呼吸道合胞病毒被动免疫制剂研究进展

呼吸道合胞病毒(RSV)是造成世界范围内婴幼儿下呼吸道病毒性感染的主要原因之一,目前尚未研制出有效的疫苗,也没有特异性的治疗方法。被动免疫制剂能够有效预防RSV感染。静注RSV免疫球蛋白(RSV-IVIG)降低RSV易感儿童住院率,但其应用存在一定的局限性;抗RSVF蛋白的单抗Palivizumab是美国FDA批准的第一种用于传染病的人源化单克隆抗体,能够有效预防RSV感染、安全性高;其优化后的单抗Motavizumab亲和力和效力更强于Palivizumab。本文对RSV被动免疫制剂的研究进行了综述。     

抗呼吸道合胞病毒的免疫预防

呼吸道合胞病毒(RSV)感染是一个影响婴幼儿健康的全球性的问题,目前尚未有令人满意的治疗药物,免疫预防就显得尤为重要。近年研究表明,免疫预防在疫苗、单克隆抗体以及免疫球蛋白等领域均取得较大进展。     

呼吸道合胞病毒IgM抗体AlphaLISA快速检测方法的建立

呼吸道合胞病毒(Respiratory syncytial virus,RSV)属于副粘液病毒科,是一种下呼吸道感染最主要的RNA病毒.呼吸道合胞病毒感染是引起全球婴幼儿高致死率的呼吸道感染病原,仅次于疟疾,但用于检测RSV感染的选择相对较少.本文通过抗原抗体结合原理,建立呼吸道合胞病毒(RSV)IgM抗体AlphaLISA快速检测方法.小鼠抗人IgM单克隆抗体偶联的受体微球与临床血清样品中RSV特异性IgM抗体结合,RSV特异性IgM抗体再与生物素标记的RSV抗原结合,生物素连接偶联链霉亲和素的供体微球;受体微球和供体微球的距离被拉近小于200nm,680nm荧光激发供体微球生成单线态氧,扩散给受体微球,发射波长为520～620nm的荧光,荧光强度与血清中RSV特异性IgM抗体呈正比.结果显示,该方法批内变异系数与批间变异系数均小于10％,不与其他呼吸道病原体发生交叉反应,与间接免疫荧光法具有较好的一致性,总符合率达83.33％.该方法具有微量检测、快速省时、操作简便等优势,可快速检测RSV的IgM抗体,为早期确诊RSV感染提供高效可行方案.     

2017-2020年河南省漯河市呼吸道合胞病毒流行特征研究

呼吸道合胞病毒(Respiratory syncytial virus,RSV)是引起严重急性呼吸道感染(Severe acute respiratory infection,SARI)的一个重要病原,尤其以5岁以下儿童为主.为了解河南省漯河市SARI住院患者中RSV感染的流行病学和临床特征,为RSV预防控制及临床诊疗提供科学数据,本研究采集2017年10月至2020年8月河南省漯河市SARI住院病例的咽拭子,并收集流行病学和临床信息.采用荧光定量PCR方法鉴定RSV A/B阳性病例,分析其流行病学和临床特征.结果显示,本研究共入组1335例SARI病例,其中220例(16.48％)为RSV阳性,A和B亚型分别占64.55％和30.45％.RSV感染以5岁以下儿童为主(占91.36％),2岁以下婴幼儿占RSV感染病例的一半以上(占55.37％).RSV流行高峰出现在11月-次年1月,不同年份流行季可前后相差一个月.A﹑B亚型在不同月份可单独流行也可共流行.受新型冠状病毒肺炎疫情影响,2020年2-8月SARI病例数较往年同期减少60％以上,RSV阳性率在2020年2-8月降低为0.与非RSV感染组相比,RSV更易感染2岁以下儿童,下呼吸道感染占比更高(以支气管肺炎为主).本研究通过近3年SARI病例监测,揭示河南省漯河市RSV感染以冬春季常见,以下呼吸道感染为主,主要感染5岁以下儿童,其中2岁以下婴幼儿是防控重点人群.新型冠状病毒肺炎流行期间,由于限制性防控措施的干预,RSV感染大大降低.本研究将为RSV疫苗和单克隆抗体等预防性干预手段的使用策略提供基础数据.     

