Mapping fish CD4 T cell subsets for vaccine improvement

绘制鱼类 CD4 T 细胞亚群图谱以改进疫苗

• 批准号: MR/N02625X/1
• 负责人: Chris Secombes
• 金额: $ 31.42万
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FN02625X%2F1
• 关键词: Mapping; fish; CD4; cell; subsets

This project involves collaboration between two teams of experts at the University of Aberdeen and University of Santiago of Chile, conducting state-of-the-art research in complementary areas of fish immunology/fish vaccination. Aquaculture is one of the fastest growing sectors that provide food to the expanding world population. It is estimated that ~50% of fish consumed worldwide are farmed, and this figure is projected to rise. Sustainability of fish farming relies on good management of fish health and control of diseases. Vaccination is an effective strategy to control many common diseases and many highly efficacious fish vaccines exist. However, the development of fish vaccines has been largely empirical, based on whether a formulation is effective at increasing survival post-disease challenge. This is unsatisfactory from both ethical and scientific perspectives. There is a clear need to establish methods to improve fish vaccine development.This project will undertake studies to characterise an important immune pathway that may be of vital importance for future fish vaccine development. Vaccination relies on the stimulation of adaptive immunity in vertebrates, with long-term memory responses giving protection when encounter with a pathogen occurs. In mammals a key effector population driving such responses are T helper (Th) cells, that release intercellular mediators (cytokines), that initiate antimicrobial responses, including antibody production. These responses have to be tailored to the pathogen type, with viruses, parasites and extracellular bacteria requiring different immune mechanisms to give protection. Different Th subpopulations differentiate in response to these different pathogen types and host factors, and release different repertoires of cytokines to produce the most appropriate response. We know virtually nothing about these responses in fish, although many of the genes involved in mammals are now characterised or have putative homologues likely to have equivalent function. For example Th cells express CD4 on their surface, and two types of this molecule exist in teleost fish, that will likely define these cells. Here we propose to develop antibody reagents to the two CD4 molecules to detect, isolate and characterise the CD4 subsets (CD4-1+, CD4-2+, CD4-1+/CD4-2+). In immunised fish, we will study their ability to express different cytokine repertoires upon restimulation in vitro with specific antigen. Sorted CD4 cell populations will be analysed. As antigen, both a bacterial and viral protein will be used in rainbow trout, an important farmed fish in both Chile and the UK. We have developed many reagents (eg primers for immune gene expression analysis) and immune proteins (eg recombinant cytokines) for use in trout, and expect the responses to be representative of those in salmonids more generally. Following the initial experiments, we will study the effect of adding different cytokines together with the specific antigen on the ensuing responses, by analysing cytokine gene expression and CD4 subset variations. We will next select the cytokines showing the most marked effects on directing these responses to link back to confirming the involvement of CD4 (putative Th) cells. This will be done by analysing cytokine gene expression in the sorted (CD4) cell subsets following antigen restimulation in vitro in the presence of the recombinant cytokines. These results will go a long way towards confirming the function of Th cells in fish, and will establish if they can express different cytokine repertoires in response to specific antigen and cytokines. We anticipate these responses will be of value as markers of protection in future vaccine development programmes, helping to improve the efficacy of poorly performing vaccines, and to generate vaccines to emerging diseases. They may also provide an alternative means to evaluate vaccine performance, reducing the numbers of fish undergoing pathogen challenge.

该项目涉及在阿伯丁大学和智利圣地亚哥大学的两个专家团队之间的合作，并在鱼类免疫学/鱼类疫苗接种的互补领域进行了最先进的研究。水产养殖是增长最快的行业之一，为不断扩大的世界人口提供食物。据估计，在全球食用的鱼类食用鱼类中，约有50％是耕种的，这一数字预计会上升。养鱼的可持续性依赖于良好的鱼类健康和疾病控制。疫苗接种是控制许多常见疾病的有效策略，并且存在许多高效的鱼类疫苗。然而，基于表述是否有效增加生存后疾病后挑战，鱼类疫苗的开发在很大程度上是经验的。从道德和科学的角度来看，这都是不令人满意的。显然需要建立改善鱼类疫苗开发的方法。该项目将进行研究，以表征重要的免疫途径，这对于未来的鱼类疫苗开发至关重要。疫苗接种取决于脊椎动物中适应性免疫的刺激，在发生病原体时会遇到长期记忆反应。在哺乳动物中，驱动这种反应的关键效应人群是释放细胞间介质（细胞因子）的T助手（Th）细胞，它们启动抗菌反应，包括抗体产生。这些反应必须针对病原体类型量身定制，并具有病毒，寄生虫和细胞外细菌，需要不同的免疫机制才能提供保护。不同的亚群会响应这些不同的病原体类型和宿主因素，并释放细胞因子的不同曲目以产生最合适的反应。我们几乎对鱼类中的这些反应一无所知，尽管哺乳动物中涉及的许多基因现已表征或具有假定的同源物可能具有等效功能。例如，Th细胞在其表面表达CD4，而Tretost Fish中存在两种类型的该分子，这可能会定义这些细胞。在这里，我们建议开发针对两个CD4分子的抗体试剂，以检测，分离和表征CD4子集（CD4-1+，CD4-2+，CD4-1+/CD4-2+）。在免疫鱼类中，我们将研究它们在体外用特异性抗原重新刺激后表达不同细胞因子谱的能力。分类的CD4细胞群将进行分析。作为抗原，彩虹鳟鱼将使用细菌和病毒蛋白，这是智利和英国的重要养殖鱼。我们已经开发了许多试剂（例如用于免疫基因表达分析的引物）和免疫蛋白（例如重组细胞因子）用于鳟鱼，并期望这些反应更普遍地代表了鲑鱼中的反应。在初始实验之后，我们将通过分析细胞因子基因表达和CD4子集变异来研究添加不同的细胞因子以及特定抗原对随后反应的影响。接下来，我们将选择细胞因子，显示出对这些反应的最大影响，以链接回CD4（推定TH）细胞的参与。这将通过分析在重组细胞因子存在下在体外分析（CD4）细胞子集中的细胞因子基因表达来完成。这些结果将在确认TH细胞在鱼类中的功能方面有很长的路要走，并确定它们是否可以对特定的抗原和细胞因子响应不同的细胞因子库。我们预计，这些反应将作为未来疫苗开发计划中保护的标志具有价值，有助于提高性能疫苗不佳的功效，并为新兴疾病生成疫苗。他们还可以提供一种评估疫苗性能的替代方法，从而减少了受病原体挑战的鱼类数量。