PO.IM01.01 · 免疫学
恢复TUSC2功能可增强NK细胞细胞毒性以及体内和体外的抗肿瘤免疫
Restoring TUSC2 function boosts NK cell cytotoxicity and antitumor immunity in vivo and in vitro
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：肿瘤抑制候选基因2（TUSC2）位于染色体3p21.3，在包括非小细胞肺癌（NSCLC）、小细胞肺癌（SCLC）、间皮瘤、乳腺癌和头颈部癌在内的多种人类癌症中频繁缺失。TUSC2的缺失与生存期缩短和肿瘤侵袭性增加相关。尽管已知TUSC2能抑制肿瘤细胞增殖并诱导凋亡，但其在免疫系统中——尤其是在天然淋巴细胞群体中——的调控作用仍未得到充分界定。基于我们此前将TUSC2鉴定为一种参与钙调节和免疫调控的线粒体蛋白的工作，我们假设TUSC2部分通过增强NK细胞细胞毒性来发挥抗肿瘤作用。
方法：以同基因肿瘤细胞（344SQ）攻击Tusc2敲除（Tusc2 KO）和野生型（Tusc2 WT）小鼠，并使用表达TUSC2的脂质颗粒（quaratusugene ozeplasmid，Quar Oze）进行治疗。治疗组在肿瘤建立后从细胞系注射后第8天开始接受Quar Oze，而预防组在肿瘤建立前、从细胞系注射前2天开始接受Quar Oze。对照组接受空脂质颗粒。细胞系注射三周后，评估肿瘤体积，并对小鼠实施安乐死以收集肿瘤、脾脏和肿瘤引流淋巴结（TDLN）。使用流式细胞术分析免疫细胞表型和细胞毒性标志物。体外研究通过测量CD107a脱颗粒和基于CellTrace Violet的增殖，评估Quar Oze处理后NK细胞的细胞毒性功能。
结果：在治疗组中，67%的Tusc2 KO小鼠和33%的Tusc2 WT小鼠实现了完全肿瘤消退，其余所有小鼠与对照组相比均显示出显著的肿瘤缩小。预防性给药未诱导完全的肿瘤清除，但在所有小鼠中均一致地减少了肿瘤生长。肿瘤微环境的免疫谱分析显示，Quar Oze强有力地增强了NK细胞细胞毒性，特别是增加了granzyme B和穿孔素（perforin）的表达。体外实验证实，TUSC2的恢复显著增加了NK细胞脱颗粒和增殖，支持了体内的发现。
结论：TUSC2通过增强NK细胞的细胞毒性功能，充当天然抗肿瘤免疫的关键增强剂。通过Quar Oze递送TUSC2可抑制肿瘤进展，并在许多情况下驱动肿瘤的完全消除。这些结果凸显了TUSC2作为一种强效免疫调节性肿瘤抑制因子的地位，并支持将其开发为一种既直接靶向肿瘤细胞又激活NK细胞介导免疫的双功能疗法。
查看英文原文 English abstract
Background: Tumor Suppressor Candidate 2 (TUSC2), located on chromosome 3p21.3, is frequently deleted in multiple human cancers, including non-small cell lung carcinoma (NSCLC), small cell lung carcinoma (SCLC), mesothelioma, breast cancer, and head-and-neck cancers. Loss of TUSC2 is associated with reduced survival and increased tumor aggressiveness. Although TUSC2 is known to suppress tumor cell proliferation and induce apoptosis, its regulatory role in the immune system-particularly in innate lymphoid populations-remains insufficiently defined. Building on our prior work identifying TUSC2 as a mitochondrial protein involved in calcium regulation and immune modulation, we hypothesized that TUSC2 exerts antitumor effects in part by enhancing NK cell cytotoxicity.
Methods Tusc2 knockout (Tusc2 KO) and wild-type (Tusc2 WT) mice were challenged with syngeneic tumor cells (344SQ) and treated with TUSC2-expressing lipoparticles (quaratusugene ozeplasmid, Quar Oze). The therapeutic group received Quar Oze after tumor establishment starting at day 8 from cell line injection, while prophylaxis group received Quar Oze before tumor establishment, starting 2 days before injection of cell lines. Control groups received empty lipoparticles. After three weeks from cell line injection, tumor volumes were assessed, and mice were euthanized for collection of tumors, spleens, and tumor-draining lymph nodes (TDLN). Immune cell phenotypes and cytotoxic markers were analyzed using flow cytometry. In vitro studies evaluated NK cell cytotoxic function following Quar Oze treatment by measuring CD107a degranulation and CellTrace Violet-based proliferation
Results In the therapeutic treatment group, 67% of Tusc2 KO mice and 33% of Tusc2 WT mice achieved complete tumor regression, with all remaining mice showing significant tumor reduction compared with controls. Prophylactic administration did not induce complete tumor clearance but consistently reduced tumor growth across all mice. Immune profiling of the tumor microenvironment revealed that Quar Oze robustly enhanced NK cell cytotoxicity, particularly increasing granzyme B and perforin expression. In vitro assays confirmed that TUSC2 restoration significantly increased NK cell degranulation and proliferation, supporting the in vivo findings.
Conclusion TUSC2 acts as a critical enhancer of innate antitumor immunity by boosting NK cell cytotoxic function. Therapeutic delivery of TUSC2 via Quar Oze suppresses tumor progression and, in many cases, drives complete tumor elimination. These results highlight TUSC2 as a potent immunomodulatory tumor suppressor and support its development as a dual-function therapeutic that directly targets tumor cells while also activating NK cell-mediated immunity
利益披露 Disclosure
M. A. Mohammed, None..
J. Tonello, None..
M. S. Berger, None.