PO.IM01.10 · 免疫学
硼替佐米通过固有免疫激活增强PD-1阻断在肺鳞状细胞癌中的抗肿瘤疗效
Bortezomib enhances anti-tumor efficacy of PD-1 blockade in lung squamous cell carcinoma via innate immune activation
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：与传统化疗相比，免疫检查点抑制剂改善了肺鳞状细胞癌患者的生存结局。然而，诸如应答率低和获得性耐药等挑战依然存在。尽管蛋白酶体抑制剂因其独特的作用机制而显示出抗肿瘤潜力，但其协同增强免疫治疗的能力尚未得到充分证实。本研究旨在探究硼替佐米与PD-1阻断在肺鳞状细胞癌中的一种新型联合策略。
方法：我们建立了共培养系统，通过流式细胞术评估淋巴细胞的细胞毒性和细胞因子产生。使用肺鳞状细胞癌的同基因和人源化小鼠模型评估肿瘤生长和免疫浸润对硼替佐米（单用或与抗PD-1联合）的响应。通过免疫组化分析肿瘤组织中的免疫浸润。通过Western印迹和聚合酶链反应检测信号通路激活和趋化因子表达。使用基因敲低或药理抑制扰动固有免疫通路的关键分子，以阐明其潜在机制。
结果：用硼替佐米预处理肺鳞状细胞癌细胞增强了淋巴细胞介导的杀伤，并在共培养中增加了IFN-gamma和颗粒酶B的分泌。在同基因模型中，硼替佐米促进了瘤内淋巴细胞浸润并与PD-1阻断产生协同作用，导致CD8⁺ T细胞和颗粒酶B⁺细胞积累增加。这些发现在人源化小鼠模型中得到了证实。机制上，硼替佐米触发了趋化因子表达（例如CCL5）并激活了固有免疫通路的组分，包括TBK、IRF3、IKK和NF-κB。这种效应未被STING或RIG-I敲低所消除。相比之下，对MYD88的药理抑制抑制了TBK和IKK磷酸化，并逆转了硼替佐米诱导的CCL5上调。
结论：硼替佐米通过激活TLR/MYD88依赖性固有免疫通路、增强趋化因子介导的免疫浸润，增强了PD-1阻断在肺鳞状细胞癌中的疗效。这些结果支持进一步开发该组合作为一种有前景的治疗策略。
查看英文原文 English abstract
Background: Immune checkpoint inhibitors have improved survival outcomes for patients with lung squamous cell carcinoma compared to conventional chemotherapy. However, challenges such as low response rates and acquired resistance remain. Although proteasome inhibitors have shown antitumor potential owing to their unique mechanism of action, their ability to synergistically enhance immunotherapy is not well established. This study aimed to investigate a novel combinatory strategy of bortezomib and PD-1 blockade in lung squamous cell carcinoma.
Methods: We established co-culture systems to assess lymphocyte cytotoxicity and cytokine production by flow cytometry. Syngeneic and humanized mouse models of lung squamous cell carcinoma were used to evaluate tumor growth and immune infiltration in response to bortezomib, alone or in combination with anti-PD-1. Immune infiltration in tumor tissues was analyzed by immunohistochemistry. Signaling pathway activation and chemokine expression were examined by Western blot and polymerase chain reaction. Key molecules of innate immune pathways were perturbed using genetic knockdown or pharmacological inhibition to delineate the underlying mechanism.
Results: Pre-treatment of lung squamous cell carcinoma cells with bortezomib enhanced lymphocyte-mediated killing and increased secretion of IFN-gamma and granzyme B in co-culture. In syngeneic models, bortezomib promoted intratumoral lymphocyte infiltration and synergized with PD-1 blockade, leading to increased CD8⁺ T cell and granzyme B⁺ cell accumulation. These findings were corroborated in humanized mouse models. Mechanistically, bortezomib triggered chemokine expression (e.g., CCL5) and activated components of the innate immune pathway, including TBK, IRF3, IKK, and NF-κB. This effect was not abrogated by STING or RIG-I knockdown. In contrast, pharmacologic inhibition of MYD88 suppressed TBK and IKK phosphorylation and reversed CCL5 upregulation induced by bortezomib.
Conclusion: Bortezomib augments the efficacy of PD-1 blockade in lung squamous cell carcinoma by activating a TLR/MYD88-dependent innate immune pathway, enhancing chemokine-mediated immune infiltration. These results support the further development of this combination as a promising therapeutic strategy.
利益披露 Disclosure
X. Jin, None..
J. Zhong, None..
S. Peng, None..
S. Xu, None.