Supporting data for PhD thesis "Development of Cancer Immunotherapeutic Strategies Based on Multi-Dimensional Understanding of Cancer Immunology"

The field of cancer immunotherapy has experienced significant advancements, particularly with the development of innovative therapies. These include cancer neoantigen vaccines that stimulate systemic tumor-specific immune responses, immune checkpoint inhibitors (ICIs) that revitalize tumor-specific immune cells, chimeric antigen receptor T-cell (CAR-T) therapy that introduces large numbers of tumor-specific T cells for effective eradication, and antibody-based treatments that enable targeted attacks. Despite these significant developments, the effectiveness of these therapies is often limited by tumor-induced immunosuppression and resistance within the tumor microenvironment (TME). Furthermore, cancer is increasingly recognized as a systemic disease characterized by immune status alterations throughout the body, underscoring the imperative for therapies that address both systemic and intratumoral immune activation.This study explores novel cancer therapeutic strategies through a comprehensive understanding of cancer immunology. Initially, we developed and optimized a neoantigen vaccine-based therapeutic strategy aimed at systemically activating tumor-specific immune responses and improving the TME. This was achieved by combining α-Galactosylceramide (α-GalCer) to activate invariant natural killer T (iNKT) cells, which resulted in improved treatment outcomes. Although this approach successfully reversed inhibitory immune cells, it was insufficient to overcome tumor heterogeneity. To address this, we introduced allogeneic major histocompatibility complex (MHC) molecules within tumors to label them, thereby enhancing their recognizability and addressing heterogeneity. However, this strategy did not adequately activate the corresponding systemic immune response, impacting overall efficacy.To overcome these limitations, we further refined our strategy to concurrently activate systemic and intratumoral immunity. Our research demonstrated that incorporating a systemic immunity activation step against the same allogeneic MHC significantly improved therapeutic outcomes. To enhance efficacy further, we replaced the allogeneic MHC with pathogen-derived antigens, which increased the antigenicity and immunogenicity of the tumor. Our data showed that using an mRNA vaccine platform to establish a systemic anti-pathogen antigen immune response, followed by the introduction of the same antigen within the tumor, effectively marked tumor cells with pathogen antigen proteins. This rapidly activated a systemic pathogen antigen-specific immune response, leading to the elimination of marked tumor cells. The subsequent eradication of these cells triggered antigen spreading, inducing a broader tumor-specific immune response against heterogeneous tumor cells.This strategy effectively combines systemic and intratumoral immune activation while improving the TME and overcoming tumor heterogeneity. Consequently, this pathogen antigen mRNA vaccine-based cancer immunotherapy shows promise as a potent, broad-spectrum, off-the-shelf treatment. It offers the potential to achieve multiple cancer treatment goals with a single drug, paving the way for future combinational therapies. Given that a large portion of the global population has developed immune memory against various pathogens through infection or vaccination—particularly SARS-CoV-2—we predict that mRNA lipid nanoparticle-based vaccines targeting pathogens such as SARS-CoV-2, Hepatitis B Virus (HBV), Common Human Coronaviruses (HCoVs), and the influenza virus could provide a comprehensive immunotherapy strategy for various cancers. The extensive selection of pathogen antigens broadens therapeutic opportunities and reduces the risk of drug resistance. We believe this therapeutic approach could rapidly transition into clinical use, offering a promising alternative for cancer patients and setting the stage for future combinational treatments.

癌症免疫治疗领域经历了显著的进步，尤其是在创新疗法的研发方面。这些疗法包括能够激发全身肿瘤特异性免疫反应的癌症新抗原疫苗，能够复活肿瘤特异性免疫细胞的免疫检查点抑制剂（ICIs），以及通过引入大量肿瘤特异性T细胞实现有效清除的嵌合抗原受体T细胞（CAR-T）疗法，还有基于抗体的治疗，能够实现精准打击。尽管这些疗法取得了显著的进展，但它们的有效性往往受到肿瘤诱导的免疫抑制和肿瘤微环境（TME）内耐药性的限制。此外，癌症越来越被视为一种全身性疾病，其特征是全身免疫状态的改变，这凸显了治疗策略同时解决全身和肿瘤内免疫激活的必要性。本研究通过全面理解癌症免疫学，探索了新颖的癌症治疗策略。最初，我们开发并优化了一种基于新抗原疫苗的治疗策略，旨在全身激活肿瘤特异性免疫反应并改善TME。这是通过结合α-半乳糖基神经酰胺（α-GalCer）以激活不变性自然杀伤T细胞（iNKT细胞）实现的，从而改善了治疗结果。尽管这种方法成功地逆转了抑制性免疫细胞，但不足以克服肿瘤异质性。为了解决这个问题，我们在肿瘤内引入了同种异体主要组织相容性复合体（MHC）分子以标记它们，从而增强了它们的可识别性并解决了异质性。然而，这一策略并未充分激活相应的全身免疫反应，影响了整体疗效。为了克服这些限制，我们进一步优化了策略，以同时激活全身和肿瘤内免疫。我们的研究证明了，针对相同同种异体MHC的全身免疫激活步骤的引入显著提高了治疗效果。为了进一步提高疗效，我们将同种异体MHC替换为病原体来源的抗原，从而增加了肿瘤的抗原性和免疫原性。我们的数据显示，使用mRNA疫苗平台建立针对病原体抗原的全身免疫反应，随后在肿瘤内引入相同的抗原，有效地用病原体抗原蛋白标记了肿瘤细胞。这迅速激活了针对病原体抗原的全身特异性免疫反应，导致标记的肿瘤细胞被清除。这些细胞的清除触发了抗原扩散，诱导了对异质性肿瘤细胞更广泛的肿瘤特异性免疫反应。这一策略有效地结合了全身和肿瘤内免疫激活，改善了TME并克服了肿瘤异质性。因此，基于病原体抗原mRNA疫苗的癌症免疫疗法显示出作为高效、广谱、现成治疗的潜力。它有望通过单一药物实现多种癌症治疗目标，为未来的联合治疗铺平道路。鉴于全球大量人口通过感染或疫苗接种已经对各种病原体产生了免疫记忆——特别是SARS-CoV-2——我们预测，针对SARS-CoV-2、乙型肝炎病毒（HBV）、普通人类冠状病毒（HCoVs）和流感病毒的mRNA脂质纳米颗粒疫苗可以作为各种癌症的综合免疫治疗策略。病原体抗原的广泛选择扩大了治疗机会并降低了药物耐药性的风险。我们相信这种治疗策略可以迅速转化为临床应用，为癌症患者提供一种有希望的替代方案，并为未来的联合治疗奠定基础。