基于工程化慢病毒载体的体内靶向递送系统实现CAR T和NK细胞的原位生成

CAR T细胞疗法虽在B细胞恶性肿瘤治疗中取得突破，但自体化生产流程复杂、成本高昂且需淋巴清除预处理，限制了患者可及性。本研究开发了搭载第二代去靶向融合蛋白(Gen 2.1 Fusogen)和CD7靶向scFv的慢病毒平台INT2104，通过单次静脉注射即可在灵长类模型中生成CAR20+ T/NK细胞并清除CD20+ B细胞，为开发"即用型"基因疗法提供新策略。

　　

CAR T细胞疗法 revolutionized the treatment landscape for B-cell malignancies, yet its widespread application faces significant hurdles. The current autologous approach requires complex ex vivo manufacturing, substantial financial investment, and preconditioning chemotherapy that often involves toxic lymphodepletion regimens. These barriers disproportionately limit access for patients in resource-constrained settings. Addressing these challenges requires innovative solutions that can bypass the need for cell extraction and laboratory manipulation while maintaining therapeutic efficacy.

In this groundbreaking study published in Molecular Therapy, researchers developed INT2104 - an engineered lentiviral vector platform featuring two key innovations: a detargeted Gen 2.1 Fusogen to enhance safety and a membrane-bound CD7-targeting scFv (CD7 Binder) for precise in vivo delivery. This system was designed to deliver a CAR20 transgene directly to CD7⁺ immune cells in living organisms, effectively transforming the host's own T and NK cells into tumor-fighting agents without requiring lymphodepleting pretreatment.

The research employed several pivotal methodologies: 1) Lentiviral vector engineering incorporating fusogen modifications and targeting moieties; 2) In vivo delivery assessment using mouse and cynomolgus macaque models; 3) Flow cytometry-based tracking of CAR⁺ cell generation; 4) Functional evaluation through CD20⁺ B cell depletion monitoring.

Key findings emerged through systematic investigation:

1. Platform Design demonstrated successful integration of the detargeted fusogen with CD7-targeting capability, creating a stable delivery system for the CAR20 transgene.
2. In Vivo Performance showed that intravenous administration led to CAR expression in both CD4⁺ and CD8⁺ T cell subsets as well as NK cells.
3. Therapeutic Effect manifested as significant depletion of CD20⁺ B cells, confirming functional activity of the generated CAR cells.
4. Safety Profile observations suggested the approach may avoid toxicity associated with conventional lymphodepletion regimens.

The study concludes that INT2104 represents a paradigm-shifting approach to CAR therapy by enabling in vivo generation of effector cells through targeted genetic delivery. This innovation could dramatically simplify treatment protocols, reduce costs, and expand access to cellular immunotherapy. Particularly noteworthy is the dual generation of both CAR T and CAR NK cells, which may provide complementary anti-tumor mechanisms. The platform's modular design also suggests potential applicability beyond CD20-targeting, possibly adaptable to other therapeutic transgenes. These findings position lentiviral vector engineering as a powerful strategy for developing next-generation, off-the-shelf genetic medicines.