Cross Reacting Polysaccharides (H. influenzae types a and b, and B. pumilus)

交叉反应多糖（a 型和 b 型流感嗜血杆菌，以及短小芽孢杆菌）

• 批准号: 8553872
• 负责人: Rachel Schneerson
• 金额: $ 16.7万
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8553872
• 关键词: 4 year old; Acetylglucosamine; Acids; Alaska Native; Amino Sugars; Antibodies; Antigens; Apache Indians; Bacteremia; Bovine Serum Albumin; Brazil; Canada; Cell Wall; Centers for Disease Control and Prevention (U.S.); Child; Clinical; Complement; Conjugate Vaccines; Data; Development; Disease; Disease Outbreaks; Dose; Double-Blind Method; Drug Formulations; Enzyme-Linked Immunosorbent Assay; Goals; Haemophilus influenzae; Haemophilus influenzae type b bacteria; Herd Immunity; Immunization; Incidence; Infant; Infection; Laboratories; Lansing Virus; Licensing; Link; Manitoba; Meningitis; Methods; Monosaccharides; Mus; Netherlands; Oligosaccharides; Persons; Polysaccharides; Population; Property; Proteins; Randomized; Rattus; Reporting; Research Personnel; Resistance; Ribitol; Safety; Serum; Site; South Africa; Structure; Sugar Alcohols; Testing; Tetanus Toxoid; Time; United States; Vaccination; Vaccines; Virulence; Virulent; bactericide; base; control trial; dimer; immunogenicity; inorganic phosphate; pathogen; phosphodiester; population based; programs; vaccine development

The investigator for this report has retired. There is no report on progress. Following is last year's report. Herd immunity followed widespread use of the Haemophilus influenzae type b (Hib) conjugate vaccine, and the near-elimination of Hib led to speculation that other Haemophilus influenzae (Hi) types may emerge as causes of meningitis. For example, in Brazil, the incidence of Hib meningitis decreased by 69 percent during the first year after initiation of Hib conjugate immunization while the incidence of Hia meningitis increased 8-fold. The Netherlands Reference Laboratory reported that type a was observed only in children younger than 4 years old. Properties of Hia and Hib CP. Hi may be classified into three virulence groups of two, related to their CP structures. Types a and b, which are the most virulent, are composed of a neutral sugar, an alcohol (ribitol), and a phosphodiester; types c and f are composed of an N-acetylated aminosugar, a monosaccharide, and a phosphodiester; and (3) types d and e have a repeat unit of an N-acetylglucosamine and N-acetylmannosamineuronic acid. Compared with the other four types, Hib and Hia are resistant to the bactericidal effects of complement alone. Challenge of infant rats showed that the 50 percent infective dose (ID50) for bacteremia of both Hib and Hia was several logs lower than of the other types. Intranasal challenge of infant rats with type b or type a resulted in 55 to 90 percent bacteremia with type b and 35 percent with type a. The other types were not invasive. Invasive diseases caused by Hia. Rates of Hia disease have remained constant in the United States despite Hib vaccination. From 1998 to 2002, the Emerging Infections Program of the CDC conducted active laboratory- and population-based surveillance for Hi disease in data from nine sites with approximately 35 million people. Seventeen of 1,743 invasive isolates were Hia, which is an important cause of meningitis in certain populations such as White Mountain Apache Indian childrenwith an annual incidence of 254 cases/100,000 children of Hia meningitis. Hammitt et al. (Pediatr Infect Dis J 2005;24:453) reported an outbreak of invasive Hia disease among Native Alaska infants. During a 6-month period in two proximate villages, five Hia cases were documented. In Brazil, an incidence of Hia meningitis of 0.16 cases/100,000 person-years was reported. South Africa and native populations in Manitoba Canada also report Hia meningitis in children. Hia vaccine. The number of Hia cases is too low for a randomized, double-blinded, controlled trial. Yet, precedent exists for adding types within a species to a vaccine without evidence for efficacy. For example, the licensing of several pneumococcal types, including meningococcal groups Y and W135 and poliovirus type 2, was based on their safety and immunogenicity. The structural, experimental, and clinical properties of Hia CP closely resemble those of type b, and the increasing number of reports of Hia-invasive disease suggests that development of an Hia conjugate is warranted. Methods for conjugating type b CP to a protein are applicable to Hia. D-1,5-ribitolphosphate is a constituent of the CPs of Hia and Hib. We reported that the cell wall polysaccharide (PS) of B. pumilus Sh18 contains a poly-1,5-ribitolphosphate as a major component and that antibodies induced in mice by such conjugate cross-reacted with both Hia and Hib. We synthesized polyribitolphosphate chains containing either 8 or 12 repeat units, with the terminal keto groups used for conjugation to aminooxylated bovine serum albumin (BSA or tetanus toxoid. We injected the conjugates into mice, three times at 2-week intervals at 2.5 g/mouse and obtained sera a week later. ELISA demonstrated antibodies to both Hia and Hib, with the octamer conjugate a better immunogen than the dodecamer conjugate. Some of the tested sera showed bactericidal activity against both type a and type b as roughly correlated with their ELISA values. Other constructs and formulations arebeing studied. As an alternative to the native polysaccharide-based vaccine, we are developing a conjugate vaccine against Hia by chemically synthesizing fragments of its capsular material which is built up by glucosyl-ribitol-phosphate repeating units. So far we have synthesized the glucosyl-ribitol unit and were able to assemble a dimer of the repeating unit. Construction of higher-membered phosphodiester-linked oligosaccharides is in progress.

