Intratumoral IL-12 delivery empowers CAR-T cell immunotherapy in a pre-clinical model of glioblastoma

Giulia Agliardi*, Anna Rita Liuzzi*, Alastair Hotblack, Donatella De Feo, Nicolás Núñez, Cassandra L. Stowe, Ekaterina Friebel, Francesco Nannini, Lukas Rindlisbacher, Thomas A. Roberts, Rajiv Ramasawmy, Iwan P. Williams, Bernard M. Siow, Mark F. Lythgoe, Tammy L. Kalber, Sergio A. Quezada, Martin A. Pule, Sonia Tugues, Karin Straathof§ and Burkhard Becher§. *These authors contributed equally § These authors contributed equally Corresponding authors: Burkhard Becher. E-Mail: [e-mail] Karin Straathof. E-Mail: [e-mail] Glioblastoma multiforme (GBM) is the most common and aggressive form of primary brain cancer, for which effective therapies are urgently needed. Chimeric antigen receptor (CAR)- based immunotherapy represents a promising therapeutic approach, but it is often impeded by highly immunosuppressive tumor microenvironments (TME). Here, in an immunocompetent, orthotopic GBM mouse model, we show that CAR-T cells targeting tumorspecific epidermal growth factor variant III (EGFRvIII) alone fail to control fully established tumors but, when combined with a single, locally delivered dose of IL-12, achieve durable antitumor responses. IL-12 not only boosts cytotoxicity of CAR-T cells, but also reshapes the TME, driving increased infiltration of proinflammatory CD4+ T cells, decreased numbers of regulatory T cells (Treg), and activation of the myeloid compartment. Importantly, the immunotherapy-enabling benefits of IL-12 are achieved with minimal systemic effects. Our findings thus show that local delivery of IL-12 may be an effective adjuvant for CAR-T cell therapy for GBM.Giulia Agliardi*、Anna Rita Liuzzi*、Alastair Hotblack、Donatella De Feo、Nicolás Núñez、Cassandra L. Stowe、Ekaterina Friebel、Francesco Nannini、Lukas Rindlisbacher、Thomas A. Roberts、Rajiv Ramasawmy、Iwan P. Williams、Bernard M. Siow、Mark F. Lythgoe、Tammy L. Kalber、Sergio A. Quezada、Martin A. Pule、Sonia Tugues、Karin Straathof§ 及 Burkhard Becher§。* 与 § 均表示作者贡献均等。通讯作者：Burkhard Becher，电子邮箱：[e-mail]；Karin Straathof，电子邮箱：[e-mail]。多形性胶质母细胞瘤（Glioblastoma multiforme, GBM）是最为常见且恶性程度最高的原发性脑肿瘤，目前亟需开发有效的治疗方案。基于嵌合抗原受体（chimeric antigen receptor, CAR）的免疫疗法是一种极具潜力的治疗策略，但往往会受到肿瘤微环境（tumor microenvironment, TME）高度免疫抑制的阻碍。本研究在免疫健全的原位胶质母细胞瘤小鼠模型中发现，仅靶向肿瘤特异性表皮生长因子受体变体III（epidermal growth factor variant III, EGFRvIII）的CAR-T细胞无法控制已完全建立的肿瘤，但联合单次局部递送的白细胞介素12（IL-12）时，可实现持久的抗肿瘤应答。IL-12不仅能够增强CAR-T细胞的细胞毒性，还可重塑肿瘤微环境，促进促炎性CD4+ T细胞浸润、减少调节性T细胞（regulatory T cell, Treg）的数量，并激活髓系细胞组分。值得注意的是，IL-12在赋予免疫治疗增益的同时，仅引发极轻微的全身不良反应。综上，本研究结果表明，局部递送IL-12或可成为胶质母细胞瘤CAR-T细胞治疗的有效佐剂。