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65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44.60%(29/65),0～6个月婴幼儿感染率最高,为74.07%(20/27),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.     

抗人呼吸道合胞病毒融合糖蛋白单克隆抗体的制备及体外鉴定

目的:获得能稳定分泌抗人呼吸道合胞病毒(human respiratory syncytial virus, RSV)融合糖蛋白(fusion glycoprotein, F)单克隆抗体(monoclonal antibody, mAb)的杂交瘤细胞株,以期用于RSV感染的早期诊断和被动免疫治疗研究。方法:通过杂交瘤技术制备可特异性识别RSV F的单抗,体外鉴定生物学特性。结果:获得了可分泌抗RSV F蛋白的杂交瘤细胞株F8,体外连续传代培养2个月,能稳定分泌抗体F8,培养上清效价为1∶1000,亲和常数(Ka)为6.8×10⁸ L/mol。F8属IgG1型抗体,可特异性识别RSV F1亚单位的AA 205-222。免疫酶法蚀斑减少中和实验证实F8具有体外中和活性及融合抑制活性。结论:获得具有中和活性的抗RSV F蛋白的单克隆抗体,为RSV感染的早期诊断及被动免疫治疗等奠定了基础。     

ELISA检测RSV感染的研究

呼吸道合胞病毒(RSV)是婴幼儿呼吸道感染的重要病原之一,早期快速诊断RSV感染是防止本病蔓延,及时采取正确治疗措施的关键;所以,急待寻求快速诊断的方法。本试验建立了酶联免疫吸附测定(ELISA)检测RSV感染的方法。对其敏感性、特异性、重复性进行了检验;并在临床应用上与病毒分离和/或补体     

RSV疫苗研发的挑战和机遇

<正>呼吸道合胞病毒(respiratory syncyial virus,RSV)是引起婴幼儿严重急性下呼吸道感染最常见的病因,也是造成老年人和免疫功能不全人群疾病负担的重要原因。尚无许可的疫苗能解决这个重大公共卫生问题。虽然疫苗技术的进步导致最近重新掀起了RSV疫苗的研发,但防止RSV感染的免疫保护相关物和疫苗相关的加重呼吸道疾病的免疫学仍旧了解很少。     

呼吸道合胞病毒疫苗及其抗体制剂的研究进展

呼吸道合胞病毒(respiratory syncytial virus,RSV)感染是一个全球性的健康问题,目前临床上仍缺乏特异的治疗手段。接种疫苗主动免疫预防或使用抗体制剂被动免疫预防是避免重症感染和减少死亡的重要措施。针对不同的人群,须研制不同类型的RSV疫苗：减毒活疫苗对婴儿来说,可能是最佳选择;亚单位疫苗有引起增强型呼吸道疾病的风险,不适合RSV血清学阴性的婴幼儿接种,主要适用于老年人和孕妇。研发安全且有效的RSV疫苗难度大,虽然已有30余种RSV疫苗进入临床研究阶段,并显示出应用潜力,其中F纳米颗粒疫苗已率先进入III期临床试验,但在老年人和孕妇中未达预期效果。在RSV流行季节前,使用特异性抗体制剂也是预防高危人群严重RSV感染性疾病的有效手段。长效单克隆抗体MEDI8897比帕利珠单抗更具成本效益,已进入III期临床试验,且获得优先研发资格。多克隆免疫球蛋白RI-002已在免疫缺陷人群中显示出较好的预防效果,具有进一步研发的现实意义。本综述针对近年来RSV疫苗及其抗体的研究进展进行阐述,期望为RSV的预防提供参考。     

人呼吸道合胞病毒感染的预防和治疗研究进展

呼吸道合胞病毒（respiratory syncytial virus, RSV）会引起呼吸道和肺部感染,尤其是婴幼儿和老人,容易出现严重感染。尽管RSV感染对医疗保健产生了全球性影响,目前仍以支持性的治疗为主。在过去的几十年中,随着对RSV发病机制和免疫病理学的了解不断加深,RSV的预防策略取得了重大进步。自1966年RSV疫苗首次试验以来已经过去50多年,目前有两种RSV疫苗获批上市。综述了当前RSV感染的治疗方案（包括RSV特异性和非特异性）以及RSV疫苗的研发进展,以期为RSV的治疗及疫苗的研发提供参考。     

Passive transfer of respiratory syncytial virus (RSV) antiserum suppresses the immune response to the RSV fusion (F) and large (G) glycoproteins expressed by recombinant vaccinia viruses.

