肿瘤细胞治疗研究
英文原题：Intrinsic tumor cell line immunogenicity may drive CAR-independent T cell responses and confound CAR T cell preclinical modeling.
这些发现表明，某些肿瘤细胞系能够引发强烈的同种异体T细胞反应，且不依赖于CAR特异性，揭示了常用临床前模型的一个重要局限性，并凸显了CAR T细胞疗效评估中出现假阳性的可能性。
**背景：**靶向 CD19 的嵌合抗原受体（CAR）T 细胞是美国食品药品监督管理局（FDA）批准用于多种血液系统恶性肿瘤的高效疗法。然而，受耐药、抗原调节、全身毒性和复发影响，其疗效仍存在差异。开发更优 CAR-T 疗法依赖能够准确预测临床结局的临床前模型；为此常使用 Raji 伯基特淋巴瘤细胞系等永生化肿瘤细胞系。**方法：**将靶向 CD19 的 CAR（CAR19）及未转导（NT）人 T 细胞与靶细胞系体外共培养，评估 T 细胞细胞毒性、细胞因子产生、活化和增殖。采用主要组织相容性复合体（MHC）I 类和 II 类阻断抗体及 TCR 敲除（KO）T 细胞验证 TCR 相互作用。体内实验中，以 CAR19 或 NT T 细胞治疗携带 Raji 野生型（WT）或 CD19 KO 肿瘤的小鼠，并分析生存、肿瘤负荷、血清细胞因子和组织中的 T 细胞表型。统计分析采用 GraphPad Prism 9 完成，包括配对/配对比值/非配对双侧 Student t 检验、双因素方差分析及 log-rank（Mantel-Cox）检验。**结果：**来自多个不同供者的 T 细胞不仅可对表达 CD19 的 Raji WT 细胞产生强烈 CAR 介导的细胞毒性，出乎意料的是，也会对 Raji CD19 KO 细胞产生 CAR 非依赖性反应。该反应在体内外均可观察到，并伴随促炎细胞因子分泌及 T 细胞活化标志上调，符合内源性 TCR 被激活的特征。NT T 细胞对 Raji 细胞也表现出类似的活化、细胞毒性和细胞因子应答。体外实验中，其他 B 细胞白血病/淋巴瘤或实体瘤细胞系未引发此类效应。CD4⁺和 CD8⁺ T 细胞群均参与该同种异体反应；阻断 MHC I 类或 II 类分子可减弱反应，提示其依赖 TCR-MHC 机制。**结论：**某些肿瘤细胞系可在不依赖 CAR 特异性的情况下引发强烈同种异体 T 细胞反应，这揭示常用临床前模型的一项重要局限，并提示可能错误高估 CAR-T 疗效。临床前测试前应验证肿瘤模型是否存在同种异体反应。
BACKGROUND: Chimeric antigen receptor (CAR) T cells are highly potent therapies approved by the U.S. Food and Drug Administration (FDA) for several hematological malignancies. However, efficacy remains variable due to resistance, antigen modulation, systemic toxicities, and relapse. Developing improved CAR T cell therapies relies on preclinical models that accurately predict clinical outcomes. For this purpose, immortalized tumor cell lines, such as the Burkitt's lymphoma line Raji, are commonly used. METHODS: CD19-targeting CAR (CAR19) and non-transduced (NT) human T cells were co-cultured with target cell lines in vitro to assess T cell cytotoxicity, cytokine production, activation, and proliferation. Major histocompatibility complex (MHC) class I and II blocking antibodies and TCR knockout (KO) T cells were used to validate T cell receptor interactions. In vivo, Raji wild-type (wt) or CD19 KO tumor-bearing mice were treated with CAR19 or NT T cells, and survival, tumor burden, serum cytokines, and T cell phenotype in tissues were analyzed. Statistical analyses using either paired/paired ratio/unpaired two-tailed Student's t tests, two-way analysis of variance, and log-rank (Mantel-Cox) tests were performed using GraphPad Prism 9. RESULTS: We report that T cells generated from multiple different donors exhibit not only strong CAR-mediated cytotoxicity against CD19-expressing Raji WT cells but also, unexpectedly, CAR-independent reactivity against Raji CD19 KO cells. This reactivity was observed both in vitro and in vivo, and was associated with pro-inflammatory cytokine secretion and upregulation of T cell activation markers, consistent with endogenous T cell receptor (TCR) engagement. NT T cells displayed similar activation, cytotoxic, and cytokine responses against Raji cells. These effects failed to occur using other B cell leukemia/lymphoma or solid tumor cell lines in vitro. Both CD4+ and CD8+ T cell populations contributed to this alloreactive response, which could be attenuated by blockade of MHC class I or II, highlighting a TCR:MHC-dependent mechanism. CONCLUSIONS: These findings demonstrate that certain tumor lines can elicit strong allogeneic T cell responses independent of CAR specificity, revealing an important limitation of commonly used preclinical models and highlighting the potential for false-positive assessments of CAR T cell efficacy. Furthermore, these results highlight the importance of validating tumor models for alloreactivity prior to use in preclinical testing.
MEMBER ACCOUNT
登录成功会直接打开下一页。
