Data Sheet 1_Intratumoral delivery of mRNA encoding the endogenous TLR2/6 agonist UNE-C1 induces immunogenic cell death and enhances antitumor activity.docx

IntroductionRecent investigations have highlighted the intratumoral administration of Toll-like receptor (TLR) ligands as a promising approach to initiate localized immune responses and enhance antitumor immunity. However, the clinical application of these ligands is limited by their rapid dissemination from the tumor microenvironment, raising concerns about reduced effectiveness and systemic toxicity.MethodsTo address these challenges, our study focused on the intratumoral delivery of mRNA encoding UNE-C1, a TLR2/6 ligand known for its efficacy and low toxicity profile. We explored the potential of UNE-C1 to induce immunogenic cell death (ICD) through autocrine mechanisms, facilitated by the release of damage-associated molecular patterns (DAMPs) triggered by TLR2 activation.ResultsOur findings indicate that sensitivity to UNE-C1-induced cell death is dependent on the expression levels of TLR2 and the Fas-associated death domain (FADD) in cancer cells. Furthermore, we investigated the paracrine activation of dendritic cells (DCs) by UNE-C1 via TLR2 signaling, which primes a CD8+ T cell response essential for tumor regression.DiscussionOur results advocate for the intratumoral delivery of UNE-C1 via mRNA therapy as a promising strategy for innovative antitumor treatments.

近年来，对肿瘤内注射Toll样受体（TLR）配体的研究凸显了其作为一种启动局部免疫反应并增强抗肿瘤免疫的潜在方法。然而，这些配体在肿瘤微环境中的快速扩散限制了其临床应用，引发了关于其疗效降低和全身毒性的担忧。本研究旨在解决这些挑战，聚焦于肿瘤内注射编码UNE-C1的mRNA，UNE-C1是一种已知具有高效能和低毒性特征的TLR2/6配体。我们探讨了UNE-C1通过自分泌机制诱导免疫原性细胞死亡（ICD）的潜力，该机制通过TLR2激活触发的损伤相关分子模式（DAMPs）的释放得到促进。研究结果指出，对UNE-C1诱导的细胞死亡的敏感性取决于肿瘤细胞中TLR2和Fas相关死亡结构域（FADD）的表达水平。此外，我们还研究了UNE-C1通过TLR2信号通路介导的树突状细胞（DCs）的旁分泌激活，这能够启动CD8+ T细胞反应，这对于肿瘤消退至关重要。讨论部分，我们的研究结果支持通过mRNA疗法将UNE-C1在肿瘤内注射作为一种创新抗肿瘤治疗策略的可行性。