In young infants who possess maternally derived respiratory syncytial virus (RSV) antibodies, the antibody response to RSV glycoproteins is relatively poor, despite extensive replication of RSV. In the present study, it was found that cotton rat RSV hyperimmune antiserum suppressed the antibody response to the RSV glycoproteins but not the response to vaccinia virus antigens when the antiserum was passively transferred to cotton rats prior to infection with vaccinia recombinant viruses expressing the RSV envelope glycoproteins. The cotton rats which had their immune responses suppressed by passively transferred antibodies were more susceptible to infection with RSV than were animals inoculated with control serum lacking RSV antibodies. Furthermore, many of the immunosuppressed animals infected with the vaccinia recombinant viruses developed RSV glycoprotein antibodies which had abnormally low neutralizing activities. Thus, preexisting serum RSV antibodies had dramatic quantitative and qualitative effects on the immune response to RSV glycoproteins, which may explain, in part, the poor RSV antibody response of young human infants to infection with RSV. Our observations also suggest that immunosuppression by preexisting, passively acquired RSV antibodies may constitute a major obstacle to RSV immunoprophylaxis during early infancy, when immunization is most needed.     

Prophylactic and therapeutic testing of Nicotiana-derived RSV-neutralizing human monoclonal antibodies in the cotton rat model

Severe lower respiratory tract infection in infants and small children is commonly caused by respiratory syncytial virus (RSV). Palivizumab (Synagis^®), a humanized IgG₁ monoclonal antibody (mAb) approved for RSV immunoprophylaxis in at-risk neonates, is highly effective, but pharmacoeconomic analyses suggest its use may not be cost-effective. Previously described potent RSV neutralizers (human Fab R19 and F2–5; human IgG RF-1 and RF-2) were produced in IgG format in a rapid and inexpensive Nicotiana-based manufacturing system for comparison with palivizumab. Both plant-derived (palivizumab-N) and commercial palivizumab, which is produced in a mouse myeloma cell line, showed protection in prophylactic (p < 0.001 for both mAbs) and therapeutic protocols (p < 0.001 and p < 0.05 respectively). The additional plant-derived human mAbs directed against alternative epitopes displayed neutralizing activity, but conferred less protection in vivo than palivizumab-N or palivizumab. Palivizumab remains one of the most efficacious RSV mAbs described to date. Production in plants may reduce manufacturing costs and improve the pharmacoeconomics of RSV immunoprophylaxis and therapy.     

Respiratory syncytial virus: from pathogenesis to potential therapeutic strategies

Respiratory syncytial virus (RSV) is one of the most important viral pathogens causing respiratory tract infection in infants, the elderly and people with poor immune function, which causes a huge disease burden worldwide every year. It has been more than 60 years since RSV was discovered, and the palivizumab monoclonal antibody, the only approved specific treatment, is limited to use for passive immunoprophylaxis in high-risk infants; no other intervention has been approved to date. However, in the past decade, substantial progress has been made in characterizing the structure and function of RSV components, their interactions with host surface molecules, and the host innate and adaptive immune response to infection. In addition, basic and important findings have also piqued widespread interest among researchers and pharmaceutical companies searching for effective interventions for RSV infection. A large number of promising monoclonal antibodies and inhibitors have been screened, and new vaccine candidates have been designed for clinical evaluation. In this review, we first briefly introduce the structural composition, host cell surface receptors and life cycle of RSV virions. Then, we discuss the latest findings related to the pathogenesis of RSV. We also focus on the latest clinical progress in the prevention and treatment of RSV infection through the development of monoclonal antibodies, vaccines and small-molecule inhibitors. Finally, we look forward to the prospects and challenges of future RSV research and clinical intervention.     

