Apoferritin as a virus-like particle for the display of multiple virulence factors for vaccine development

疫苗为保护动物和人类免受多种病原体的侵害提供了一种高效、具有成本效益的方法，并避免了大规模使用抗生素和抗病毒药物的需要。这减少了用于治疗受感染牛的药物数量，并最大限度地减少了随后可能出现在肉类、牛奶或其他乳制品等食品中的药物残留和代谢物。自爱德华·詹纳（Edward Jenner）时代以来，疫苗要么使用完整的活性良性病毒，如牛痘病毒，以防止天花感染，要么使用化学或热处理的致病病毒或细菌，这些病毒或细菌无法复制/繁殖，但在接种疫苗的动物中产生保护性免疫反应。如果疫苗制备正确，病毒/病原体完全失活，这种方法对许多疾病都有效，但对于流感病毒等迅速变异的病原体，有必要每年制备新的复合疫苗，以确保病原体不会发生变异，从而逃避免疫系统。为了制造更有效的保护性疫苗，研究人员已经不再使用失活的整个病原体，而是更倾向于生产基于其中独特的蛋白质和糖的疫苗，这些蛋白质和糖既能刺激体液免疫反应，也能刺激细胞免疫反应。为了达到最有效的效果，这些结构需要在纳米颗粒上以多个副本呈现给免疫系统，理想的直径为10-40纳米，并且需要将来自单一病原体的几种不同蛋白质或来自单一病原体的同一蛋白质的几种不同突变体呈现给免疫系统，以抵消病原体随时间的变化。为了实现这一目标，研究人员研究了许多病毒和其他自然产生的蛋白质胶囊类型，并由此产生了几种人类疫苗，包括针对肝炎和乳头瘤病毒的疫苗。我们建议使用载铁蛋白作为纳米颗粒，因为它可以通过附着多种病原体蛋白而快速廉价地大量生产。由于载铁蛋白可以通过改变溶液的pH值自组装成一个高度组织化的蛋白质胶囊，因此它可以发展成一个模块化系统，在这个系统中，不同抗原的大组合可以快速组合，产生适合疫苗接种的纳米颗粒。这将使新疫苗能够迅速产生，以应对迅速演变的病原体。为了演示这项技术，我们将生产载铁蛋白复合物，该复合物显示奶牛和山羊乳腺炎感染中涉及的细菌的蛋白质。目前在英国，由于乳腺炎，乳制品行业每年损失的牛奶产量相当于12万头奶牛的产量，因此根除这种疾病将减少畜群规模，从而释放它们占用的土地和生产替代农业饲料所需的土地。这也将大大减少英国的牛二氧化碳排放量。载铁蛋白技术可广泛用于开发一系列动物和人类健康疫苗。

Vaccines provide an efficient, cost effective method of protecting animals and humans against a large range of pathogens and avoid the need for large scale use of antibiotics and antiviral agents. This reduces the quantities of drugs used to treat infected cattle and minimizes the drug residues and metabolites that can subsequently appear in foodstuffs such as meat, milk or other dairy products. Since the time of Edward Jenner, vaccines have used either whole active benign viruses such as cowpox virus for protection against smallpox infections or chemically or heat-treated pathogenic viruses or bacteria that are unable to replicate/reproduce but produce a protective immune response in the animal being vaccinated. Provided the vaccines are correctly prepared and the virus/pathogen is completely deactivated, this approach works for a number of diseases, but for pathogens such as the influenza virus that rapidly mutates it is necessary to prepare new complex vaccines on an annual basis in order to ensure that the pathogen has not mutated such that it can evade the immune system. In order to make more efficient protective vaccines, researchers have moved away from using deactivated whole pathogens, preferring to generate vaccines based on unique proteins and sugars in them that stimulate both a humoral and cellular immune response. In order to be most effective these structures need to be presented to the immune system in multiple copies on nanoparticles ideally 10-40 nm in diameter and either several different proteins from a single pathogen or several different mutants of the same proteins from a single pathogen need to be presented to the immune system to counteract the changes in the pathogen over time. To achieve this researchers have examined a number of virus and other naturally occurring types of protein capsules and several human vaccines have been generated from these including ones against hepatitis and papillomavirus. We are proposing to use apoferritin as the nanoparticle as it can be produced in large quantities quickly and cheaply with a wide range of pathogen proteins attached. Because apoferritin can self-assemble in to a highly organised protein capsule by changing the pH of the solution, it can be developed into a modular system where large combinations of different antigens can be combined rapidly to generate nanoparticles suitable for vaccination. This would allow new vaccines to be generated rapidly in response to quickly evolving pathogens. To demonstrate the technology we will produce apoferritin-complexes which display proteins from bacteria involved in mastitis infections in cows and goats. Currently in the UK the dairy industry loses milk production equivalent to that of 120,000 cows per year due to mastitis and therefore eradicating this disease would reduce herd sizes freeing up both the land they occupy and the land required to produce their feed for alternative agriculture use. This would also significantly reduce the bovine carbon dioxide generation of the UK.The apoferritin technology could be widely exploited to develop a range of vaccines for both animal and human health.