CAR-T细胞治疗消化系统肿瘤的研究进展

嵌合抗原受体基因修饰T细胞（chimeric antigen receptor gene modified T lymphocyte, CAR-T cell）治疗血液肿瘤显示了良好的效果，也为治疗食管癌、胃癌、肝细胞癌、胆管癌、胰腺癌和结直肠癌等消化系统肿瘤提供了新选择。消化系统不同部位肿瘤的细胞特征和肿瘤微环境存在差异，故靶向抗原的选择和CAR-T细胞的设计也相应地有所不同。CAR-T细胞治疗与其他免疫治疗联合使用也取得了一定的进展，但主要体现在细胞实验和小鼠体内实验。目前存在的脱靶效应、细胞因子释放综合征等副作用严重阻碍了CAR-T细胞的研究进展，限制了其在实体瘤中的应用。本文就近年来CAR-T细胞治疗消化系统肿瘤的研究进展作一阐述。     

靶向肿瘤微环境的CAR-T细胞治疗结直肠癌的研究进展

结直肠癌（CRC）是最常见、致死率最高的肿瘤之一。嵌合抗原受体T（CAR-T）细胞治疗在CRC中未能重现其在血液 肿瘤和部分实体瘤治疗中获得的成功,其原因除CAR-T细胞治疗本身的研发困境（肿瘤抗原的异质性、特异性抗原的缺少等）外, CRC肿瘤微环境（TME）中存在着多重物理和生化障碍限制了T细胞抗肿瘤作用：TME复杂的脉管系统、纤维性物理屏障影响T 细胞的迁移、抑制性细胞如Treg细胞、髓源性抑制细胞（MDSC）抑制抗肿瘤免疫反应、富集的免疫抑制性细胞因子影响T细胞的 激活、肿瘤细胞通过代谢重编程影响T细胞的存活和功能等。优化CAR结构设计、构建靶向TME中免疫抑制因素的CAR-T细胞 和其他治疗手段联合治疗等策略是克服CAR-T细胞治疗应用于CRC解决低响应率的关键性思路,将为靶向TME的精准免疫治 疗深入发展提供线索和方向。     

软组织肉瘤的特异性免疫细胞治疗：困惑与希望

软组织肉瘤（soft tissue sarcoma, STS）是20岁以下人群恶性肿瘤死亡的5大原因之一，传统的治疗方法疗效不佳且患者耐受性差，而免疫治疗为攻克STS提供了新途径。STS细胞表面多种高免疫原性抗原可作为工程化T细胞的攻击靶点，过继细胞疗法（adoptive T-cell therapy，ACT）在STS中具有较大的应用潜力。靶向HER2的CAR-T细胞疗法和靶向NY-ESO-1的TCR-T细胞疗法分别在临床试验中产生了临床获益，但其疗效也受到肿瘤免疫微环境的影响。STS部分肿瘤抗原在正常组织也有表达，可被CAR-T或TCR-T细胞错误攻击而引起严重的毒副作用。为进一步增强ACT治疗STS的有效性和安全性，联合免疫检查点抑制剂的综合治疗、CAR-T设计中导入自杀基因等新治疗策略已进入STS的临床治疗。随着二代测序技术的进步，对STS各亚型免疫学性质有了更深入的研究，对免疫治疗在STS中的应用会更加“特异性”和“个体化”。     

CD19-CAR-T细胞治疗难治复发急性淋巴细胞白血病的研究进展

难治复发急性淋巴细胞白血病（acute lymphocytic leukemia, ALL）预后差,生存期短,其治疗已成为国际难题。嵌合抗原受体基因修饰T（chimeric antigen receptor gene-modified T,CAR-T）细胞是目前最具应用前景的靶向免疫治疗,靶向CD19的CAR-T细胞（CD19-CAR-T）治疗儿童及成人难治复发性ALL的完全缓解率（complete remission,CR）可达90%以上,疗效远高于化疗。然而,细胞因子释放综合征（cytokine release syndrome,CRS）、严重神经毒性（serious neurotoxicity,SNT）、脱靶效应以及疾病复发等严重限制了CAR-T细胞的进一步临床应用。本文主要阐述CAR-T细胞的制备技术、预处理方案、细胞输注剂量及各种并发症防治策略等最新研究进展。     

