PO.IM02.05 · 免疫学
SPIN1 通过诱导 M2 巨噬细胞极化并抑制 CD8+ T 细胞免疫驱动胃癌 PD-1 免疫治疗耐药
SPIN1 drives PD-1 immunotherapy resistance in gastric cancer by inducing M2 macrophage polarization and suppressing CD8⁺ T-cell immunity
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
引言：对抗 PD-1 治疗的耐药仍是改善胃癌（GC）结局的主要障碍。尽管染色质阅读器 SPIN1 已被认为与肿瘤进展相关，但其在塑造肿瘤免疫微环境（TIME）及驱动免疫治疗耐药中的作用尚不明确。本研究旨在阐明 SPIN1 如何调节 TIME 内的免疫成分以促进对 PD-1 阻断的耐药。
实验方法：通过多重免疫组化（mIHC）评估接受抗 PD-1 治疗的 GC 患者中 SPIN1 表达及免疫浸润模式——包括 CD8+ T 细胞、CD163+ 和 CD206+ 巨噬细胞及 TIM-3+ 耗竭淋巴细胞。使用稳定敲低或过表达 SPIN1 的 GC 细胞系，通过巨噬细胞共培养实验、代谢分析及 M1/M2 标志物的流式细胞术表征进行机制研究。在接受 SPIN1 小分子抑制剂、抗 PD-1 抗体或两者联合治疗的同基因小鼠模型中评估抗肿瘤疗效。
数据摘要：临床上，SPIN1 表达在 PD-1 阻断的无应答者中显著高于应答者。SPIN1 水平升高与免疫抑制性 M2 巨噬细胞（CD163+/CD206+）浸润增加及肿瘤组织中 CD8+ T 细胞减少密切相关。体外实验中，沉默 SPIN1 减弱、而过表达 SPIN1 增强 M2 相关基因表达及表面标志物。流式细胞术证实 SPIN1 驱动巨噬细胞向 M2 表型极化。SPIN1 条件化的巨噬细胞随后抑制 CD8+ T 细胞增殖和细胞毒功能，同时诱导 T 细胞耗竭，表现为 PD-1、TIM-3 和 LAG-3 表达增加。体内实验中，药理学抑制 SPIN1 通过减少 M2 巨噬细胞聚集并恢复 CD8+ T 细胞浸润和效应活性，重塑了 TIME。值得注意的是，将 SPIN1 抑制剂与抗 PD-1 治疗联合，与任一单药相比，产生协同抗肿瘤反应并显著逆转获得性耐药。
结论：本研究确定 SPIN1 是 GC 中免疫抑制和治疗耐药的关键调控因子。通过促进 M2 巨噬细胞极化并驱动 CD8+ T 细胞耗竭，SPIN1 建立了限制 PD-1 阻断疗效的 TIME。这些发现凸显 SPIN1 既是免疫治疗反应的预测性生物标志物，也是使胃肿瘤对基于 PD-1 的免疫治疗敏感化的有前景治疗靶点。
查看英文原文 English abstract
Introduction: Resistance to anti-PD-1 therapy remains a major obstacle to improving outcomes in gastric cancer (GC). Although the chromatin reader SPIN1 has been implicated in tumor progression, its contribution to shaping the tumor immune microenvironment (TIME) and driving immunotherapy resistance is not well understood. This study aimed to elucidate how SPIN1 modulates immune components within the TIME to promote resistance to PD-1 blockade.
Experimental Procedures: SPIN1 expression and immune infiltration patterns-including CD8⁺ T cells, CD163⁺ and CD206⁺ macrophages, and TIM-3⁺ exhausted lymphocytes-were assessed by multiplex immunohistochemistry (mIHC) in GC patients treated with anti-PD-1 therapy. Mechanistic studies were performed using GC cell lines with stable SPIN1 knockdown or overexpression in macrophage co-culture assays, metabolic profiling, and flow cytometric characterization of M1/M2 markers. Antitumor efficacy was evaluated in syngeneic mouse models treated with a SPIN1 small-molecule inhibitor, anti-PD-1 antibody, or the combination.
Data Summary: Clinically, SPIN1 expression was significantly higher in non-responders than in responders to PD-1 blockade. Elevated SPIN1 levels strongly correlated with increased infiltration of immunosuppressive M2 macrophages (CD163⁺/CD206⁺) and reduced CD8⁺ T-cell presence in tumor tissue. In vitro, SPIN1 silencing diminished, whereas SPIN1 overexpression enhanced, M2-associated gene expression and surface markers. Flow cytometry confirmed that SPIN1 drives macrophage polarization toward an M2 phenotype. SPIN1-conditioned macrophages subsequently suppressed CD8⁺ T-cell proliferation and cytotoxic function while inducing T-cell exhaustion, evidenced by increased PD-1, TIM-3, and LAG-3 expression. In vivo, pharmacologic inhibition of SPIN1 reshaped the TIME by reducing M2 macrophage accumulation and restoring CD8⁺ T-cell infiltration and effector activity. Notably, combining a SPIN1 inhibitor with anti-PD-1 therapy produced a synergistic antitumor response and significantly reversed acquired resistance compared with either single agent.
Conclusions: This study identifies SPIN1 as a key regulator of immune suppression and therapeutic resistance in GC. By promoting M2 macrophage polarization and driving CD8⁺ T-cell exhaustion, SPIN1 establishes a TIME that limits the efficacy of PD-1 blockade. These findings highlight SPIN1 as both a predictive biomarker for immunotherapy response and a promising therapeutic target for sensitizing gastric tumors to PD-1-based immunotherapy.
利益披露 Disclosure
B. Lyu, None..
X. lin, None.