PO.IM01.04 · 免疫学
肿瘤来源的细胞外囊泡作为放疗诱导免疫原性细胞死亡的关键信使,使小细胞肺癌对免疫治疗敏感
Tumor-derived extracellular vesicles as key messengers of radiotherapy-induced immunogenic cell death to sensitize small cell lung cancer to immunotherapy
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摘要 Abstract
中文摘要
背景:我们此前表明,低剂量放疗(LDRT)在SCLC的临床前模型和临床环境中均发挥免疫刺激效应,但其免疫原性细胞死亡(ICD)机制仍不清楚。由于细胞外囊泡(EVs)介导细胞间应激信号传导,我们假设肿瘤来源的EVs在放疗反应初始阶段协调免疫原性信号传导中发挥关键作用。本研究通过EV监测追踪从肿瘤到DCs的ICD信号,并阐明其在这一过程中的功能谱。
方法:对接受LDRT联合化学免疫治疗的前瞻性广泛期SCLC队列的血浆EVs以及照射后PDX/PDO来源的EVs进行蛋白质组学分析。使用照射后的细胞组分——细胞沉淀、碎片和EVs——分别激活DC-T轴。EV抑制和活细胞成像证实放射诱导的EVs(RT-EVs)激活该轴,而非照射EVs(NT-EVs)则不然。建立了SCLC CDX和PDX模型,并采集相应的同源PBMCs用于体内EV功能评估。基于稳定同位素标记的ICD追踪系统追踪了EV介导的从照射SCLC和MC-38ova细胞到DCs的免疫原性转移。
结果:蛋白质组学分析鉴定出LDRT-EVs特异性富集于DC活化通路,并表现出更强的ICD标志,被称为“Spark-EVs”。Spark-EVs比其他细胞组分更显著地增强DC和T细胞活化,其效力可与全细胞裂解物相媲美。与NT-EVs相比,Spark-EVs强效激活DC-T细胞轴,而EV释放抑制剂将这一效应逆转至对照水平。活细胞成像证实DC对Spark-EVs的摄取比NT-EVs高近三倍(p < 0.0001)。在CDX模型中,Spark-EV脉冲的DCs + anti-PD-1比NT-EVs + anti-PD-1或单用anti-PD-1更增强肿瘤抑制。用Spark-EV脉冲的hDCs致敏的患者T细胞在体外表现出增强的干性和细胞毒性。将这些T细胞过继转移到PDX模型中产生了更优的肿瘤控制。EV标记追踪显示Spark-EVs富集了增多的OVA抗原、DAMPs(如HSPD1),随后将其递送至DCs中。此外,整合的多层次蛋白质组学和预后分析鉴定出连接斑珠蛋白(JUP)作为ICD信号的潜在关键传递因子。
结论:利用基于EV的追踪,我们可视化了LDRT如何触发肿瘤细胞产生Spark-EVs,并将增强的免疫原性信号递送至DCs。此外,我们阐明了放射响应性的EV携带蛋白(如JUP、HSPD1)介导LDRT诱导的免疫原性信号的释放、传递和效应功能。这些发现确立了Spark-EVs作为LDRT驱动的ICD的关键、可靶向的信使。
查看英文原文 English abstract
Background: We previously showed low-dose radiotherapy (LDRT) exerts immunostimulatory effects in both preclinical models and clinical settings for SCLC, yet its immunogenic cell death (ICD) mechanisms remain unclear. As extracellular vesicles (EVs) mediate intercellular stress signaling, we hypothesized that tumor-derived EVs play a critical role in orchestrating immunogenic signaling in the initial stages of radiotherapy response. This study tracks ICD signals from tumor to DCs via EV monitoring and elucidate their function spectrum throughout this process.
Methods : Plasma EVs from prospective extensive-stage-SCLC cohorts treated with LDRT plus chemo-immunotherapy and PDX/PDO-derived EVs post-irradiation underwent proteomic profiling. Post-irradiation cellular components - cell pellets, debris, and EVs - were used to activate DC-T axis respectively. EV inhibition and live-cell imaging confirmed radiation-induced EVs (RT-EVs) activate the axis versus non-irradiated EVs (NT-EVs). SCLC CDX and PDX models were established, and corresponding homogeneous PBMCs were collected for in vivo EV function evaluation.An ICD tracking system based on stable isotope labeling traced EV-mediated immunogenic transfer from irradiated SCLC and MC-38ova cells to DCs.
Results : Proteomic analysis identified LDRT-EVs were specifically enriched in DC activation pathways and exhibited stronger ICD hallmarks, termed “Spark-EVs”. Spark-EVs significantly enhanced DC and T cell activation more than other cellular components, with efficacy comparable to whole-cell lysates. Spark-EVs potently activated the DC-T cell axis compared to NT-EVs, whereas the EV release inhibitor reversed this effect to control levels. Live-cell imaging confirmed nearly threefold greater DC uptake of Spark-EVs than NT-EVs (p < 0.0001). In CDX models, Spark-EV-pulsed DCs + anti-PD-1 enhanced tumor suppression versus NT-EVs + anti-PD-1 or anti-PD-1 alone. Patient T cells primed with Spark-EV-pulsed hDCs showed enhanced stemness and cytotoxicity in vitro. Adoptive transfer of these T cells into PDX models yielded superior tumor control. EV-labeled tracing showed that Spark-EVs were enriched with increased OVA antigens, DAMPs (e.g. HSPD1), which deliver into DCs then. Additionally, Integrated multi-level proteomics and prognostic analysis identified Junction plakoglobin (JUP) as a potential key transmitter of ICD signal.
Conclusion : Using EV-based tracing, we visualized how LDRT triggers tumor cells to generate Spark-EVs, which deliver enhanced immunogenic signals to DCs. Furthermore, we delineate that radiation-responsive EV-borne proteins (e.g. JUP, HSPD1) that mediate the release, transmission, and effector functions of LDRT-induced immunogenic signaling. These findings establish Spark-EVs as key, targetable messengers of LDRT-driven ICD.
利益披露 Disclosure
S. Liu, None..
K. Kang, None..
Z. Yao, None..
R. Luo, None..
H. Wang, None..
Z. Peng, None..
S. Liao, None..
Y. Zeng, None..
R. Tong, None..
J. Zeng, None..
W. Xiao, None..
J. Xue, None..
L. Yi, None..
C. Wang, None..
Y. Lu, None.