在三阴性乳腺癌（TNBC）治疗中，淋巴细胞肿瘤浸润不足会显着阻碍免疫检查点抑制剂的疗效。我们之前已经证明，海南蛙皮中的宿主防御肽（HDP）海南烯宁-1（HN-1）通过未知的机制诱导乳腺癌细胞凋亡并启动抗肿瘤免疫。我们利用体外实验观察免疫原性细胞HN-1处理的TNBC细胞系中的死亡（ICD）指标，验证HN-1促进小鼠抗肿瘤免疫反应的小鼠肿瘤模型，以及患者来源的乳腺癌细胞的体外药敏试验以验证HN-1的抑制作用。HN-1在TNBC中诱导ICD，在此过程中释放损伤相关分子模式（DAMP），可以进一步增强抗肿瘤免疫反应。共培养上清液中白细胞介素2 (IL-2)、IL-12和干扰素γ的分泌水平增加，并且通过与HN-1预处理的TNBC细胞共培养，树突状细胞(DC)被激活。结果，HN-1 增加了携带 4T1 和 EMT6 肿瘤的小鼠模型中抗肿瘤免疫细胞（DC 和 T 淋巴细胞）的浸润。与此同时，调节性 T 细胞和骨髓源性抑制细胞受到抑制。此外，HN-1诱导DNA损伤，细胞质中双链DNA的释放显着增强，表明HN-1可能通过激活STING途径刺激ICD。 STING 的敲除抑制了 HN-1 诱导的 ICD。值得注意的是，HN-1 在三维培养条件下对患者来源的乳腺癌细胞表现出抑制作用。总的来说，我们的研究表明，HN-1 可以用作一种潜在的化合物，可以增强 TNBC 患者的免疫治疗效果。© 2024。作者。

In triple-negative breast cancer (TNBC) therapy, insufficient tumor infiltration by lymphocytes significantly hinders the efficacy of immune checkpoint inhibitors. We have previously demonstrated that Hainanenin-1 (HN-1), a host defense peptide (HDP) identified from Hainan frog skin, induces breast cancer apoptosis and boots anti-tumor immunity via unknown mechanism.We used in vitro experiments to observe immunogenic cell death (ICD) indicators in HN-1-treated TNBC cell lines, a mouse tumor model to verify HN-1 promotion of mice anti-tumor immune response, and an in vitro drug sensitivity test of patient-derived breast cancer cells to verify the inhibitory effect of HN-1.HN-1 induced ICD in TNBC in a process during which damage-associated molecular patterns (DAMPs) were released that could further increase the anti-tumor immune response. The secretion level of interleukin 2 (IL-2), IL-12, and interferon γ in the co-culture supernatant was increased, and dendritic cells (DCs) were activated via a co-culture with HN-1-pretreated TNBC cells. As a result, HN-1 increased the infiltration of anti-tumor immune cells (DCs and T lymphocytes) in the mouse model bearing both 4T1 and EMT6 tumors. Meanwhile, regulatory T cells and myeloid-derived suppressor cells were suppressed. In addition, HN-1 induced DNA damage, and double-strand DNA release in the cytosol was significantly enhanced, indicating that HN-1 might stimulate ICD via activation of STING pathway. The knockdown of STING inhibited HN-1-induced ICD. Of note, HN-1 exhibited inhibitory effects on patient-derived breast cancer cells under three-dimensional culture conditions.Collectively, our study demonstrated that HN-1 could be utilized as a potential compound that might augment immunotherapy effects in patients with TNBC.© 2024. The Author(s).