PO.IM01.12 · 免疫学
高剂量维生素C诱导ROS依赖性钙网蛋白暴露以驱动免疫原性细胞死亡和癌症免疫监视
High-dose vitamin C induces ROS-dependent calreticulin exposure to drive immunogenic cell death and cancer immune surveillance
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：高剂量维生素C（VitC）在免疫功能正常的小鼠中相较免疫缺陷小鼠显示出更优的抗癌活性，提示存在免疫依赖性的作用机制。由于高剂量VitC产生大量活性氧（ROS），我们推测ROS可能诱导免疫原性细胞死亡（ICD）——一种以释放损伤相关分子模式（DAMPs）为特征的调节性细胞死亡形式，能够增强抗原提呈并促进抗肿瘤免疫。
方法：对接受高剂量VitC治疗的小鼠乳腺和结肠肿瘤进行空间转录组学和免疫荧光分析，以量化氧化应激、DAMP动员和免疫细胞浸润。为剖析ROS和ICD的功能作用，给小鼠施用高剂量VitC，并联合抗氧化剂N-乙酰半胱氨酸或一种阻断钙网蛋白（一种对ICD诱导至关重要的早期DAMP）的抗体。
结果：VitC治疗在免疫功能正常和免疫功能低下小鼠的肿瘤中均引起显著的氧化应激；然而，肿瘤生长抑制仅发生在免疫功能正常的动物中。高剂量VitC分别触发了ROS依赖性的DAMPs钙网蛋白暴露和HMGB1释放。这伴随着肿瘤微环境的显著重塑，包括细胞毒性CD8⁺T细胞和自然杀伤细胞浸润的增加，以及免疫抑制性调节性T细胞的减少。阻断钙网蛋白有效地破坏了ICD级联反应，阻止了免疫微环境重塑，并完全消除了VitC的抗肿瘤疗效。
结论：高剂量VitC通过ROS依赖性的钙网蛋白和HMGB1动员促进ICD，且钙网蛋白是其免疫介导的抗肿瘤活性所必需的。这些结果为正在进行的ALFEO临床试验（ECTR2022-502101-15-00）内的转化分析提供了机制依据，该试验正在评估高剂量VitC联合纳武利尤单抗（nivolumab）和伊匹木单抗（ipilimumab）用于错配修复正常的结直肠癌。由意大利卫生部Next Generation EU - PNRR M6C2 - PNRR-MAD-2022-12376593资助。
查看英文原文 English abstract
Background: High-dose vitamin C (VitC) has shown superior anticancer activity in immunocompetent compared with immunodeficient mice, suggesting an immune-dependent mechanism of action. Because high-dose VitC generates substantial reactive oxygen species (ROS), we hypothesized that ROS might induce immunogenic cell death (ICD)-a regulated form of cell death characterized by the release of damage-associated molecular patterns (DAMPs) that enhance antigen presentation and promote antitumor immunity.
Methods: Spatial transcriptomic and immunofluorescence analyses were performed on breast and colon tumors from mice treated with high-dose VitC to quantify oxidative stress, DAMP mobilization, and immune cell infiltration. To dissect the functional role of ROS and ICD, mice were treated with high-dose VitC in combination with the antioxidant N-acetylcysteine or an antibody blocking calreticulin (an early DAMP essential for ICD induction).
Results: VitC treatment caused marked oxidative stress in tumors from both immunocompetent and immunocompromised mice; however, tumor growth inhibition occurred exclusively in immunocompetent animals. High-dose VitC triggered ROS-dependent exposure and release of the DAMPs calreticulin and HMGB1, respectively. This was accompanied by substantial remodeling of the tumor microenvironment, including increased infiltration of cytotoxic CD8⁺ T cells and natural killer cells, and a reduction in immunosuppressive regulatory T cells. Blocking calreticulin effectively disrupted the ICD cascade, prevented immune microenvironment remodeling, and completely abrogated the antitumor efficacy of VitC.
Conclusions: High-dose VitC promotes ICD through ROS-dependent mobilization of calreticulin and HMGB1, and calreticulin is required for its immune-mediated antitumor activity. These results provide a mechanistic rationale for ongoing translational analyses within the ALFEO clinical trial (ECTR2022-502101-15-00), which is evaluating high-dose VitC in combination with nivolumab and ipilimumab in mismatch-repair-proficient colorectal cancer. Funded by the Italian Ministry of Health Next Generation EU - PNRR M6C2 - PNRR-MAD-2022-12376593.
利益披露 Disclosure
A. Cavaliere, None..
F. Maione, None..
M. Macagno, None..
V. Amodio, None..
R. Chilà, None..
M. Turi, None..
M. Escobosa, None..
G. Germano, None..
S. Lamba, None..
C. Baretta, None..
A. Brignacca, None..
V. Pessei, None..
E. Perez, None..
D. Grases, None..
A. Bartolini, None..
F. Penna, None..
E. Porta, None..
R. Rad, None..
A. Gullà, None.
A. Bardelli,
Neophore Stock.
T. Troiani, None..
S. Siena, None..
A. Sartore-Bianchi, None.
F. Di Nicolantonio,
Illumina Other, Speaker's fees.