Lymphotropic Virotherapy Engages DC and High Endothelial Venule Inflammation to Mediate Cancer In Situ Vaccination

Intratumor (IT) inoculation of the rhino:poliovirus chimera, PVSRIPO, yielded objective radiographic responses with long-term survival in 20% of patients with recurrent glioblastoma (rGBM). PVSRIPO infects dendritic cells (DCs) and sets up non-cytopathogenic viral (v)RNA replication, which triggers sustained type-I IFN (IFN-I) signaling and antitumor T cell priming. Here we identify IFN-I signaling in glioma-draining cervical lymph nodes (cLN) as a mediator of polio virotherapy. Transient IFN-I signaling after IT therapy was rescued by cervical perilymphatic injection (CPLI) of PVSRIPO, targeting cLN directly. Dual-site (IT+CPLI) PVSRIPO induced profound inflammatory reprogramming of cLN, enhanced vRNA replication and IFN-I signaling in DCs and High Endothelial Venules (HEV), augmented anti-glioma efficacy in mice, and was associated with T cell activation in rGBM patients. A Ph2 clinical trial of IT+CPLI PVSRIPO is ongoing (NCT06177964). This work implicates the lymphatic system as a novel virotherapy target and demonstrates the CPLI concept to complement brain tumor immunotherapy. hCD155tg C57BL/6 mice were implanted with CT2A glioma cells and treated with immunotherapeutic human rhinovirus-poliovirus chimera PVSRIPO in one of four combinations of mock or RIPO intratumorally (IT, 7 and 10 days post implantation) and paralymphatically (CPLI, 10 and 13 days post implantation) with deep and superficial cervical lymph nodes harvested for RNA sequencing.

瘤内接种（Intratumor, IT）鼻病毒-脊髓灰质炎病毒嵌合体（rhino:poliovirus chimera, PVSRIPO），可在20%的复发性胶质母细胞瘤（recurrent glioblastoma, rGBM）患者中诱导客观影像学应答并实现长期生存。PVSRIPO可感染树突状细胞（dendritic cells, DC），启动非细胞致病性病毒RNA复制，进而触发持续的I型干扰素（type-I IFN, IFN-I）信号通路激活与抗肿瘤T细胞致敏。本研究鉴定出胶质瘤引流颈淋巴结（glioma-draining cervical lymph nodes, cLN）中的I型干扰素信号是脊髓灰质炎溶瘤病毒疗法的关键介导因子。瘤内治疗后短暂激活的I型干扰素信号，可通过直接靶向cLN的颈淋巴管周围注射（cervical perilymphatic injection, CPLI）PVSRIPO得以挽救。双部位给药（IT+CPLI）的PVSRIPO可诱导cLN发生显著的炎症重编程，增强DC与高内皮微静脉（High Endothelial Venules, HEV）中的病毒RNA复制及I型干扰素信号通路，提升小鼠的抗胶质瘤疗效，且与rGBM患者的T细胞活化状态相关。目前针对IT+CPLI PVSRIPO的II期临床试验（Phase 2 clinical trial）正在开展（临床试验编号：NCT06177964）。本研究证实淋巴系统是一类新型溶瘤病毒治疗靶点，并验证了CPLI策略可作为脑肿瘤免疫治疗的有效补充手段。本研究使用hCD155转基因C57BL/6小鼠（hCD155tg C57BL/6 mice），在其颅内植入CT2A胶质瘤细胞（CT2A glioma cells），随后采用四种组合方案进行治疗：分别为模拟处理或免疫治疗性人鼻病毒-脊髓灰质炎病毒嵌合体PVSRIPO瘤内注射（IT，于植入后第7、10天给药）以及旁淋巴途径注射（CPLI，于植入后第10、13天给药），最终采集深浅颈淋巴结进行RNA测序（RNA sequencing）。