Manipulating cholangiocarcinoma immune-phenotype in a patient derived precisioncut tumour model to improve immune checkpoint inhibition response.

胆管细胞癌(CCA)是一种侵袭性肿瘤，其发病率和死亡率在全球范围内呈上升趋势。患者预后仍然很差，免疫检查点阻断(ICB)等免疫治疗方法与传统化疗相结合显示出只有一小部分患者有显著好处。为了更好地了解治疗反应/耐药的机制，有必要进一步研究CCA中的肿瘤微环境(TME)。ICB介导的抗肿瘤反应依赖于细胞毒性T细胞靶向和破坏肿瘤细胞的功能。免疫‘热’瘤的CD8+T细胞浸润增加，从而改善了ICB治疗反应，而免疫‘冷’瘤的细胞毒性T细胞渗透减少，免疫抑制免疫细胞(如肿瘤相关巨噬细胞和T-调节细胞)水平较高。ICB治疗的不良反应表明许多CCA肿瘤具有‘冷’免疫表型。将肿瘤免疫表型从“冷”调整为“热”的组合策略可以显著提高ICB的临床有效性，并且在CCA研究中仍是一个未被探索的领域。该项目的主要目的是评估人患者来源的CCA精密切割组织切片(HPCTS)作为体外模型，以探索增加TME的方法，确定对免疫治疗的反应/抵抗，并测试新的联合疗法。该项目的第一个目标将是增强CCA TME，并通过药物抑制免疫抑制细胞类型，如肿瘤相关巨噬细胞和髓系来源的抑制细胞，在CCA hPCTS中建立免疫“热”表型。下一步将是确定免疫‘热’PCTS TME是否通过将免疫‘热’暴露于ICB抑制剂来增加ICB反应，并将其作为单一疗法或与常规化疗联合使用，并评估其生存能力。最后，将通过原位数字空间图谱建立对ICB应答/耐药的免疫蛋白质组预测生物标记物。总体而言，该项目旨在增强CCA hPCTS TME并评估对各种免疫治疗/化疗方案的反应/耐药性，这可能会改善CCA患者的ICB反应。同时，这项工作将进一步探索免疫治疗的反应/耐药机制，并识别相应的预测生物标志物。人们希望，这种模式最终也将取代免疫肿瘤学领域对动物实验的需求，这些实验成本高昂，引发伦理担忧，而且无法完全概括人类的TME和人类疾病。

Cholangiocarcinoma (CCA) is an aggressive cancer type, and its incidence and mortality are increasing globally. Patient prognosis remains poor, with immunotherapeutic approaches such as immune-checkpoint blockade (ICB) in combination with conventional chemotherapy showing a significant benefit in only a small proportion of patients. Further work looking into the tumour microenvironment (TME) in CCA is necessary in order to better understand the mechanisms of therapy response/ resistance. ICB-mediated anti-tumour responses rely on the function of cytotoxic T-cells to target and destroy tumour cells. Immune 'hot' tumours have increased CD8+T-cell infiltration and, thus, improved ICB therapy response, whereas, immune 'cold' tumours show reduced cytotoxic T-cell infiltration and have high levels of immunosuppressive immune cells (e.g. tumour-associated macrophages and T-regulatory cells). The poor response to ICB therapy suggests many CCA tumours have a 'cold' immune phenotype. Combination strategies that modulate tumour immune-phenotype from 'cold' to 'hot' could significantly increase ICB clinical-effectiveness and remains an underexplored area in CCA research. The main aim of this project is to evaluate human patient-derived CCA precision-cut tissue slices (hPCTS) as an ex-vivo model to investigate approaches to augment the TME, determine response/ resistance to immunotherapy and test novel combination therapies. The first objective of the project will be to augment the CCA TME and establish an immune 'hot' phenotype in CCA hPCTS through pharmacological inhibition of immunosuppressive cell types such as tumour-associated macrophages and myeloid-derived suppressor cells. The next step will be to determine whether an immune 'hot' PCTS TME increases ICB response by exposing immune 'hot' and control hPCTS to ICB inhibitors as monotherapy or in combination with conventional chemotherapy and assessing their viability. Finally, immunoproteomic predictive biomarkers of response/ resistance to ICB will be established through in situ digital spatial profiling. Overall, this project aims to augment the CCA hPCTS TME and assess responses/ resistance to various immunotherapeutic/ chemotherapeutic regimes, which has potential to improve ICB response in CCA patients. Simultaneously, this work will further the exploration of immunotherapy response/ resistance mechanisms and the identification of corresponding predictive biomarkers. The hope is that this model will also eventually replace the need for animal experiments in this field of immuno-oncology, which are expensive, raise ethical concerns, and are unable to fully recapitulate the human TME and human disease.