嵌合抗原受体基因修饰T淋巴细胞治疗肺癌的研究进展和挑战

近年来,免疫疗法尤其是单克隆抗体靶向药物越来越多地应用于肺癌的临床治疗,但仍有很多局限性。嵌合抗原受体基因修饰T淋巴细（chimeric antigen receptor gene modified-T lymphocytes,CAR-T）疗法对于部分B细胞淋巴瘤和白血病的疗效显著,也为实体瘤的疫治疗开辟了新途径。肺癌CAR-T疗法的热门靶点包括间皮素（MSLN）、黏蛋白突变体（TnMUC1）、表皮生长因子受体（EGFR）、人皮生长因子受体2（HER2）、受体酪氨酸激酶样孤儿受体1（ROR1）和δ样配体3（DLL3）等,但相关临床研究均处于早期探索阶段。所面的主要障碍包括脱靶毒性、肿瘤免疫抑制微环境和CAR-T细胞体内效能不足等。通过基因编辑改进CAR结构、设计多靶点CAR或组合应用多点CAR-T细胞、精细调控CAR-T细胞体内动态分布、改进给药方式或联合其他免疫治疗等策略可能有助于解决这些问题。     

过继性T细胞治疗在非小细胞肺癌中的研究进展

T细胞是获得性抗肿瘤免疫的重要细胞亚群,但肿瘤组织中的T细胞数量少,且处于免疫抑制甚至耗竭状态,这是导致肿瘤免疫逃逸和免疫检查点抑制剂等抗肿瘤免疫治疗效果不佳的重要原因。过继性T细胞治疗主要包括肿瘤浸润淋巴细胞（tumor-infiltrating lymphocytes,TILs）、嵌合抗原受体T细胞（chimeric antigen receptor T-cell,CAR-T）、T细胞受体工程化T细胞（T-cell receptor engineering T cell,TCR-T）治疗,其通过体外筛选扩增富集肿瘤特异性T细胞或通过基因改造赋予T细胞新的抗原特异性（CAR-T、TCR-T）,有效克服了肿瘤浸润T细胞不足的缺陷。虽然过继性T细胞治疗在非小细胞肺癌（non-small cell lung cancer,NSCLC）中的研究起步较晚,但已显示治疗的安全可行性和初步抗肿瘤效果,值得进一步深入研究。本文将对TILs、CAR-T、TCR-T的原理、培养方法、生物学特征以及在NSCLC治疗中的研究进展进行综述,以期为优化临床研究设计和开展新型NSCLC免疫治疗提供新思路。      

免疫检查点分子联合CAR-T细胞治疗实体肿瘤研究进展

免疫检查点分子是一组表达于免疫细胞表面,主要调控免疫细胞稳态的分子。嵌合抗原受体修饰的T细胞（CAR-T）免疫疗法是通过生物技术构建表达特异性抗原的人工合成T细胞,实现肿瘤靶向杀伤的免疫治疗技术。CAR-T治疗策略已在血液肿瘤临床治疗中取得了较好的疗效,但针对实体肿瘤的CAR-T免疫治疗技术有待进一步研究完善。本文就免疫检查点分子联用CAR-T免疫疗法在实体肿瘤治疗中面临的问题及新进展进行综述。     

嵌合抗原受体修饰T细胞治疗实体肿瘤研究进展

嵌合抗原受体修饰T细胞(chimeric antigen receptor T cell,CAR-T)是指通过基因工程技术构建载体转移到T细胞,使T细胞表面表达特定的抗原受体,以此来识别靶细胞上特异性抗原并激活T细胞,从而发挥抗肿瘤作用。CAR-T细胞在治疗血液系统恶性肿瘤方面的研究开展较早,并取得了显著疗效,在实体肿瘤方面,由于肿瘤基质的屏障以及肿瘤免疫抑制微环境的作用,CAR-T细胞在实体肿瘤临床应用方面的研究进展缓慢。本文就CAR-T细胞应用于实体肿瘤治疗的最新研究进展作一综述。     

