Dissecting the dynamic changes in the innate immune cells of tumours to enhance immune checkpoint blockade therapies

剖析肿瘤先天免疫细胞的动态变化以增强免疫检查点阻断疗法

• 批准号: 2084493
• 金额: --
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2084493
• 关键词: Dissecting; dynamic; changes; innate; immune

AimsWe will utilise novel models of in vivo cellular migration to reveal new understanding of tumour infiltrating immune cells. Focusing on the innate immune response, we will establish a detailed order of how the innate composition of the tumour microenvironment is established and how it changes both over time and in response to different therapeutic interventions targeting T cell checkpoint mechanisms.BackgroundThe generation of photoconvertible Kaede transgenic mice where violet light can label cells at a specific site has enabled direct assessment of cellular migration in vivo [1]. We recently established an approach to temporally label all the cells within a peripheral LN and then assess cellular migration into and out of this tissue (Figure 1) [2]. Through photoconversion of a tumour draining LN or the tumour itself, we reason that TILs and other immune cells can be specifically labelled in a temporal manner providing a novel and superior means of assessing this population. Specifically, cells that had only recently entered the tissue could be distinguished and dynamic phenotypic changes after tumour entry could be determined. Furthermore, this system can then be utilised to compare dynamic changes induced by current treatments and with understanding the surface expression changes in different molecules, devise new combination strategies to enhance anti-tumour responses. Innate immune cell populations in tumours contribute to an immunosuppressiveenvironment. Several studies have identified different innate lymphoid cell (ILC) populations in tumours [3-5], but whether these cells are beneficial or suppressive is far from clear [6, 7]. Furthermore, ILC expression of molecules such as PDL1 and PD1 indicates these cells may be affected by checkpoint inhibition. Beyond ILCs, other innate immune cell populations such as MDSCs are considered key cells in limiting anti-tumour responses.HypothesisWe hypothesise that assessing dynamic changes in innate cell populations and their function within the tumour microenvironment will enhance the understanding of the mechanisms driving the effectiveness of immune checkpoint blockade therapies.Experimental Methods and Research PlanCharacterising innate cell dynamics:Initial experiments will assess the migration and retention of innate immune cells in syngeneic tumours following the injection of cell lines subcutaneously at a single site on the flank of Kaede mice. Three tumour cell lines: B16/F10, MC38 and CT26 which show differing T and innate cell infiltrations and differing responsiveness to checkpoint inhibition have been selected [8]. The inguinal LN or the tumour itself will be photoconverted (Figure 1 shows how the entire cellular compartment of a peripheral lymph node can be labelled) to track migration into and out of the tumour [1]. Standardised cell lines and validated protocols will be provided by MedImmune. We will then extend these studies to primary tumours building on existing collaborations (Awen Gallimore, Cardiff; Jessica Strid, Imperial). We will develop the use of new Dendra photoconvertible mice which show a prolonged label half-life (collaboration with Oliver Pabst, Aachen). Analysis of immune cell populations will utilise flow cytometry and immunofluorescence approaches.Checkpoint blockade therapies:Having characterised the innate immune cell infiltrates, we will then dissect the effects of checkpoint blockade strategies. Current (anti-PDL1 and/or anti-CTLA4 blockade) and novel (T cell agonists e.g.anti-OX40) approaches being developed by Medimmune will be employed providing critical new data on their effects in vivo.Expected outcomes and ImpactThe findings of the study will 1) build understanding of the dynamic changes in innate populations that contribute to an immunosuppressive tumour environment, and 2) further our understanding of how immunomodulatory therapies alter the suppressive tumour microenvironment.

我们将利用体内细胞迁移的新模型来揭示肿瘤浸润免疫细胞的新认识。关注先天免疫反应，我们将建立一个详细的顺序，肿瘤微环境的先天组成是如何建立的，以及它是如何随着时间的推移和对靶向T细胞检查点机制的不同治疗干预的反应而变化的。背景产生的可光转换的Kaede转基因小鼠，其中紫光可以标记特定部位的细胞，使得能够直接评估体内细胞迁移[1]。我们最近建立了一种方法来暂时标记外周LN内的所有细胞，然后评估细胞迁移进出该组织（图1）[2]。通过肿瘤引流LN或肿瘤本身的光转化，我们推断可以以暂时的方式特异性标记TIL和其他免疫细胞，从而提供评估该群体的新型且上级手段。具体而言，可以区分最近才进入组织的细胞，并确定肿瘤进入后的动态表型变化。此外，该系统可用于比较当前治疗诱导的动态变化，并了解不同分子的表面表达变化，设计新的组合策略以增强抗肿瘤反应。肿瘤中的天然免疫细胞群有助于形成免疫抑制环境。几项研究已经确定了肿瘤中不同的先天淋巴样细胞（ILC）群体[3 - 5]，但这些细胞是有益的还是抑制性的还远不清楚[6，7]。此外，ILC表达的分子如PDL1和PD1表明这些细胞可能受到检查点抑制的影响。除了ILC，其他先天性免疫细胞群如MDSC被认为是限制抗肿瘤反应的关键细胞。假设我们假设评估先天性细胞群的动态变化及其在肿瘤微环境中的功能将增强对驱动免疫检查点阻断疗法有效性的机制的理解。实验方法和研究计划表征先天性细胞动力学：初始实验将评估在Kaede小鼠侧腹的单个部位皮下注射细胞系后，先天免疫细胞在同系肿瘤中的迁移和保留。三种肿瘤细胞系：已经选择了B16/F10、MC 38和CT 26，它们显示出不同的T和先天细胞浸润以及对检查点抑制的不同反应性[8]。腹股沟淋巴结或肿瘤本身将被光转换（图1显示了如何标记外周淋巴结的整个细胞区室），以跟踪肿瘤的迁移进出[1]。MedImmune将提供标准化细胞系和经验证的方案。然后，我们将在现有合作的基础上将这些研究扩展到原发性肿瘤（Awen Gallimore，卡迪夫; Jessica Strid，帝国）。我们将开发使用新型Dendra光转换小鼠，其显示出延长的标记半衰期（与奥利弗帕布斯特，亚琛合作）。免疫细胞群的分析将利用流式细胞术和免疫荧光方法。检查点阻断疗法：在描述了先天免疫细胞浸润的特征后，我们将分析检查点阻断策略的效果。电流（抗PDL 1和/或抗CTLA 4阻断）和新的（T细胞激动剂，例如抗OX40）方法将被采用，该方法将提供关于其体内效应的关键新数据。预期结果和影响该研究的发现将1）建立对先天群体动态变化的理解，这些动态变化有助于免疫抑制肿瘤环境，和2）进一步理解免疫调节疗法如何改变抑制性肿瘤微环境。