasma total IgE was assayed by ELISA. Leukocytes in bronchoalveolar lavage fluid （BALF） and pulmonary histology were identified to reflect airway inflammation. It was found that RSV titers of both mice peaked on the 3rd day post infection with a much higher level of viral titer in nude mice than in BALB/c mice and a longer viral duration in nude mice （over 9 days post infection） than in BALB/c mice （6 days post infection）. RSV infection induced higher viral antigen expression in nude mice （0.267 ±0.045） than in BALB/c mice （0. 168 ±0.031）. RSV infection enhanced pulmonary TLR4 expression of BALB/c mice （51.96% ±11.34%） and nude mice （48.96% ± 12.35%） compared with each control （34.04% ±10.06% and 32.37% ±9.87% respectively）. CD4^＋ peripheral blood ceils increased in RSV infected BALB/c mice （66.51% ±2.09% ） compared with the control BALB/c mice （51.63% ±5.90%）, and CD4^＋ ceils and CD8^＋ ceils were deficient in nude mice. RSV infection increased plasma total IgE in both mice, and BALB/c mice had a larger amount of IgE on the 7th day post infection （9.02 ng/ml ±2.90 ng/ml） and on the 14th day post infection （12.76 ng/ml ±4.15 ng/ml） than corresponding nude mice （3.72 ng/ml ±1.06 ng/ml and 7.62 ng/ml ±3.08 ng/ml respectively on the 7th and 14th day post infection）. RSV infected nude mice had more severe airway inflammation than infected BALB/c mice. It is concluded that BALB/c mice and nude mice presented similar RSV infectious characteristics. However, infection of nude mice showed higher viral titer with longer duration and more severe airway inflammation, lower level of plasm total IgE and CD4^＋ peripheral blood cells, but the similar pulmonary TLR4 expression with BALB/c mice.

Surfactant Protein D for Pathological Evaluation of Infant Acute Respiratory Distress Syndrome Caused by Respiratory Syncytial Virus Infection

Pediatric respiratory syncytial viral infection (RS) usually shows relatively good outcome;however, when it accompanies acute respiratory distress syndrome (ARDS), this becomes fatal. We experienced three pediatric patients with RS + ARDS, with all showing good outcome with steroid pulse therapy. We wish to emphasize;1) steroid pulse therapy may become an option for this condition, and 2) plasma KL-6 and surfactant protein D levels may become a biomarker reflecting the disease progression/condition. Patients were, aged 1 month, 1 year 5 months, and 1 year 11 months. In all three, the respiratory condition deteriorated rapidly, requiring invasive ventilator management. Although the effectiveness of steroid treatment for ARDS is controversial, very severe condition prompted us to employ steroid pulse therapy, after which, oxygenation rapidly improved without adverse events. Plasma KL-6 and surfactant protein D levels were measured during exacerbations of ARDS, steroid pulse therapy, and recovery. Surfactant protein D levels were closely associated with oxygenation, suggesting this substance level might be a biomarker of ARDS caused by the disruption of the alveolar epithelial lining and to understand oxygenation without time lag.

In vitro study on the antiviral activity of 9 extracts of traditional Chinese herbal medicine against the human respiratory syncytial virus

Objective:To study the in vitro virucidal activity of 9 extracts of traditional Chinese herbal medicine(the water extracts of Evodia lepta,Clausena lansium,Clerodendrum cyrtophyllum,Callicarpa nudiflora,Nauclea officinalis and Elaeagnus gonyanthes,the alcohol extracts of Nauclea officinalis,Elaeagnus gonyanthes and Zanthoxylumarmatum)on human respiratory syncytial virus(HRSV).Methods:The cytotoxic effect of the extracts on cells was evaluated by a cell viability assay using the CCK-8 method,a concentration of the extracts with cell viability greater than 50%was selected for the follow-up anti-HRSV effect assay,the 50%effective concentration(EC50)was assessed by an in vitro cell infection model.Results:The EC50s of the water extract from Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes were 0.05 mg/mL,0.03 mg/mL and 0.05 mg/mL,and the therapeutic index(TI)of them were 18.60,21.67 and 56.80 respectively.Conclusion:The water extracts of Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes possess the activity of anti-HRSV virus.

Genetic Characterization of Fusion Protein of Human Respiratory Syncytial Virus: Beijing

Objective Fusion protein is a subunit of the human respiratory syncytial virus(HRSV)and a potential vaccine candidate.Thus,a study on the genetic characteristics of F protein was considered important for further investigations in this field.The aim of this study was to determine the prevalence and genetic diversity of the F gene of HRSV infections in hospitalized pediatric patients in Beijing with acute lower respiratory tract infections and to compare the circulating genotypes that are currently found worldwide.Methods HRSV particles were amplified by RT-PCR and the PCR products were purified for sequencing.Further analysis was carried out by Bioedit and MEGA 3.0 biological software programs.Results Seventy-six samples(23.1%)were positive for HRSV.The percentage of cases in patients younger than 1year was 84.21%.Among the six Beijing isolates,four belonged to subgroup A,whose respective F genes shared97.0%-97.4%nucleotide sequence identity and 92.1%-93.0%amino acid sequence identity.The other two isolates belonged to subgroup B.Here,97.3%and 98.2%sequence identity were found at nucleotide and amino acid levels,respectively.Conclusions Phylogenetic analysis of nucleotide sequences revealed that those four isolates within subgroup A were monophyletic and closely related to each other,but those two within subgroup B distributed in two distinct clusters.Subgroup A and B strains co-circulated,indicating that two different transmission chains occurred in Beijing from 2003-2004.