T淋巴细胞归巢：实体肿瘤过继性细胞治疗的关键因素

近年来,肿瘤免疫治疗迅速发展,其中以T淋巴细胞（T细胞）为主体的过继细胞治疗在临床上取得了一定的疗效,成为最具潜力的免疫治疗方法之一。T细胞归巢主要包括滚动、黏附、外渗和趋化等一系列过程。然而,在实体瘤中存在物理屏障、趋化因子不匹配、血管异常、免疫抑制微环境等因素限制了过继性细胞治疗的疗效。通过改善细胞表面的趋化因子受体、嵌插靶向肽、改进给药方式以及采用联合放疗、免疫检查点阻断剂、肿瘤疫苗、双特异性抗体等治疗方法,可进一步改善T细胞的归巢能力。本文主要对T细胞归巢过程、T细胞靶向肿瘤部位的影响因素以及相关治疗策略做总结与展望。     

嵌合抗原受体修饰的免疫细胞及其在肿瘤免疫治疗中的应用

嵌合抗原受体修饰的T（chimeric antigen receptor-modified T,CAR-T）细胞是指通过基因修饰技术将带有特异性抗原 识别结构域及T细胞激活信号的遗传物质转入T细胞并表达,使T细胞能直接与肿瘤细胞表面的特异性抗原相结合而被激活的 细胞疗法。近年来,CAR-T细胞在血液病治疗中取得了显著的效果,为血液肿瘤患者带来了新的希望,已成为最有希望的肿瘤免 疫治疗方法之一,成为各大企业研发的热点。但是由于CAR-T细胞疗法会产生细胞因子风暴等不良反应及对实体瘤的治疗效果 不佳,使得CAR-T细胞的临床应用仍面临挑战。除T细胞之外,研究人员正在探讨将CAR运用到其他免疫细胞上,例如对NK细 胞、γδT细胞、NKT细胞、巨噬细胞等免疫细胞进行修饰,以提高这些免疫细胞杀伤肿瘤的效果,同时降低CAR-T细胞免疫治疗所 带来的不良反应。本文通过比较CAR修饰不同的免疫细胞在肿瘤治疗中的优点和缺点,为CAR修饰免疫细胞在肿瘤免疫治疗 中的临床开发和应用提供新的思路和启示。     

CAR-T疗法在治疗肿瘤免疫逃逸中的研究进展

机体内的免疫系统可以对肿瘤细胞产生免疫应答从而进一步消除肿瘤。但部分肿瘤能在宿主体内生长、转移和突变,表明其具有免疫逃逸的能力。肿瘤细胞抗原本身发生逃逸、效应细胞功能强弱、肿瘤细胞微环境等都与肿瘤的免疫逃逸密切相关。近年来,以嵌合抗原受体T（CAR-T）细胞疗法为主的免疫疗法在肿瘤的治疗领域发展迅猛,正逐渐成为治疗肿瘤的主流方向,本文对治疗肿瘤免疫逃逸中CAR-T的应对治疗策略和进展进行梳理,旨在为CAR-T疗法治疗肿瘤的下一步发展优化思路。     

CD276 suppresses CAR-T cell function by promoting tumor cell glycolysis in esophageal squamous cell carcinoma

BackgroundAs an immune checkpoint that suppresses antitumor immunity, CD276 is a potential therapeutic target for cancer immunotherapy. However, the role of CD276 in esophageal squamous cell carcinoma (ESCC) has not been thoroughly examined. A greater understanding of the regulatory mechanism of CD276 may improve the clinical response and efficacy of cancer immunotherapy.MethodsThe expression of CD276 was measured by qRT-PCR, IHC and flow cytometry analysis. T cell infiltration in ESCC was measured by qRT-PCR and immunofluorescence analysis. The regulation function of CD276 in glucose metabolism was examined by metabolism assays, western blotting and small molecule inhibitors. Transfection was used for gene editing. The oncogenic function of CD276 was examined in vivo by CAR-T cell therapy model.ResultsBased on our findings, CD276 regulated the expression of the PKM2 gene in ESCC. Overexpression of CD276 induced the phosphorylation of PKM2 by the STAT3 signalling pathway to promote glucose metabolism in tumors. The accumulation of lactic acid in the tumor microenvironment has been reported to regulate the immune cells, particularly CD8+ T cells. We further analyzed the effect of CD276 on the function of T cells. Chimeric antigen receptor T cells (CAR-T) targeting human epidermal growth factor receptor 2 (HER2) were used as effector cells to detect the effect of CD276 on immunotherapy. The therapeutic effects of CAR-T cells were markedly limited by CD276 overexpression.ConclusionsOur results are the first to show that tumor-derived CD276 supports disease progression. Overexpression of CD276 promoted glucose metabolism in tumor and inhibited the function of CD8+ T cells. Therefore, strategies targeting CD276 might improve the response to cancer immunotherapy of ESCC patients.     

