Our previous work showed that the anti-TGF-β/PD-L1 bispecific antibody YM101 effectively overcame anti-PD-L1 resistance in immune-excluded tumor models. However, in immune-desert models, the efficacy of YM101 was limited. Bivalent manganese (Mn2+) is identified as a natural stimulator of interferon genes (STING) agonist, which might enhance cancer antigen presentation and improve the therapeutic effect of YM101. The effect of Mn2+ on STING pathway was validated by western blotting and enzyme-linked immunosorbent assay. Dendritic cell (DC) maturation was measured by flow cytometry. The synergistic effect between Mn2+ and YM101 in vitro was determined by one-way mixed lymphocyte reaction, CFSE dilution assay, and cytokine detection. The in vivo antitumor effect of Mn2+ plus YM101 therapy was assessed in CT26, EMT-6, H22, and B16 tumor models. Flow cytometry, RNA-seq, and immunofluorescent staining were adopted to investigate the alterations in the tumor microenvironment. Mn2+ could activate STING pathway and promote the maturation of human and murine DC. The results of one-way mixed lymphocyte reaction showed that Mn2+ synergized YM101 in T cell activation. Moreover, in multiple syngeneic murine tumor models, Mn2+ plus YM101 therapy exhibited a durable antitumor effect and prolonged the survival of tumor-bearing mice. Relative to YM101 monotherapy and Mn2+ plus anti-PD-L1 therapy, Mn2+ plus YM101 treatment had a more powerful antitumor effect and a broader antitumor spectrum. Mechanistically, Mn2+ plus YM101 strategy simultaneously regulated multiple components in the antitumor immunity and drove the shift from immune-excluded or immune-desert to immune-inflamed tumors. The investigation in the TME indicated Mn2+ plus YM101 strategy activated innate and adaptive immunity, enhanced cancer antigen presentation, and upregulated the density and function of tumor-infiltrating lymphocytes. This normalized TME and reinvigorated antitumor immunity contributed to the superior antitumor effect of the combination therapy. Combining Mn2+ with YM101 has a synergistic antitumor effect, effectively controlling tumor growth and prolonging the survival of tumor-bearing mice. This novel cocktail strategy has the potential to be a universal regimen for inflamed and non-inflamed tumors.

中文翻译：

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联合攻克：锰协同抗TGF-β/PD-L1双特异性抗体YM101克服非炎症性癌症的免疫治疗耐药性

我们之前的工作表明，抗 TGF-β/PD-L1 双特异性抗体 YM101 有效克服了免疫排除肿瘤模型中的抗 PD-L1 耐药性。然而，在免疫沙漠模型中，YM101 的功效是有限的。二价锰 (Mn2+) 被鉴定为干扰素基因 (STING) 激动剂的天然刺激物，可增强癌症抗原呈递并提高 YM101 的治疗效果。通过蛋白质印迹和酶联免疫吸附试验验证了 Mn2+ 对 STING 通路的影响。通过流式细胞术测量树突细胞 (DC) 的成熟。Mn2+和YM101在体外的协同作用通过单向混合淋巴细胞反应、CFSE稀释测定和细胞因子检测确定。在 CT26、EMT-6、H22 和 B16 肿瘤模型中评估了 Mn2+ 加 YM101 疗法的体内抗肿瘤作用。采用流式细胞术、RNA-seq和免疫荧光染色来研究肿瘤微环境的变化。Mn2+ 可以激活 STING 通路，促进人和鼠 DC 的成熟。单向混合淋巴细胞反应的结果显示Mn2+在T细胞活化中协同YM101。此外，在多个同源小鼠肿瘤模型中，Mn2+ 加 YM101 疗法表现出持久的抗肿瘤作用并延长了荷瘤小鼠的存活时间。相对于YM101单药治疗和Mn2++抗PD-L1治疗，Mn2++YM101治疗具有更强大的抗肿瘤作用和更广的抗肿瘤谱。从机制上讲，Mn2+ 加 YM101 策略同时调节抗肿瘤免疫中的多种成分，并推动从免疫排斥或免疫沙漠向免疫炎症肿瘤的转变。TME 中的研究表明 Mn2+ 加 YM101 策略激活先天免疫和适应性免疫，增强癌抗原呈递，并上调肿瘤浸润淋巴细胞的密度和功能。这种标准化的 TME 和重振抗肿瘤免疫力有助于联合疗法的优越抗肿瘤效果。Mn2+与YM101结合具有协同抗肿瘤作用，有效控制肿瘤生长，延长荷瘤小鼠的生存期。这种新颖的鸡尾酒策略有可能成为炎症和非炎症肿瘤的通用方案。这种标准化的 TME 和重振抗肿瘤免疫力有助于联合疗法的优越抗肿瘤效果。Mn2+与YM101结合具有协同抗肿瘤作用，有效控制肿瘤生长，延长荷瘤小鼠的生存期。这种新颖的鸡尾酒策略有可能成为炎症和非炎症肿瘤的通用方案。这种标准化的 TME 和重振抗肿瘤免疫力有助于联合疗法的优越抗肿瘤效果。Mn2+与YM101结合具有协同抗肿瘤作用，有效控制肿瘤生长，延长荷瘤小鼠的生存期。这种新颖的鸡尾酒策略有可能成为炎症和非炎症肿瘤的通用方案。