Design and Characterization of an "All-in-One" Lentiviral Vector System Combining Constitutive Anti-G_D2 CAR...

Area of Science:

• Immunology
• Biotechnology
• Oncology

Background:

• Chimeric antigen receptor (CAR) T cells have limited efficacy in solid tumors due to immunosuppressive tumor microenvironments and poor CAR T cell function.
• Next-generation CAR T cells, termed TRUCKs (T cells redirected for universal cytokine-mediated killing), secrete cytokines upon CAR activation to overcome these limitations.
• Current TRUCK engineering often requires multiple vectors, complicating production.

Purpose of the Study:

• To develop an efficient "all-in-one" lentiviral vector system for TRUCK production.
• To enable inducible cytokine secretion linked to CAR activation for improved T cell function.
• To simplify the application of TRUCK-modified T cells in solid tumor immunotherapy.

Main Methods:

• Engineered a modular lentiviral vector system for constitutive CAR expression and inducible transgene expression driven by the NFAT promoter.
• Utilized a GD2-specific CAR to target GD2+ tumor cells.
• Co-cultivated engineered T cells with primary human GD2+ tumor cells to assess cytokine secretion and effector functions.

Main Results:

• The "all-in-one" vector system successfully enabled inducible cytokine secretion (IL-12 or IL-18) upon CAR activation by GD2+ target cells.
• Demonstrated tight linkage between CAR-specific activation and transgene expression, further enhanced by a modified NFATsyn promoter.
• Observed enhanced effector cell properties and increased monocyte recruitment in response to TRUCK-secreted cytokines.

Conclusions:

• The developed lentiviral system simplifies TRUCK production and enhances their therapeutic potential for solid tumors.
• Inducible cytokine secretion via TRUCKs can overcome tumor microenvironment-mediated suppression.
• This approach holds promise for improving CAR T cell therapy efficacy against solid malignancies.