用于实体瘤治疗的缺氧敏感型CAR-T细胞的研究进展

嵌合抗原受体T(chimeric antigen receptor T,CAR-T)细胞治疗作为一种肿瘤免疫疗法已经在血液系统肿瘤的临床治疗中取得良好效果。然而,由于实体瘤缺乏肿瘤特异性抗原,大多数CAR-T细胞以同样在机体其他正常组织器官中广泛表达的肿瘤相关抗原作为识别靶点,导致脱靶效应的产生,严重时甚至会危及患者生命。由于脱靶效应的存在,CAR-T细胞治疗在实体瘤治疗领域中的应用受到严重限制。为克服CAR-T细胞治疗中脱靶效应的影响,可以利用肿瘤微环境中氧含量低的特点,设计缺氧敏感型CAR-T细胞,使其仅在乏氧的肿瘤微环境中表达靶向肿瘤相关抗原的CAR,从而避免CAR-T细胞对正常组织器官的“误伤”。本文综述缺氧敏感型CAR-T细胞构建的常用元件和思路,梳理近年来构建缺氧敏感型CAR-T细胞的研究进展,有望加强CAR-T细胞治疗的安全性,提高CAR-T细胞在实体瘤治疗中的效果。     

骨髓源性抑制细胞在肿瘤免疫治疗中的研究进展及与肺癌预后的关系

免疫治疗是肺癌新兴治疗方法,其疗效受肿瘤免疫微环境（tumor immune microenvironment,TIME）影响。骨髓源性抑制细胞(myeloid-derived suppressor cells,MDSCs)是免疫微环境的主要免疫抑制细胞,在肿瘤的发生、发展、侵袭和转移过程中起关键作用。近年来,探索克服MDSCs的免疫抑制,从而增强抗肿瘤治疗疗效的研究已经成为研究热点。在这篇综述中,我们讨论了靶向MDSCs以及与ICI联合治疗的进展,并总结了MDSCs对肺癌患者预后的影响。     

Immunotherapy for lung cancer: Focusing on chimeric antigen receptor (CAR)-T cell therapy

Besides traditional treatment strategies, including surgery, radiotherapy, and chemotherapy for lung cancer as the leading cause of cancer incidence and death, immunotherapy has also emerged as a new treatment strategy. The goal of immunotherapy is to stimulate the immune system responses against cancer, using various approaches such as therapeutic vaccines, monoclonal antibodies, immune checkpoint inhibitors, and T-cell therapy. Chimeric antigen receptor (CAR)-T cells, one of the most popular cancer immunotherapy approaches in the last decade, are genetically engineered T-cells to redirect patients' immune responses to recognize and eliminate tumor-associated antigens (TAA)-expressing tumor cells. CAR-T cell therapy provides promising benefits in lung tumors. In this review, we summarize different immunotherapy approaches for lung cancer, the structure of CAR-T cells, currently undergoing CARs in clinical trials, and various TAAs are being investigated as potential targets in designing CAR-T cells for lung cancer.     

CAR-T细胞免疫治疗肿瘤的毒副反应及临床对策

嵌合抗原受体T细胞(chimeric antigen receptorT cell,CAR-T)是肿瘤免疫治疗的重要手段,具有较强的抗肿瘤活性,但临床毒副反应明显.CAR-T细胞可通过识别共表达靶抗原及交叉抗原的组织等机制,引起肿瘤溶解综合征(tumor lysis syndrome,TLS)和细胞因子释放综合征(cytokine release syndrome,CRS)等全身性损伤.有效监测和及时处理是防治毒副反应的关键,本文结合多个CAR-T细胞治疗肿瘤临床研究的结果与经验,对CAR-T细胞治疗肿瘤的相关毒副反应及临床对策作一阐述.     

