简单的膳食补充剂可以增强抗癌免疫细胞

诸平

Researchers at Penn Medicine discovered that a ketogenic diet or BHB supplements may boost CAR T cell therapy’s effectiveness in fighting cancer by enhancing T cell metabolism. While promising early results have led to a Phase I clinical trial, further evidence is needed before dietary recommendations can be made.

据美国宾夕法尼亚大学医学院（University of Pennsylvania School of Medicine）2024年12月29日提供的消息，简单的膳食补充剂可以增强抗癌免疫细胞（Simple Dietary Supplement Could Supercharge Cancer-Fighting Immune Cells）。

实验室研究揭示了一种简单而有前途的方法来增强个性化细胞治疗（Laboratory studies uncover a simple yet promising approach to enhance personalized cell therapy）

根据宾夕法尼亚大学佩雷尔曼医学院和艾布拉姆森癌症中心（Perelman School of Medicine and the Abramson Cancer Center at the University of Pennsylvania）的研究人员进行的一项研究，一种膳食补充剂可能提供一种提高CAR - T细胞治疗效果的新方法。尽管这种方法需要通过临床试验进行验证，但最近在第66届美国血液学会（ASH）年会上和博览会{66th American Society of Hematology (ASH) Annual Meeting and Exposition}的新闻发布会上公布的早期发现表明，这是一种潜在的可负担和可获得的策略，可以提高CAR - T细胞的功能和抗癌能力。

CAR - T细胞疗法（CAR T cell therapy）是宾夕法尼亚大学医学院最先开发的一种个性化癌症治疗方法，它通过重新编程患者的免疫细胞来靶向并摧毁癌细胞。

“成千上万的血癌患者已经成功地用CAR - T细胞疗法治疗，但它仍然不是对每个人都有效，”联合首席作者、博士后刘姗（Shan Liu,音译）博士在ASH年会上交流了这项研究成果。“我们采用了一种创新的方法来改善CAR - T细胞疗法，通过饮食靶向T细胞，而不是进一步的基因工程。”原报告详见：Shan Liu, Puneeth Guruprasad, Kecheng Han, Luca Paruzzo, Alexander Shestov, Andre Kelly, Kevin R. Amses, Amichay Afriat, Bhoomi Madhu, Lev Litichevskiy, Ezra Dubowitz, Neil Tangal, Alana McSween, Melody Tan, Alberto Carturan, Andrew Lee, Yunlin Zhang, Giulia Gabrielli, Raymone Pajarillo, Ruchi P. Patel, Guido Ghilardi, Patrizia Porazzi, Stephen J. Schuster, Roddy S. O'Connor, Michael C. Milone, Joshua Rabinowitz, Maayan Levy, Marco Ruella. Ketogenic Diet Enhances CAR T Cell Antitumor Function Via β-Hydroxybutyrate (Abstract 4). 66th American Society of Hematology (ASH) Annual Meeting and Exposition, Sunday, December 8, 2024. https://ash.confex.com/ash/2024/webprogram/Paper208913.html

参与此项研究的除了来自美国宾夕法尼亚大学的研究人员之外，还有来自美国普林斯顿大学（Princeton University, Princeton, NJ, USA）的研究人员。

刘姗和普尼斯·古鲁普拉萨德（Puneeth Guruprasad）博士共同领导了这项研究，普尼斯·古鲁普拉萨德博士在宾夕法尼亚大学获得博士学位，现在是佩雷尔曼医学院（Perelman School of Medicine）的一名医科学生。该研究的主要作者在共同通讯作者马可·鲁娜（Marco Ruella）的指导下工作，马可·鲁娜医学博士是血液肿瘤学（Hematology-Oncology,）助理教授，细胞免疫治疗中心（Center for Cellular Immunotherapies）的研究员，宾夕法尼亚大学医学院淋巴瘤项目（Penn Medicine’s Lymphoma Program）的科学主任；以及微生物学助理教授玛雅·利维（Maayan Levy）博士。