NK cell immunophenotypic and genotypic analysis of infants with severe respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infection in infants. Reduced numbers of NK cells have been reported in infants with severe RSV infection; however, the precise role of NK cells during acute RSV infection is unclear. In this study the NK and T cell phenotypes, LILRB1 gene polymorphisms and KIR genotypes of infants hospitalized with RSV infection were analyzed. Compared to controls, infants with acute RSV infection showed a higher proportion of LILRB1+ T cells; in addition, a subgroup of infants with RSV infection showed an increase in LILRB1+ NK cells. No differences in NKG2C, NKG2A, or CD161 expression between RSV infected infants and controls were observed. LILRB1 genotype distribution of the rs3760860 A>G, and rs3760861 A>G single nucleotide polymorphisms differed between infants with RSV infection and healthy donors, whereas no differences in any of the KIR genes were observed. Our results suggest that LILRB1 participates in the pathogenesis of RSV infection. Further studies are needed to define the role of LILRB1+ NK in response to RSV and to confirm an association between LILRB1 polymorphisms and the risk of severe RSV infection.     

Identification of nucleolin as a cellular receptor for human respiratory syncytial virus

Human respiratory syncytial virus (RSV) causes a large burden of disease worldwide. There is no effective vaccine or therapy, and the use of passive immunoprophylaxis with RSV-specific antibodies is limited to high-risk patients. The cellular receptor (or receptors) required for viral entry and replication has yet to be described; its identification will improve understanding of the pathogenesis of infection and provide a target for the development of novel antiviral interventions. Here we show that RSV interacts with host-cell nucleolin via the viral fusion envelope glycoprotein and binds specifically to nucleolin at the apical cell surface in vitro. We observed decreased RSV infection in vitro in neutralization experiments using nucleolin-specific antibodies before viral inoculation, in competition experiments in which virus was incubated with soluble nucleolin before inoculation of cells, and upon RNA interference (RNAi) to silence cellular nucleolin expression. Transfection of nonpermissive Spodoptera frugiperda Sf9 insect cells with human nucleolin conferred susceptibility to RSV infection. RNAi-mediated knockdown of lung nucleolin was associated with a significant reduction in RSV infection in mice (P = 0.0004), confirming that nucleolin is a functional RSV receptor in vivo.     

Trends in Respiratory Syncytial Virus and Bronchiolitis Hospitalization Rates in High-Risk Infants in a United States Nationally Representative Database, 1997–2012

BackgroundRespiratory syncytial virus (RSV) causes significant pediatric morbidity and is the most common cause of bronchiolitis. Bronchiolitis hospitalizations declined among US infants from 2000‒2009; however, rates in infants at high risk for RSV have not been described. This study examined RSV and unspecified bronchiolitis (UB) hospitalization rates from 1997‒2012 among US high-risk infants.MethodsThe Kids’ Inpatient Database (KID) infant annual RSV (ICD-9 079.6, 466.11, 480.1) and UB (ICD-9 466.19, 466.1) hospitalization rates were estimated using weighted counts. Denominators were based on birth hospitalizations with conditions associated with high-risk for RSV: chronic perinatal respiratory disease (chronic lung disease [CLD]); congenital airway anomalies (CAA); congenital heart disease (CHD); Down syndrome (DS); and other genetic, metabolic, musculoskeletal, and immunodeficiency conditions. Preterm infants could not be identified. Hospitalizations were characterized by mechanical ventilation, inpatient mortality, length of stay, and total cost (2015$). Poisson and linear regression were used to test statistical significance of trends.ResultsRSV and UB hospitalization rates were substantially elevated for infants with higher-risk CHD, CLD, CAA and DS without CHD compared with all infants. RSV rates declined by 47.0% in CLD and 49.7% in higher-risk CHD infants; no other declines in high-risk groups were observed. UB rates increased in all high-risk groups except for a 22.5% decrease among higher-risk CHD. Among high-risk infants, mechanical ventilation increased through 2012 to 20.4% and 13.5% of RSV and UB hospitalizations; geometric mean cost increased to $31,742 and $25,962, respectively, and RSV mortality declined to 0.9%.ConclusionsAmong high-risk infants between 1997 and 2012, RSV hospitalization rates declined among CLD and higher-risk CHD infants, coincident with widespread RSV immunoprophylaxis use in these populations. UB hospitalization rates increased in all high-risk groups except higher-risk CHD, suggesting improvement in the health status of higher-risk CHD infants, potentially due to enhanced surgical interventions. Mechanical ventilation use and RSV and UB hospitalization costs increased while RSV mortality declined.     

