Non-α-biased IL-2 enhances both intratumoral and subcutaneous CpG/α-OX40 therapy, unleashing systemic antitumor immunity in mice

作者：Kejie Huang, Xiaobo Ding, Xuehuan Wen, Chaoming Huang, Yan Chen, Xujie Zhou, Leying Zhou, Ying He, Zhixiang Bai, Chunhong Zhang, Yi Jin, Jianmin Li, Zhenghua Fei, wenfeng li, C. Chen · 发表于：Journal for ImmunoTherapy of Cancer · 年份：2025 · DOI：10.1136/jitc-2025-012336 · 被引用次数：1 · 研究领域：Immune cells in cancer、Immune Response and Inflammation、Immunotherapy and Immune Responses

Background The CpG/α-OX40 in situ vaccine strategy has shown efficacy in immune-hot tumors but remains ineffective in immune-cold tumors possibly due to immunosuppressive microenvironments characterized by myeloid-derived suppressor cells (MDSCs) infiltration and T cell exclusion. This study aims to investigate the antitumor effect of non-α-biased IL-2 combined with CpG/α-OX40 in mice. Methods Using 4T1 breast cancer and CT26 colon cancer models, we evaluated the antitumor effects of combining CpG/α-OX40 with a non-α-biased IL-2 variant via both intratumoral and subcutaneous routes. Tumor growth, lung metastasis, immune profile, and in vitro function analysis were assessed through flow cytometry, transcriptomic analysis, and T cell suppression assays. Results The combination therapy significantly inhibited primary and distant tumor growth and reduced lung metastasis in 4T1 models. Subcutaneous administration induced complete tumor regression in 55% (5/9) of CT26-tumor-bearing mice and conferred durable tumor-specific memory. Mechanistically, the treatment enhanced CD8 + T cell activation, metabolic reprogramming, and IFN-γ production, while suppressing MDSC expansion and immunosuppressive function. Conclusions These findings demonstrate that non-α-biased IL-2 synergizes with CpG/α-OX40 to overcome microenvironmental immunosuppression and achieve systemic antitumor immunity via a subcutaneous route, offering a translatable combinatorial strategy for immune-cold tumors.