Towards an in vitro system of predictive biomarkers of in vivo liposome efficacy

建立体内脂质体功效预测生物标志物的体外系统

• 批准号: NC/L000261/1
• 负责人: Andrew Devitt
• 金额: $ 9.49万
• 依托单位: Aston University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NC%2FL000261%2F1
• 关键词: Towards; vitro; system; predictive; biomarkers

Vaccines are designed to induce protective immune responses in individuals without the need for natural infection. They contain 'antigens' (whole pathogens or sub-units of pathogens) against which an immune response is desirable. Adjuvants are an important component of vaccines, especially those that do not contain live pathogens, as adjuvants increase the efficacy of the antigenic material that is provided. Given that 'live vaccines', due to their less tolerable safety profile, are rejected in favour of more advanced sub-unit and DNA vaccines, adjuvants thus play a key role in vaccine development. There are a range of different adjuvants currently available but the use of liposomes (a hollow 'bag' of lipid) are highly attractive as they have the advantage that they are both adjuvant in nature and also have the capacity to deliver antigens (e.g. within the hollow core or on their surface). This project is directed towards the effective in vitro screening of liposomes for the identification of more effective adjuvant preparations.With every new vaccine formulation, many in vivo tests are essential to ensure efficacy and safety of the vaccine. Thus the generation of novel liposome formulations has tended to be evolutionary rather than revolutionary i.e. minor modifications based on a formulation that has shown some use. Such an incremental approach is slow and the ability to screen large libraries of formulations will speed the development of new and more effective vaccines for the prevention of a range of important diseases (e.g. TB, HIV, malaria and chlamydiae). However currently, large-scale screening is prohibitively expensive in animals and man-hours.In this project we will test liposome formulations that have already been tested in vivo (ranging from effective-ineffective) including formulations with varying physical and chemical characteristics and those that generate different 'types' of immune responses, so called Th1 and Th2 responses. This will allow us to data mine both effective and ineffective responses without further in vivo studies. Generation of the appropriate 'type' of immune response for each disease is critical to the success of any vaccine. For example, Th1 responses protect against pathogens such as viruses that live within cells and thus a Th2 response would not be desirable. We will test our liposomes in a range of in vitro tests and by integrating the results in a 'systems biology' approach, we will identify a 'fingerprint' of in vitro biological activity that is predictive of in vivo efficacy. This will save the use of very significant numbers of animals and will improve the drug-discovery pipeline, as we will then be able to efficiently screen large libraries of formulations to identify leads for further work. This project will thus speed the development of novel liposomes and vaccines.Our unique panel of in vitro assays has been carefully selected to be relevant to the generation of immune responses. Once a vaccine is injected, a vaccine must attract and activate key immune system cells known as antigen presenting cells (APC). Consequently we will assess in vitro the behavior of APC in the presence of each liposome. We will assess (A) migration of APC to liposomes; (B) association of liposomes with APC; (C) liposome-activation of APC (that are usually quiescent) and (D) correlate the in vitro results with known in vivo efficacy.Our approach will identify key in vitro markers of in vivo efficacy of liposomes. This 'biomarker fingerprint' will then be used in future work to screen libraries of formulations in vitro for likely in vivo efficacy. This approach will identify key biomarkers of effective in vivo preparations of liposomes. The net effect of this will be to speed and make more efficient the vaccine development pipeline with significant beneficial impact for human health.

疫苗被设计成在个体中诱导保护性免疫应答而不需要自然感染。它们含有“抗原”（完整的病原体或病原体的亚单位），免疫应答是期望的。佐剂是疫苗的重要组成部分，尤其是那些不含活病原体的疫苗，因为佐剂增加了所提供的抗原材料的效力。鉴于“活疫苗”由于其耐受性较差的安全性而被更先进的亚单位和DNA疫苗所拒绝，因此佐剂在疫苗开发中发挥着关键作用。目前有一系列不同的佐剂可供使用，但使用脂质体（脂质的中空“袋”）是非常有吸引力的，因为它们具有这样的优点，即它们在性质上既是佐剂，也具有递送抗原的能力（例如在中空核内或在其表面上）。本项目旨在对脂质体进行有效的体外筛选，以鉴定更有效的佐剂制剂。对于每一种新的疫苗制剂，都必须进行许多体内试验，以确保疫苗的有效性和安全性。因此，新型脂质体制剂的产生往往是渐进的而不是革命性的，即基于已显示出一些用途的制剂的微小修改。这种渐进的方法是缓慢的，筛选大量制剂库的能力将加快开发新的和更有效的疫苗，以预防一系列重要疾病（如结核病、艾滋病毒、疟疾和衣原体）。然而，目前，大规模的筛选在动物和工时上过于昂贵。在本项目中，我们将测试已经在体内测试过的脂质体制剂（从有效到无效），包括具有不同物理和化学特性的制剂以及产生不同“类型"免疫应答（所谓的Th 1和Th 2应答）的制剂。这将使我们能够在没有进一步体内研究的情况下对有效和无效的反应进行数据挖掘。针对每种疾病产生适当的“类型”免疫应答对任何疫苗的成功都至关重要。例如，Th 1应答保护免受病原体如生活在细胞内的病毒的侵害，因此Th 2应答将是不期望的。我们将在一系列体外测试中测试我们的脂质体，并通过将结果整合到“系统生物学”方法中，我们将确定体外生物活性的“指纹”，该指纹可预测体内功效。这将节省大量动物的使用，并将改善药物发现管道，因为我们将能够有效地筛选大型配方库，以确定进一步工作的线索。因此，该项目将加速新型脂质体和疫苗的开发。我们独特的体外试验小组经过精心挑选，与免疫反应的产生相关。一旦注射疫苗，疫苗必须吸引并激活称为抗原呈递细胞（APC）的关键免疫系统细胞。因此，我们将在体外评估APC在每种脂质体存在下的行为。我们将评估（A）APC向脂质体的迁移;（B）脂质体与APC的结合;（C）APC的脂质体活化（通常是静止的）和（D）将体外结果与已知的体内功效相关联。这种“生物标志物指纹”将在未来的工作中用于筛选体外配方库，以获得可能的体内功效。该方法将鉴定脂质体的有效体内制剂的关键生物标志物。这样做的净效果将是加快和提高疫苗开发管道的效率，对人类健康产生重大的有益影响。