CAR-T细胞治疗实体肿瘤的新策略

[摘要] 嵌合型抗原受体修饰T(chimeric antigen receptor modified T,CAR-T)细胞治疗作为一种新的过继性免疫疗法在血液肿瘤中已取得了较好的疗效。在实体肿瘤中,肿瘤微环境中存在大量免疫抑制细胞、免疫抑制分子以及胞外基质,对迁移的CAR-T细胞的细胞毒性效应产生抑制作用,在实体肿瘤内严重抑制CAR-T细胞的抗肿瘤效力。同时,大多数实体肿瘤存在肿瘤异质性且缺乏相对特异性肿瘤抗原,CAR-T细胞在实体肿瘤部位的归巢能力差并伴随着脱靶效应,使其在实体瘤中的疗效欠佳。与血液肿瘤相比,实体瘤具有复杂的生物学特性,需要针对性的策略才能保证CAR-T细胞抗肿瘤长期有效。本文就CAR-T 细胞的发展、在实体瘤治疗中的困惑及治疗策略的研究进展作一阐述。     

CAR-T在胃癌免疫治疗中的研究进展

胃癌是最常见的恶性肿瘤之一,部分病例由于诊断较晚和治疗不佳,患者的整体生存期较差。近几年,嵌合抗原受体修饰T细胞（chimeric antigen receptor T cells,CAR-T）疗法在肿瘤治疗研究领域受到相当大的关注,且已在血液系统肿瘤中发挥了重要作用,但在实体肿瘤因受到靶点特异性,肿瘤微环境等因素影响而作用受限。尽管如此,各种临床前和临床实验已证实CAR-T细胞免疫治疗是胃癌一种有前景的治疗方法,并具有有别于其他实体瘤的优势,但是仍面临诸多挑战。本文将系统介绍CAR-T疗法在胃癌中的最新研究进展。      

Cancer‐associated fibroblast‐targeted strategy enhances antitumor immune responses in dendritic cell‐based vaccine

Given the close interaction between tumor cells and stromal cells in the tumor microenvironment (TME), TME‐targeted strategies would be promising for developing integrated cancer immunotherapy. Cancer‐associated fibroblasts (CAFs) are the dominant stromal component, playing critical roles in generation of the pro‐tumorigenic TME. We focused on the immunosuppressive trait of CAFs, and systematically explored the alteration of tumor‐associated immune responses by CAF‐targeted therapy. C57BL/6 mice s.c. bearing syngeneic E.G7 lymphoma, LLC1 Lewis lung cancer, or B16F1 melanoma were treated with an anti‐fibrotic agent, tranilast, to inhibit CAF function. The infiltration of immune suppressor cell types, including regulatory T cells and myeloid‐derived suppressor cells, in the TME was effectively decreased through reduction of stromal cell‐derived factor‐1, prostaglandin E₂, and transforming growth factor‐β. In tumor‐draining lymph nodes, these immune suppressor cell types were significantly decreased, leading to activation of tumor‐associated antigen‐specific CD8⁺ T cells. In addition, CAF‐targeted therapy synergistically enhanced multiple types of systemic antitumor immune responses such as the cytotoxic CD8⁺ T cell response, natural killer activity, and antitumor humoral immunity in combination with dendritic cell‐based vaccines; however, the suppressive effect on tumor growth was not observed in tumor‐bearing SCID mice. These data indicate that systemic antitumor immune responses by various immunologic cell types are required to bring out the efficacy of CAF‐targeted therapy, and these effects are enhanced when combined with effector‐stimulatory immunotherapy such as dendritic cell‐based vaccines. Our mouse model provides a novel rationale with TME‐targeted strategy for the development of cell‐based cancer immunotherapy.     

Challenges and prospects of chimeric antigen receptor T cell therapy in solid tumors

Chimeric antigen receptor (CAR) T cell therapy is a novel and innovative immunotherapy. CAR-T cells are genetically engineered T cells, carrying MHC independent specific antigen receptor and co-stimulatory molecule which can activate an immune response to a cancer specific antigen. This therapy showed great results in hematological malignancies but were unable to prove their worth in solid tumors. Likely reasons for their failure are lack of antigens, poor trafficking, and hostile tumor microenvironment. Excessive amount of research is going on to improve the efficacy of CAR T cell therapy in solid tumors. In this article, we will discuss the challenges faced in improving the outcome of CAR T cell therapy in solid tumors and various strategies adopted to curb them.