CAR - T细胞更倾向于将BHB作为燃料来源（CAR T cells prefer BHB as a fuel source）

首先，研究小组用弥漫性大B细胞淋巴瘤(diffuse-large B-cell lymphoma)小鼠模型测试了几种不同饮食——包括生酮饮食(ketogenic diet)、高纤维饮食（high-fiber diet）、高脂肪饮食（high-fat diet）、高蛋白饮食（high-protein diet）、高胆固醇饮食（high cholesterol diet）以及对照饮食（control diet））对CAR - T细胞抗肿瘤能力的影响。他们发现，与所有其他饮食相比，接受生酮饮食的小鼠的肿瘤控制和存活率有所改善。在随后的研究中，他们发现更高水平的β-羟基丁酸酯（beta-hydroxybutyrate简称BHB），一种由肝脏对生酮饮食产生的代谢物，是这种效果的关键媒介。

这项研究建立在玛雅·利维团队之前的工作（previous work from Levy’s team）基础上，他们在实验室实验中发现BHB强烈抑制结直肠肿瘤的生长。

普尼斯·古鲁普拉萨德说：“我们的理论是，CAR - T细胞更喜欢BHB作为燃料来源，而不是我们体内的标准糖，如葡萄糖（glucose）。所以，增加体内BHB的水平会让CAR - T细胞有更多的能力来消灭癌细胞。”

患者样本和健康志愿者的转化研究（Translational studies in patient samples and healthy volunteers）

接下来，研究小组在人类癌症的实验室模型（标准饮食）中测试了BHB补充剂与CAR - T细胞疗法的结合；结果显示，绝大多数小鼠的癌症完全消失，并导致更高的CAR - T细胞扩增和激活。BHB在人体中以不同的水平自然存在，为了了解BHB是否对人类有类似的影响，研究小组评估了最近接受CAR - T细胞治疗的患者的血液样本，发现更高的BHB水平与患者体内更好的CAR - T细胞扩增有关。他们还观察了服用BHB补充剂的健康志愿者的T细胞，发现正常T细胞在接触BHB后产生能量的方式发生了类似的变化。

过去对几种癌症类型的研究着眼于饮食干预的影响，如高纤维饮食，对癌症免疫治疗的反应，然而，在这项研究中，BHB效应背后的机制似乎源于血液中的代谢变化，而不是通过肠道微生物群，就像高纤维饮食一样。

下一步和潜在影响(Next steps and potential impact)

补充BHB可以改善对CAR - T细胞疗法的反应的理论正在宾夕法尼亚大学医学院的艾布拉姆森癌症中心进行一期临床试验(Phase I clinical trial at Penn Medicine’s Abramson Cancer Center)。

玛雅·利维说：“我们讨论的是一种相对便宜且毒性低的干预方法。如果临床试验数据得到证实，我很兴奋地想到，如何将这样一个相当简单的方法与饮食干预或其他更传统的方法结合起来，以增强抗癌效果。”

该临床试验由首席研究员、医学博士、血液肿瘤学助理教授Elise Chong领导，将很快开始招募复发或难治性大B细胞淋巴瘤患者，这些患者正在接受市售的抗CD19 CAR - T细胞疗法(anti-CD19 CAR T cell therapy)作为治疗的一部分。

马可·鲁娜说：“作为一名医生和科学家，我和我的病人一样，对更好地治疗癌症的潜在新策略感到兴奋，我很高兴看到这项研究从实验室台面转移到转化研究，现在又进入临床试验。然而，我们要强调的是，在这一点上，研究仍然是初步的，在我们有明确的临床证据之前，我们不会根据这项研究向患者提出任何饮食或补充剂建议。”

该研究部分由宾夕法尼亚大学CHOP微生物组核心(Penn-CHOP Microbiome Core)项目资助。

上述介绍，仅供参考。欲了解更多信息，敬请注意浏览原文或者相关报道。

Douglas B. Cines Honored for Contributions to Hematology

Keto diet metabolite may power up CAR T cells to kill cancer

Abstract

Introduction. Several mechanisms of resistance have been identified for chimeric antigen receptor (CAR) T cell therapy; however, there are limited data on the impact of lifestyle factors, such as diet, on CAR T cell efficacy. Indeed, diet-derived metabolites can modulate T cell functions through the regulation of metabolic, epigenetic, and transcriptional processes. Here, we investigated whether diet can affect responses to CAR T cell treatment.