Efficacy and mechanisms of Traditional Chinese Medicine prevention and treatment for respiratory viruses

Respiratory virus infection was the most common viral infection in clinical practice with the greatest impact,including the Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),posing a huge threat to the world's public health and human life safety.Commonly used antiviral drugs have obvious side effects and a narrow scope of application.Respiratory viruses are susceptible to infection,mutation,and prevalence,which also pose challenges to traditional antiviral drugs and vaccine development.Traditional Chinese Medicine(TCM)has a long history of treating infectious diseases,with many herbs and compounds.Its multi-component,multi-target and multi-path characteristics have made it have great advantages and potential in the development of new anti-respiratory virus drugs.This review summarized TCM for the prevention and treatment of common respiratory viruses,and provided new strategies for the research and development of new TCM antiviral drugs and for responding to infectious respiratory virus diseases.

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children

Background Respiratory syncytial virus(RSV)is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years,representing a major global healthcare burden.There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life.A multidisciplinary consensus development group comprising experts in epidemiology,infectious diseases,respiratory medicine,and methodology aims to develop the current consensus to address clinical issues of RSV infections in children.Data sources The evidence searches and reviews were conducted using electronic databases,including PubMed,Embase,Web of Science,and the Cochrane Library,using variations in terms for"respiratory syncytial virus","RSV","lower respiratory tract infection","bronchiolitis","acute","viral pneumonia","neonatal","infant""children",and"pediatric".Results Evidence-based recommendations regarding diagnosis,treatment,and prevention were proposed with a high degree of consensus.Although supportive care remains the cornerstone for the management of RSV infections,new monoclonal antibodies,vaccines,drug therapies,and viral surveillance techniques are being rolled out.Conclusions This consensus,based on international and national scientific evidence,reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections.Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

Integrating immunoinformatics and computational epitope prediction for a vaccine candidate against respiratory syncytial virus

Respiratory syncytial virus(RSV)poses a significant global health threat,especially affecting infants and the elderly.Addressing this,the present study proposes an innovative approach to vaccine design,utilizing immunoinformatics and computational strategies.We analyzed RSV's structural proteins across both subtypes A and B,identifying potential helper T lymphocyte,cytotoxic T lymphocyte,and linear B lymphocyte epitopes.Criteria such as antigenicity,allergenicity,toxicity,and cytokine-inducing potential were rigorously examined.Additionally,we evaluated the conservancy of these epitopes and their population coverage across various RSV strains.The comprehensive analysis identified six major histocompatibility complex class I(MHC-I)binding,five MHC-II binding,and three B-cell epitopes.These were integrated with suitable linkers and adjuvants to form the vaccine.Further,molecular docking and molecular dynamics simulations demonstrated stable interactions between the vaccine candidate and human Toll-like receptors(TLR4 and TLR5),with a notable preference for TLR4.Immune simulation analysis underscored the vaccine's potential to elicit a strong immune response.This study presents a promising RSV vaccine candidate and offers theoretical support,marking a significant advancement in vaccine development efforts.However,the promising in silico findings need to be further validated through additional in vivo studies.

维生素D受体基因多态性与RSV感染性毛细支气管炎的相关性研究

目的探讨维生素D受体(VDR)基因多态性与呼吸道合胞病毒(RSV)感染性毛细支气管炎的相关性。方法回顾性分析2023年1~6月佛山市妇幼保健院收治的60例RSV感染性毛细支气管炎患儿的临床资料,根据患儿临床表现分为轻症组(n=37)和重症组(n=23),另选择同期30例RSV阴性的健康体检儿童作为对照组。分别采用酶联免疫吸附法检测三组儿童的血清25-羟基维生素D[25(OH)D]、白细胞介素4(IL-4)、白细胞介素5(IL-5)水平,采用限制性片段长度多态性方法分析维生素D受体TaqI、FokI、ApaI、Bsm I基因多态位点,并比较三组儿童的基因型及等位基因频率情况。结果重症组患儿的血清25(OH)D水平为(52.67±12.22)nmol/L,明显低于轻症组的(65.57±13.54)nmol/L,而轻症组又明显低于对照组的(82.57±15.30)nmol/L,IL-4、IL-5分别为(152.28±22.47)ng/L、(51.83±9.83)ng/L,明显高于轻症组的(130.48±21.35)ng/L、(44.72±8.70)ng/L,而轻症组又明显高于对照组的(77.48±15.26)ng/L、(26.52±7.78)ng/L,差异均有统计学意义(P<0.05);经Hardy-Weinberg平衡定律检测不同组别间VDR基因序列等位基因分布的频率,数据均符合平衡定律(P<0.05);重症组患儿的VDR TaqI(rs731236)基因型TT及等位基因C均高于轻症组和对照组,基因型TC、等位基因T型频率均低于轻症组和对照组,差异均有统计学意义(P<0.05),但三组基因型的CC频率分布比较差异无统计学意义(P>0.05);三组儿童的VDR FokI(rs2228570)基因型频率分布比较差异均无统计学意义(P>0.05),但重症组患儿的等位基因C高于轻症组和对照组,T型频率低于轻症组和对照组,差异均有统计学意义(P<0.05);重症组患儿的VDR ApaI(rs7975232)基因型GG及等位基因G高于轻症组和对照组,基因型GT及等位基因A频率分布低于轻症组和对照组,差异均有统计学意义(P<0.05);重症组患儿的VDR Bsm I(rs1544410)基因型GA、AA及等位基因A均高于轻症组和对照组,基因型GG及等位基因G频率分布低于轻症组和对照组,差异均有统计学意义(P<0.05)。结论RSV感染性毛细支气管炎患儿的血清25(OH)D明显较低,VDR TaqI、FokI与患儿发病具有一定相关性,临床上可通过检测患儿VDR基因多态性状况,进一步分析患儿病情严重程度状况,并及时根据遗传体征状况提供针对性的预防和治疗方案。

