Human 3D Ovarian Cancer Models Reveal Malignant Cell-Intrinsic and -Extrinsic Factors That Influence CAR T-cell...

Area of Science:

• Immunology
• Oncology
• Biotechnology

Background:

• Chimeric antigen receptor (CAR) T-cell therapy shows promise for solid tumors, but in vitro preclinical testing often uses simplified models.
• Tumor microenvironment complexity, including cell-cell and cell-matrix interactions, significantly impacts CAR T-cell efficacy.
• Developing more complex in vitro models is crucial for understanding resistance mechanisms and advancing CAR T-cell therapies.

Purpose of the Study:

• To investigate the modulation of CAR T-cell activity by malignant cells and fibroblasts in increasingly complex human three-dimensional (3D) in vitro models.
• To elucidate mechanisms of resistance to CAR T-cell killing in high-grade serous ovarian cancer.
• To evaluate the utility of advanced 3D models for preclinical screening of CAR T-cell constructs.

Main Methods:

• Utilized human 3D cell models of varying complexity, incorporating ovarian cancer cells, CAR T cells (MUC1 and TnMUC1), and primary human fibroblasts.
• Investigated the role of death receptor signaling (TNFα) and chemokine signaling (CCL2/CCR2/4) in CAR T-cell mediated killing.
• Employed collagen gel cultures to mimic the extracellular matrix and developed a vascularized microfluidic device for more physiological testing.

Main Results:

• Malignant ovarian cancer cells exhibited intrinsic resistance to CAR T-cell killing due to defective TNFα signaling.
• Fibroblasts enhanced CAR T-cell killing of resistant cancer cells via CCL2-mediated activation of CAR T cells.
• A dense extracellular matrix (collagen gels) impeded CAR T-cell activity through TGFβ, while a microfluidic device improved CAR T-cell penetration and killing.

Conclusions:

• Complex 3D in vitro models effectively uncover resistance mechanisms in solid tumors, such as those involving the tumor microenvironment.
• These models facilitate the evaluation of cell-cell and cell-matrix interactions impacting CAR T-cell therapy.
• Advanced 3D models can accelerate the preclinical development and optimization of CAR T-cell therapies for solid tumors.