Methods and Results. To this end, we implanted diffuse large B-cell lymphoma (DLBCL) tumors (A20) into immunocompetent mice (Balb/c), and fed them one of five representative diets, including ketogenic, high-fiber, high-fat, high-protein, Western (i.e., high cholesterol), and a macro- and micronutrient content-matched control diet. Upon tumor engraftment, we infused murine anti-CD19 CAR T cells (CART19). Mice fed a ketogenic diet showed improved tumor control and overall survival relative to all other screened diets. As expected, the level of β-hydroxybutyrate (BHB), the principal metabolite produced during ketosis, was significantly higher in ketogenic diet-fed mice compared to other groups. Since effector T cells can utilize BHB to fuel the citric acid cycle, we hypothesized that BHB can serve as a more efficient energy source than glucose for active CAR T cells, leading to more pronounced effector responses.

Therefore, we tested the effect of BHB alone on several xenograft cancer models in immunodeficient NOD-SCID gamma chain-deficient (NSG) mice. First, DLBCL tumors were implanted into NSG mice (5×10⁶ CD19⁺ OCI-Ly18 cells, subcutaneous), and BHB was oral gavaged daily. On day 11 post-implantation, a suboptimal dose of CART19 (3×10⁶ CAR⁺ cells) was infused. Mice receiving both oral BHB and CART19 demonstrated potent tumor control (complete response, CR 6/7) compared to mice receiving a vehicle gavage (CR 1/7). BHB+CART19-treated mice also showed higher peripheral CAR T cell expansion and elevated serum effector cytokines. Furthermore, BHB given ad libitum in the drinking water led to improved tumor control of anti-mesothelin CAR-T in AsPC-1 (pancreatic cancer, subcutaneous) and anti-CD19 CAR-T in Nalm6 (B cell acute lymphoblastic leukemia, intravenous) xenografts.

Mechanistically, using carbon-13 (¹³C) isotope labeling, we found that antigen-activated CAR T cells preferentially integrate carbon from BHB into the citric acid cycle components over that of standard glucose. This process fuels CAR-T oxidative phosphorylation and increases their oxygen consumption, as confirmed by the Seahorse Assay (Agilent Seahorse XF). To determine whether BHB modulates epigenetic accessibility in CAR T cells, we performed an assay for transposase-accessible chromatin with sequencing (ATAC-seq) on CAR T cells treated with or without BHB. We found that BHB-treatment exposed crucial effector and memory genes (e.g., FOXO1, TCF7, GZMB) in CAR T cells. This likely reflects increased Acetyl-CoA from BHB entering the CAR-T nucleus and acetylating histones. Finally, we found that deleting BDH1, the key enzyme involved in BHB metabolism to Acetyl-CoA, in CAR-T reduces the functional benefit of BHB. This further confirms that BHB enhances CAR-T functions through metabolic modulation.

To test the translational relevance of these findings, we retrospectively analyzed CART19 patient serum (n=17, all LBCL) taken 7 days post-infusion from the NCT02030834 trial using mass spectrometry. In line with our preclinical results that BHB can support CAR-T proliferation, BHB serum concentration positively correlated with CART19 expansion (P = 0.0164). Lastly, we produced CAR T cells from the leukapheresis products of two CART19 patients. We found that providing BHB in the cell culture media during ex vivo manufacturing boosted patient T cell proliferation, resulting in a ~4× increase in absolute cell count.

Conclusions. Our results demonstrate that ketogenic diet-derived BHB can be provided as a dietary intervention to augment CAR-T function in multiple cancer models. The key mechanism involves the enhancement of the citric acid cycle and histone modifications during CAR T cell activation. The results of this study will be translated into a first-in-human clinical trial of BHB-supplementation during CART19 treatment for relapsed or refractory B cell lymphoma.