PO.CL05.13 · 临床研究
一种 Cxcl10 mRNA-LNP 佐剂在黑色素瘤模型中增强免疫检查点抑制剂应答
A Cxcl10 mRNA-LNP adjuvant enhances immune checkpoint inhibitor responses in melanoma models
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
免疫疗法已成为黑色素瘤治疗的标准治疗方案；然而，约 50% 的患者对免疫疗法耐药。这可能由免疫抑制性肿瘤微环境所致，此类微环境中免疫细胞（尤其是 T 细胞）浸润较低。T 细胞浸润高的肿瘤对免疫检查点治疗表现出更好的应答，因此调节肿瘤微环境以增强 T 细胞募集和激活成为一项关键的未满足需求。在本研究中，我们假设使用 mRNA 编码的"基因佐剂"能够增加 T 细胞向肿瘤微环境的浸润并改善免疫疗法应答。趋化因子 CXCL10 在 T 细胞募集和激活中发挥关键作用，通过活化 T 细胞表达的 CXCR3 受体进行信号传导。与该机制一致，对黑色素瘤患者血清样本的分析显示，免疫疗法应答者的 Cxcl10 水平显著高于无应答者。为直接增强 CXCL10，我们开发了一种编码 Cxcl10 的 mRNA 脂质纳米颗粒（Cxcl10 LNP）。在 C57BL/6J 野生型小鼠肌肉注射 Cxcl10 LNP 后，观察到血清和腹股沟淋巴结中 CXCL10 水平显著升高。我们的数据显示，肌肉注射 Cxcl10 LNP 显著减小了已建立的皮下 B16F10 小鼠黑色素瘤肿瘤的体积。经流式细胞术和活体成像评估，Cxcl10 LNP 治疗在 48 小时时导致肿瘤微环境内 CD8+ T 细胞显著增加。表型分析进一步揭示，肌肉注射 Cxcl10 LNP 后 48 小时，TRP-2 肿瘤特异性 CD8+ T 细胞和 CD107a+ 细胞毒性效应 CD8+ T 细胞显著增加。当与抗 PD-1 和抗 CTLA-4 双重免疫检查点抑制剂抗体联合使用时，Cxcl10 LNP 改善了长期生存并显著降低了皮下肿瘤生长，第 100 天时有 20% 的小鼠无肿瘤。此外，在我们的自发性转移性黑色素瘤模型中，小鼠在原发肿瘤切除后 24 小时接受 Cxcl10 LNP，随后接受抗 PD-1 和抗 CTLA-4 双重免疫检查点抑制剂，共 3 剂。用 Cxcl10 LNP 作为免疫检查点抑制剂的佐剂显著减少了肺和淋巴结转移，80% 的小鼠未检测到转移。这些发现表明，使用 Cxcl10 LNP 是一种有效的基因佐剂，能够增强 CD8+ T 细胞浸润和细胞毒性功能，从而改善免疫检查点抑制剂的疗效并减轻肿瘤负荷和转移。
查看英文原文 English abstract
Immunotherapies have become standard of care in the treatment of melanoma; however, about 50% of patients are immunotherapy resistant. This can be caused by an immunosuppressive tumor microenvironment that has a low infiltration of immune cells, especially T cells. Tumors with high T cell infiltration demonstrate better responses to immune checkpoint therapy, making modulation of the tumor microenvironment to enhance T cell recruitment and activation a critical unmet need. In this study, we hypothesize that using an mRNA encoded “genetic adjuvant” can increase the infiltration of T cells into the tumor microenvironment and improve immunotherapy response. The chemokine CXCL10 plays a key role in T cell recruitment and activation, signaling via the CXCR3 receptor expressed by activated T cells. Consistent with this mechanism, analysis of melanoma patient serum samples showed significantly higher Cxcl10 levels in immunotherapy responders compared to non-responders. To directly enhance CXCL10, we developed a Cxcl10-encoded mRNA lipid nanoparticle (Cxcl10 LNP). A significant increase in CXCL10 levels in the sera and inguinal lymph nodes of C57BL/6J wild-type mice was observed post intramuscular administration of Cxcl10 LNP. Our data shows that intramuscular injection of Cxcl10 LNP significantly reduced the volume of established subcutaneous B16F10 murine melanoma tumors. Cxcl10 LNP treatment lead to a significant increase of CD8+ T cells within the tumor microenvironment at 48 hours assessed by flow cytometry and intravital imaging. Phenotypic profiling further revealed significant increases of TRP-2 tumor specific CD8+ T cells and CD107a+ cytotoxic effector CD8+ T cells 48hrs post intramuscular administration of Cxcl10 LNP. When combined with dual anti-PD-1 and anti-CTLA-4 immune checkpoint inhibitor antibodies, Cxcl10 LNP improved long-term survival and significantly decreased subcutaneous tumor growth, with 20% of mice tumor-free at day 100. Moreover, in our spontaneous metastatic melanoma model, mice received Cxcl10 LNP 24h post primary tumor resection followed by dual anti-PD-1 and anti-CTLA-4 immune checkpoint inhibitors for a total of 3 doses. Adjuvating immune checkpoint inhibitors with Cxcl10 LNP significant reduced lung and lymph node metastasis, with 80% of mice showing no detectable metastases. These findings demonstrate that using Cxcl10 LNP is an effective genetic adjuvant that enhances CD8+ T cell infiltration and cytotoxic function, resulting in improved efficacy of immune checkpoint inhibitors and reducing tumor burden and metastases.
利益披露 Disclosure
K. M. Landreth, None..
K. Lee, None..
E. Sen Kilic, None..
J. Chapman, None..
M. Garland-Kledzik, None..
F. Damron, None..
T. W. Liu, None.