布地奈德结合重组人干扰素α1b雾化吸入对RSV毛细支气管炎患儿肺功能指标的影响探讨

目的 探究对呼吸道合胞病毒(RSV)毛细支气管炎患儿应用布地奈德结合重组人干扰素α1b雾化吸入的效果及对其肺功能指标的影响。方法 选取92例RSV毛细支气管炎患儿,采用Excel表格分组法分为实验组与参照组,每组46例。参照组给予基础方案治疗,实验组给予布地奈德结合重组人干扰素α1b雾化吸入治疗。比较两组治疗效果、症状与体征消失时间、肺功能指标[潮气量(TV)、呼气峰流速(PEF)、达峰时间比(TPTEF/TE)及达峰容积比(VPTEF/VE)]及炎性因子[白细胞介素-10(IL-10)及干扰素-γ(INF-γ)]水平。结果 实验组治疗总有效率97.83%高于参照组的86.96%,组间对比差异成立(P<0.05)。实验组症状与体征消失时间中肺部啰音、三凹征、喘息、咳嗽消失时间分别为(4.65±0.88)、(2.96±0.52)、(3.70±1.08)、(5.18±1.30)d,均短于参照组的(5.41±1.13)、(4.20±0.87)、(4.22±0.96)、(2.79±1.24)d,组间对比差异成立(P<0.05)。实验组肺功能指标中TV、PEF、TPTEF/TE及VPTEF/VE分别为(7.51±1.29)ml/kg、(5.73±1.54)L/s、(26.91±7.08)%、(29.84±5.33)%,均高于参照组的(6.35±1.47)ml/kg、(4.02±0.83)L/s、(23.25±6.46)%、(26.91±4.32)%,组间对比差异成立(P<0.05)。实验组炎性因子指标中IL-10及INF-γ水平分别为(28.06±5.37)、(38.25±6.43)ng/L,均高于参照组的(15.64±7.22)、(29.36±5.24)ng/L,组间对比差异成立(P<0.05)。结论 布地奈德结合重组人干扰素α1b雾化吸入治疗RSV毛细支气管炎患儿的效果较好,临床症状与体征消失时间短,肺功能指标及炎性因子水平改善明显,具有重要临床应用价值。

IL2rg^(-/-)大鼠支持人RSV在体内的长期感染

目的为了克服已有人呼吸道合胞病毒(human respiratory syncytial virus,hRSV)动物模型的局限性,如半受纳性和感染持续时间短,本文利用TALEN基因编辑技术建立了IL2rg基因敲除(IL2rg^(-/-))的大鼠模型。方法用hRSV滴鼻感染该动物模型,观察感染期(0~35 d)的临床表征、体重及体温变化;记录不同时间点(滴鼻感染后第4、11、20、35天)鼻腔、气管、肺等呼吸道脏器的病毒总拷贝数;在观察终点(滴鼻感染后第35天)对感染动物的靶器官进行病理分析;观察不同时间点(滴鼻感染后第4、20、35天)外周血T、B、NK、NKT细胞的变化及不同时间点多种细胞因子的变化。结果(1)通过鼻内接种hRSV后,纯合的IL2rg基因敲除大鼠的呼吸道内能保持较高的病毒载量,鼻腔中病毒的平均峰值滴度能快速升至1×10^(10 )copies/g,至第5周时,病毒依然能维持复制,病毒载量亦可达到1×10^(7)copies/g。(2)但其鼻、气管和肺组织,无明显病变。(3)感染hRSV的IL2rg^(-/-)大鼠外周血B细胞含量有上升。(4)IL-6和MCP-1两种细胞因子都在感染前期上升,在观察终点回落。结论本研究基于TALEN技术建立了IL2rg^(-/-)大鼠模型,并发现该模型能很好地支持hRSV高水平复制和并长期感染,为抗病毒药物筛选、抗hRSV抗体体内效力评价,提供了良好的动物模型。