SHISA3 reprograms tumor-associated macrophages toward an M1 phenotype and enhances cancer immunotherapy

The main challenge for immune checkpoint blockade (ICB) therapy lies in immunosuppressive tumor microenvironment (TME). Repolarizing M2-like tumor-associated macrophages (TAMs) into inflammatory M1 phenotype is a promising strategy for cancer immunotherapy. Here, we found that the transmembrane protein SHISA3 is induced by DAMPs/PAMPs in macrophages via nuclear factor-κB (NF-κB) transcription factors, and SHISA3 forms complex with HSPA8 to reciprocally activates NF-κB signaling thus maintains M1 polarization of macrophages. Enforced expression of Shisa3 in TAMs increases their phagocytosis and antigen presentation abilities and promotes CD8+ T cell-mediated antitumor immunity. Local delivery of mRNA encoding Shisa3 enables therapy of cancer by dual effects on tumor cells and TAMs, and enhance the efficacy of PD-1 antibody. Taken together, our findings describe the role of SHISA3 in reprogramming TAMs that ameliorates cancer immunotherapy To find new molecules that regulate macrophage polarization, we performed transcriptomic analysis on early macrophages polarization induced by LPS for 0, 2, 4 hours. Comparative gene expression profiling analysis of RNA-seq data for BMDM induced by LPS for 0, 2, 4 hours. AAV-mediated Shisa3 overexpression in BMDMs were used for RNA-seq (AAV-Shisa3 BMDMs and AAV-GFP BMDMs) . *************************************************************** Submitter states that missing raw files are due to file loss. ***************************************************************

免疫检查点阻断（immune checkpoint blockade, ICB）疗法的核心挑战在于免疫抑制性肿瘤微环境（tumor microenvironment, TME）。将M2样肿瘤相关巨噬细胞（tumor-associated macrophages, TAMs）极化为促炎的M1表型，是癌症免疫治疗的极具前景的策略。本研究发现，损伤相关分子模式（damage-associated molecular patterns, DAMPs）/病原相关分子模式（pathogen-associated molecular patterns, PAMPs）可通过核因子-κB（nuclear factor-κB, NF-κB）转录因子在巨噬细胞中诱导跨膜蛋白SHISA3的表达；SHISA3与HSPA8形成复合物，可协同激活NF-κB信号通路，从而维持巨噬细胞的M1极化状态。在肿瘤相关巨噬细胞中强制过表达Shisa3，可增强其吞噬功能与抗原呈递能力，并促进CD8+ T细胞介导的抗肿瘤免疫。编码Shisa3的mRNA的局部递送可通过同时作用于肿瘤细胞与肿瘤相关巨噬细胞发挥癌症治疗作用，并增强抗PD-1抗体的治疗效果。综上，本研究阐明了SHISA3通过重编程肿瘤相关巨噬细胞以改善癌症免疫治疗的作用。为筛选调控巨噬细胞极化的新分子，我们对脂多糖（lipopolysaccharide, LPS）诱导0、2、4小时的早期极化巨噬细胞开展了转录组学分析。对脂多糖诱导0、2、4小时的骨髓来源巨噬细胞（bone marrow-derived macrophages, BMDMs）的RNA测序数据进行了比较基因表达谱分析。我们采用腺相关病毒（adeno-associated virus, AAV）介导Shisa3过表达的骨髓来源巨噬细胞进行RNA测序实验，实验分为AAV-Shisa3 BMDMs组与AAV-GFP BMDMs组。****************************************************************提交者说明，原始数据文件缺失系文件丢失所致。****************************************************************