本报告的研究者已退休。目前还没有进展报告。以下是去年的报告。 在广泛使用B型流感嗜血杆菌（Hi B）结合疫苗后出现了群体免疫，Hi B几乎被消灭，这导致人们猜测其他流感嗜血杆菌（Hi）类型可能是脑膜炎的原因。例如，在巴西，Hib脑膜炎的发病率在开始Hib结合物免疫后的第一年内下降了69%，而Hia脑膜炎的发病率增加了8倍。荷兰参考实验室报告说，A型仅在4岁以下的儿童中观察到。 Hia和Hib CP的性质。 根据CP结构的不同，Hi可分为3个毒力类群。毒性最强的a型和B型由中性糖、醇（核糖醇）和磷酸二酯组成; c型和f型由N-乙酰化氨基糖、单糖和磷酸二酯组成;（3）d型和e型具有N-乙酰葡糖胺和N-乙酰甘露糖胺神经糖醛酸的重复单元。与其他四种类型相比，Hib和Hia对单独补体的杀菌作用具有抗性。幼鼠攻毒试验表明，Hib和Hia菌血症的半数感染剂量（ID_（50））均比其他类型菌血症的ID_（50）低几个对数。用B型或A型对幼鼠进行鼻内攻击，结果B型菌血症为55%至90%，A型菌血症为35%。其他类型没有侵入性。 Hia引起的侵袭性疾病。 尽管接种了Hib疫苗，美国Hia疾病的发病率仍然保持不变。从1998年到2002年，疾病预防控制中心的新发感染项目对来自9个地点约3500万人的Hi疾病数据进行了积极的实验室和人群监测。1,743个侵袭性分离株中有17个是Hia，这是某些人群脑膜炎的重要原因，例如白色山区阿帕奇印第安儿童，Hia脑膜炎的年发病率为254例/100，000名儿童。Hammitt等人（Pediatr Infect Dis J 2005;24：453）报道了在阿拉斯加土著婴儿中爆发的侵袭性Hia疾病。在6个月期间，在两个邻近的村庄，记录了5例Hia病例。在巴西，Hia脑膜炎的发病率为0.16例/100，000人年。南非和加拿大马尼托巴的土著居民也报告了儿童Hia脑膜炎。 HIA疫苗。 Hia病例的数量对于随机、双盲、对照试验来说太少了。然而，在没有有效性证据的情况下将物种内的类型添加到疫苗中的先例存在。例如，对包括Y群和W135群脑膜炎球菌以及2型脊髓灰质炎病毒在内的几种肺炎球菌的许可是基于其安全性和免疫原性。Hia CP的结构、实验和临床性质与B型CP的结构、实验和临床性质非常相似，并且越来越多的Hia侵袭性疾病报告表明有必要开发Hia缀合物。将B型CP与蛋白质缀合的方法适用于Hia。D-1，5-核糖醇磷酸是Hia和Hib CP的一种成分。本文报道了B. pumilus Sh 18含有聚-1，5-核糖醇磷酸作为主要组分，并且通过这种缀合物在小鼠中诱导的抗体与Hia和Hib两者交叉反应。我们合成了含有8或12个重复单元的聚核糖醇磷酸链，末端酮基用于与氨氧基化牛血清白蛋白（BSA或破伤风类毒素）缀合。我们将缀合物以2.5g/小鼠以2周间隔注射到小鼠中三次，并在一周后获得血清。ELISA证明了Hia和Hib的抗体，八聚体缀合物比十二聚体缀合物是更好的免疫原。一些测试的血清显示出对a型和B型的杀菌活性，大致与它们的ELISA值相关。 其他结构和配方正在研究中。作为天然多糖基疫苗的替代品，我们正在开发一种针对Hia的缀合物疫苗，其通过化学合成由葡糖基-核糖醇-磷酸重复单元构建的其荚膜材料的片段。到目前为止，我们已经合成了葡萄糖基-核糖醇单元，并能够组装重复单元的二聚体。高分子磷酸二酯连接寡糖的构建正在进行中。