Murad John P, Christian Lea, Rosa Reginaldo, Ren Yuwei, Lee Eric Hee Jun, Lopez Lupita S, Park Anthony K, Yang Jason, Trac Candi, Adkins Lauren N, Chang Wen-Chung, Martinez Catalina, June Carl H, Forman Stephen J, Ishihara Jun, Lee John K, Stern Lawrence A, Priceman Saul J
bioRxiv. 2025 May 19:2025.04.04.647304. doi: 10.1101/2025.04.04.647304.
CAR T cell efficacy in solid tumors is limited due in part to the immunosuppressive TME. To improve anti-tumor responses, we hypothesized that enabling CAR T cells to secrete bifunctional fusion proteins consisting of a cytokine modifier (e.g., TGFβtrap, IL15, or IL12) combined with an immune checkpoint inhibitor (e.g., αPDL1) will provide tumor localized immunomodulation to improve CAR T cell functionality. To that end, we engineered CAR T cells to secrete TGFβtrap, IL15, or IL12 molecules fused to αPDL1 scFv, and assessed in vitro functionality and in vivo safety and efficacy in prostate and ovarian cancer models. CAR T cells engineered with αPDL1-IL12 were superior in safety and efficacy compared to CAR T cells alone and to those engineered with αPDL1 fused with TGFβtrap or IL15. Further, αPDL1-IL12 engineered CAR T cells improved T cell trafficking and tumor infiltration, localized IFNγ production, TME modulation, and anti-tumor responses, with reduced systemic inflammation-associated toxicities. We believe our αPDL1-IL12 engineering strategy presents an opportunity to improve CAR T cell clinical efficacy and safety across multiple solid tumor types.
嵌合抗原受体（CAR）T细胞在实体瘤中的疗效有限，部分原因是免疫抑制性肿瘤微环境（TME）。为了改善抗肿瘤反应，我们假设使CAR T细胞分泌由细胞因子调节剂（如TGFβ陷阱、IL-15或IL-12）与免疫检查点抑制剂（如αPDL1）组成的双功能融合蛋白，将提供肿瘤局部免疫调节，以改善CAR T细胞功能。为此，我们对CAR T细胞进行工程改造，使其分泌与αPDL1单链抗体片段（scFv）融合的TGFβ陷阱、IL-15或IL-12分子，并在前列腺癌和卵巢癌模型中评估其体外功能以及体内安全性和疗效。与单独的CAR T细胞以及用与TGFβ陷阱或IL-15融合的αPDL1改造的CAR T细胞相比，用αPDL1-IL-12改造的CAR T细胞在安全性和疗效方面更优越。此外，用αPDL1-IL-12改造的CAR T细胞改善了T细胞转运和肿瘤浸润、局部IFNγ产生、TME调节以及抗肿瘤反应，同时降低了与全身炎症相关的毒性。我们相信，我们的αPDL1-IL-12工程策略为提高CAR T细胞在多种实体瘤类型中的临床疗效和安全性提供了一个机会。
