Glycoengineering of Veterinary Vaccines

健康饲养牲畜对英国的经济和繁荣至关重要。此外，一些受感染的牲畜是人类疾病的来源，特别是通过食源性感染。从历史上看，疫苗是减少人类传染病负担的最成功和最有效的干预措施。相比之下，疫苗在兽医学中的应用是初级的，主要是由于经济上需要降低为动物接种疫苗的成本，以及我们对引起动物疾病的病原体的了解落后于人类。成功疫苗的一个决定性特征是能够在副作用最小的情况下引起持久的保护性免疫。许多最成功的人类疫苗是糖缀合物，这是一种蛋白质与聚糖结合的组合，可诱导t细胞依赖和独立的免疫反应，产生保护性和持久的免疫。目前获得许可的人糖结合疫苗的例子包括针对流感嗜血杆菌、脑膜炎奈瑟菌和肺炎链球菌的疫苗，其中聚糖（脂多糖或荚膜多糖）与免疫原性载体蛋白化学偶联。然而，这些疫苗的生产需要多步骤的程序，这些程序通常是复杂和昂贵的，并且可能出现批次之间的差异。我们最近开发了蛋白聚糖偶联技术（PGCT），通过在大肠杆菌细胞中单步表达疫苗，可以克服化学合成糖结合疫苗所需的复杂程序。将PGCT应用于兽用疫苗的优点是：(1)糖结合疫苗可以低成本生产，(2)“任何聚糖”与“任何蛋白质”偶联的灵活性促进了疫苗组合的生产，从而有机会评估更多种类的候选疫苗，以及(3)可以生产针对一种以上疾病的联合疫苗，进一步降低成本并避免需要施用多种疫苗（或抗生素）。在这项研究中，我们将利用PGCT生产廉价的三联疫苗，以减少大肠杆菌、沙门氏菌、空肠弯曲杆菌/大肠杆菌和产气荚膜杆菌的感染。这不仅将保护禽群免受严重疾病的侵害，而且还将保护人类免受最常见的食源性感染，包括沙门氏菌和弯曲杆菌引起的感染。此外，我们将构建和评估双Coxiella/C。产气荚膜菌疫苗用于保护牛、绵羊和山羊免受严重疾病的侵害。这种疫苗还可以防止q热向人类传播，q热是由传染性很强的伯氏克希菌病原体引起的。本建议中制定的原则随后可广泛应用于生产针对大多数动物物种的廉价有效疫苗，并有望在兽医疫苗生产方面开辟新天地。

A healthily maintained livestock is essential for the economy and prosperity of the UK. Additionally some infected livestock are the source of human diseases, particularly through foodborne infections. Historically, vaccines have been the most successful and effective intervention to reduce the burden of infectious diseases in humans. By contrast, the application of vaccines in veterinary medicine is rudimentary, mainly due to the economic necessity for reduced costs to vaccinate animals and because our knowledge of the pathogens that cause animal diseases lags behind that of human counterparts. A defining characteristic of a successful vaccine is the ability to evoke long-lasting protective immunity with minimal side effects. Many of the most successful human vaccines are glycoconjugates, a combination of a protein coupled to a glycan, which induces both a T-cell dependent and independent immune response generating a protective and lasting immunity. Examples of currently licensed human glycoconjugate vaccines include those against Haemophilus influenzae, Neisseria meningitidis and Streptococcus pneumoniae, in which glycans (lipopolysaccharides or capsular polysaccharides) are chemically coupled to immunogenic carrier proteins. However, the production of these vaccines requires multistep procedures that are often complex and expensive, and can exhibit batch-to-batch variation.We recently developed Protein Glycan Coupling Technology (PGCT) that can overcome the complex procedures required for chemically synthesising glycoconjugate vaccines by expressing the vaccine in an Escherichia coli cell in a single-step procedure. The advantages of applying PGCT to veterinary vaccines are (i) glycoconjugate vaccines can be produced at low cost, (ii) the flexibility of coupling "any glycan" with "any protein" facilitates the production of vaccine combinations providing the opportunity to evaluate a greater variety of vaccine candidates, and (iii) combination vaccines against more than one disease can be produced, further reducing cost and obviating the need to administer multiple vaccines (or antibiotics).In this study we will use PGCT to produce inexpensive triple combination poultry vaccines to reduce infection from E. coli, Salmonella, Campylobacter jejuni/coli and C. perfringens. This will not only protect poultry flocks from severe disease but would also protect the human population from the most common foodborne infections including those caused by Salmonella and Campylobacter. In addition we will construct and evaluate a dual Coxiella/C. perfringens vaccine to protect cattle, sheep and goats against severe disease. This vaccine would also prevent the spread of Q-fever to humans, which is caused by the highly infectious Coxiella burnetii pathogen. The principles developed in this proposal could subsequently be widely applied to produce inexpensive efficacious vaccines against most animal species and promise to break new ground in veterinary vaccine production.