Effect of breast feeding on the development of anti-idiotype antibody response to F glycoprotein of respiratory syncytial virus in infant mice after post-partum maternal immunization

Groups of lactating BALB/c mice were immunized in the immediate postpartum period with high doses of mAb (Ab-1) to the F-glycoprotein (F-gp) of respiratory syncytial virus (RSV). This antibody possessed neutralizing activity against the whole virus. The immune response to F-gp was studied in the breast feeding infant mice of such mothers at regular intervals before and after weaning. All infant mice exhibited anti-F-gp activity in serum, which was detected until 6 wk of age. Splenic cells of such breast feeding infant mice collected after weaning exhibited in vitro synthesis of antibody against Ab-1, the antibody previously used for maternal immunization. Subsequent immunization with homologous purified RSV F-gp resulted in a booster response for IgG, IgM, and plaque-neutralizing antibody to the immunizing RSV protein and to the whole virus in the infants primed via breast feeding. The enhanced antibody response was specific for the antigenic epitopes of the virus protein recognized by the monoclonal antibody used for maternal immunization. Similar booster effect was seen in control infants of nonimmunized mothers who were immunized with a polyclonal Ab-2 prepared by repeated immunization with Ab-1 in DBA/2 mice. These data demonstrate induction of RSV-specific anti-idiotype antibody in the neonates via the process of breast feeding, secondary to maternal immunization after the delivery of the neonate. Use of idiotypic vaccines in the mother and the transfer of RSV-specific idiotypes may offer an alternate approach to the development of effective immunoprophylaxis for RSV infection in early infancy.     

Plasma interferon-gamma, interleukin-10 and soluble markers of immune activation in infants with primary adenovirus (ADV) and respiratory syncytial virus (RSV) infection

Adenovirus (ADV) and respiratory syncytial virus (RSV) are etiological agents of acute respiratory tract infection in infants. Long-term prognosis of ADV infection includes severe lung damage, bronchiectasis and hyperlucent lung, while RSV infection is associated with development of recurrent wheezing and subsequent asthma. These differences may be related to differences in the primary immune responses elicited by these viruses. In this paper, we investigated the type of cytokine responses and the magnitude of immune activation in ADV and RSV infections in infants. We examined plasma concentrations of interferon-gamma (IFN-gamma), interleukin-10 (IL-10), soluble interleukin-2 receptor (sCD25) and soluble tumor necrosis factor receptor II (sTNFR-II) in previously healthy infants during the acute phase of primary ADV infection (n = 21) and RSV infection (n = 68), and in uninfected controls (n = 44). In ADV-infected infants, IFN-gamma plasma levels were significantly higher than those observed in RSV cases and the control group (p < 0.05). RSV cases did not show any differences in IFN-gamma plasma levels compared to the other groups. sCD25 levels were significantly higher in ADV- and RSV-infected infants than in controls (p < 0.0001), and higher in ADV than in RSV cases (p < 0.05). sTNFR-II levels were significantly higher in RSV- and ADV-infected infants than in controls (p < 0.0001, p < 0.05, respectively), and higher in RSV than in ADV infection (p < 0.05). No significant differences were observed in IL-10 plasma concentrations between the three groups. These results indicate that ADV and RSV infections in infants differ significantly with regard to the magnitude of production of interferon-gamma and soluble immune activation markers sCD25 and sTNFR-II. These immunological differences may be involved in the different clinical outcomes associated with these viral infections.     

Innate immune recognition of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in infants and young children. Severe clinical manifestation of RSV infection is a bronchiolitis, which is common in infants under six months of age. Recently, RSV has been recognized as an important cause of respiratory infection in older populations with cardiovascular morbidity or immunocompromised patients. However, neither a vaccine nor an effective antiviral therapy is currently available. Moreover, the interaction between the host immune system and the RSV pathogen during an infection is not well understood. The innate immune system recognizes RSV through multiple mechanisms. The first innate immune RSV detectors are the pattern recognition receptors (PRRs), including toll-like receptors (TLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), and nucleotide-biding oligomerization domain (NOD)-like receptors (NLRs). The following is a review of studies associated with various PRRs that are responsible for RSV virion recognition and subsequent induction of the antiviral immune response during RSV infection. [BMB Reports 2014; 47(4): 184-191]