College of Basic Medicine and Biological Sciences, Medical Department, Soochow University, Suzhou 215123, Jiangsu, China.
College of Basic Medicine and Biological Sciences, Medical Department, Soochow University, Suzhou 215123, Jiangsu, China; Institute of Blood and Marrow Transplantation, Department of Hematology, Collaborative Innovation Center of Hematology, The First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu, China.
Clin Immunol. 2023 Aug;253:109685. doi: 10.1016/j.clim.2023.109685. Epub 2023 Jul 3.
Inducing tumor-specific T cell responses and regulating suppressive tumor microenvironments have been a challenge for effective tumor therapy. CpG (ODN), the Toll-like receptor 9 agonist, has been widely used as adjuvants of cancer vaccines to induce T cell responses. We developed a novel adjuvant to improve the targeting of lymph nodes. CpG were modified with lipid and glycopolymers by the combination of photo-induced RAFT polymerization and click chemistry, and the novel adjuvant was termed as lipid-glycoadjuvant@AuNPs (LCpG). OVA protein was used as model antigen and melanoma model was established to test the immunotherapy effect of the adjuvant. In tumor model, the antitumor effect and mechanism of LCpG on the response of CTLs were examined by flow cytometry and cell cytotoxicity assay. The effects of LCpG on macrophage polarization and Tregs differentiation in tumor microenvironment were also studied by cell depletion assay and cytokine neutralization assay. We also tested the therapeutic effect of the combination of the adjuvant and anti-PD-1 treatment. LCpG could be rapidly transported to and retained longer in the lymphoid nodes than unmodified CpG. In melanoma model, LCpG controlled both primary tumor and its metastasis, and established long-term memory. In spleen and tumor draining lymphoid nodes, LCpG activated tumor-specific Tc1 responses, with increased CD8+ T-cell proliferation, antigen-specific Tc1 cytokine production and specific-tumor killing capacity. In tumor microenvironments, antigen-specific Tc1 induced by the LCpG promoted CTL infiltration, skewed tumor associated macrophages to M1 phenotype, regulated Treg and induced proinflammatory cytokines production in a CTL-derived IFN-γ-dependent manner. In vivo cell depletion and adoptive transfer experiments confirmed that antitumor activity of LCpG included vaccine was mainly dependent on CTL-derived IFN-γ. The anti-tumor efficacy of LCpG was dramatically enhanced when combined with anti-PD1 immunotherapy. LCpG was a promising adjuvant for vaccine formulation which could augment tumor-specific Tc1 activity, and regulate tumor microenvironments.
诱导肿瘤特异性 T 细胞反应和调节抑制性肿瘤微环境一直是有效肿瘤治疗的挑战。CpG（ODN），即 Toll 样受体 9 激动剂，已被广泛用作癌症疫苗的佐剂，以诱导 T 细胞反应。我们开发了一种新型佐剂来提高淋巴结的靶向性。CpG 通过光引发 RAFT 聚合和点击化学的组合进行脂质和糖聚合物修饰，新型佐剂被命名为脂质-糖佐剂@AuNPs（LCpG）。OVA 蛋白被用作模型抗原，建立黑色素瘤模型以测试佐剂的免疫治疗效果。在肿瘤模型中，通过流式细胞术和细胞毒性测定来检查 LCPG 对 CTL 反应的抗肿瘤作用和机制。通过细胞耗竭测定和细胞因子中和测定研究了 LCPG 对肿瘤微环境中巨噬细胞极化和 Treg 分化的影响。我们还测试了佐剂与抗 PD-1 治疗相结合的治疗效果。LCpG 比未修饰的 CpG 能更快地转运到淋巴结并在淋巴结中保持更长时间。在黑色素瘤模型中，LCpG 控制了原发性肿瘤及其转移，并建立了长期记忆。在脾和肿瘤引流淋巴结中，LCpG 激活了肿瘤特异性 Tc1 反应，增加了 CD8+T 细胞增殖、抗原特异性 Tc1 细胞因子产生和特异性肿瘤杀伤能力。在肿瘤微环境中，LCpG 诱导的抗原特异性 Tc1 促进 CTL 浸润，使肿瘤相关巨噬细胞向 M1 表型倾斜，调节 Treg 并以 CTL 衍生的 IFN-γ依赖性方式诱导促炎细胞因子的产生。体内细胞耗竭和过继转移实验证实，LCpG 的抗肿瘤活性主要依赖于 CTL 衍生的 IFN-γ。当与抗 PD1 免疫治疗联合使用时，LCpG 的抗肿瘤疗效显著增强。LCpG 是一种有前途的疫苗佐剂，可增强肿瘤特异性 Tc1 活性，并调节肿瘤微环境。
