Characterisation of porcine T follicular helper cells and their response to vaccination and infection

猪滤泡辅助 T 细胞的特征及其对疫苗接种和感染的反应

• 批准号: 2748526
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2748526
• 关键词: Characterisation; porcine; follicular; helper; cells

Since they were first discovered in 2000, the function of T follicular helper (Tfh) cells has been a subject of intense and fast-moving research. It is now clear that these cells are critical in orchestrating the B cell/antibody response and they have become a focus in improving targeted cancer immunotherapy and vaccine strategies. In humans and mice, Tfh are characterised by expression of CXC chemokine receptor 5 (CXCR5), inducible T cell costimulatory (ICOS), programmed cell death protein 1 (PD-1), T-cell lymphoma 6 (Bcl-6) and interleukin 21 (IL-21). It is now clear that at least five phenotypes exist across secondary lymphoid tissues and in circulation, each prevalent at different stages of the immune response and each expressing different levels of the archetypal Tfh phenotypic markers. Notably, in both SARS-CoV-2 and HIV infection an increased frequency of circulating Tfh correlates with decreased disease severity and enhanced neutralising antibody responses, respectively.There are limited studies on Tfh cells in the pig, which is both a major food producing species and an important biomedical model. This project therefore intends to expand our knowledge of the phenotype and function of porcine Tfh cells. We have demonstrated cross-species reactivity of several Tfh markers, including Bcl-6 and ICOS, and in collaboration with the Roslin Institute, developed a reagent for labelling of CXCR5-expressing cells. The first aim of the project is to furtherdevelop and optimise staining panels for both flow cytometry and confocal microscopy applications to identify and characterise porcine Tfh in blood and secondary lymphoid organs. Defined Tfh-like populations will be cell sorted and assessed in functional assays involving assessment of antibody production from co-cultured syngeneic B cells. Sorted cells will be further characterised by RNAseq transcriptomic analysis. Funding permitting, a spatial transcriptomic analysis, whereby the spatial location of each cell is determined and accounted for, may be performed on lymphoid organ sections. Finally, the tools developed will be applied in the context of vaccination and infection. For example, assessing the frequency and phenotype of circulating and tissue resident Tfh during infection with the porcine reproductive and respiratory syndrome virus (PRRSV). Tfh response profiles will be compared to CXCL13, IL-21 and IL-6 levels in serum, virus loads in blood and tissues and neutralising antibody responses to determine whether associations exist.

自 2000 年首次发现以来，滤泡辅助 T (Tfh) 细胞的功能一直是密集且快速发展的研究课题。现在很清楚，这些细胞在协调 B 细胞/抗体反应中至关重要，它们已成为改善靶向癌症免疫治疗和疫苗策略的焦点。在人和小鼠中，Tfh 的特征是表达 CXC 趋化因子受体 5 (CXCR5)、诱导型 T 细胞共刺激 (ICOS)、程序性细胞死亡蛋白 1 (PD-1)、T 细胞淋巴瘤 6 (Bcl-6) 和白细胞介素 21 (IL-21)。现在已经清楚，次级淋巴组织和循环中至少存在五种表型，每种表型普遍存在于免疫反应的不同阶段，并且每种表型表达不同水平的原型 Tfh 表型标记物。值得注意的是，在 SARS-CoV-2 和 HIV 感染中，循环 Tfh 频率的增加分别与疾病严重程度的降低和中和抗体反应的增强相关。对猪中 Tfh 细胞的研究有限，猪既是主要的粮食生产物种，也是重要的生物医学模型。因此，该项目旨在扩展我们对猪 Tfh 细胞表型和功能的了解。我们已经证明了多种 Tfh 标记物（包括 Bcl-6 和 ICOS）的跨物种反应性，并与罗斯林研究所合作开发了一种用于标记 CXCR5 表达细胞的试剂。该项目的首要目标是进一步开发和优化流式细胞术和共聚焦显微镜应用的染色组，以识别和表征猪血液和次级淋巴器官中的 Tfh。确定的 Tfh 样群体将在功能测定中进行细胞分选和评估，包括评估共培养的同基因 B 细胞的抗体产生。分选的细胞将通过 RNAseq 转录组分析进一步表征。如果资金允许，可以在淋巴器官切片上进行空间转录组分析，从而确定和解释每个细胞的空间位置。最后，开发的工具将应用于疫苗接种和感染领域。例如，评估猪繁殖与呼吸综合征病毒 (PRRSV) 感染期间循环和组织驻留 Tfh 的频率和表型。将 Tfh 反应谱与血清中的 CXCL13、IL-21 和 IL-6 水平、血液和组织中的病毒载量以及中和抗体反应进行比较，以确定是否存在关联。