Multifunctional mRNA-Based CAR T Cells Display Promising Antitumor Activity Against Glioblastoma.

Area of Science:

• Oncology
• Immunotherapy
• Molecular Biology

Background:

• Current chimeric antigen receptor (CAR) T-cell therapies for glioblastoma have limited efficacy due to persistent gene modification challenges.
• These limitations include restricted transgene capacity, lengthy manufacturing, and potential for severe off-tumor toxicities.
• Messenger RNA (mRNA)-based T-cell modification presents a promising, rapid, and cost-effective alternative but remains underexplored for glioblastoma.

Purpose of the Study:

• To evaluate the efficacy of mRNA-based multifunctional T cells engineered with a multitargeting natural killer group 2D (NKG2D) receptor and the cytokines IL12 and IFNα2 against glioblastoma.
• To compare the anti-glioma activity of these multifunctional T cells against T cells expressing only the CAR or cytokines alone.
• To investigate the underlying mechanisms and translational potential in patient-derived glioblastoma models.

Main Methods:

• Generation of mouse and human mRNA-based T cells coexpressing a multitargeting NKG2D CAR, IL12, and IFNα2.
• In vitro and in vivo assessment of anti-glioma activity in orthotopic immunocompetent mouse glioma models.
• Ex vivo immune phenotyping, cytokine profiling, and RNA sequencing to analyze the tumor microenvironment and T-cell exhaustion.
• Image-based single-cell analyses in patient glioblastoma samples to evaluate translational potential.

Main Results:

• Multifunctional CAR T cells demonstrated significantly enhanced anti-glioma activity compared to CAR T cells or cytokine-only T cells, both in vitro and in vivo.
• The coexpression of IL12 and IFNα2 alongside the CAR promoted a proinflammatory tumor microenvironment and reduced T-cell exhaustion.
• Human mRNA-based multifunctional NKG2D CAR T cells showed strong anti-glioma activity in complex patient glioblastoma microenvironments, unlike T cells with single modifications.

Conclusions:

• mRNA-based multifunctional CAR T cells coexpressing NKG2D CAR, IL12, and IFNα2 represent a potent therapeutic strategy against glioblastoma.
• This approach overcomes limitations of traditional CAR T-cell therapies, offering improved safety and efficiency.
• The findings provide a strong rationale for advancing mRNA-based multifunctional CAR T cells into clinical trials for malignant brain tumors.