Modified CAR T cells targeting membrane-proximal epitope of mesothelin enhances the antitumor function against large...

Area of Science:

• Immunotherapy
• Oncology
• Molecular Biology

Background:

• Mesothelin (MSLN) is a promising target antigen for chimeric antigen receptor (CAR) T-cell therapy.
• Epitope selection on MSLN is critical for effective CAR T-cell therapy development.

Purpose of the Study:

• To compare the efficacy of two novel CAR T-cell therapies targeting different MSLN regions.
• To evaluate CAR T-cell responses against MSLN-positive solid tumors.

Main Methods:

• Constructed meso1 CAR (membrane-distal) and meso3 CAR (membrane-proximal) T cells using a modified piggyBac transposon system.
• Assessed CAR T-cell activation, cytokine production (IL-2, TNF-α, IFN-γ), and cytotoxic activity in vitro and in vivo.
• Utilized real-time cell analyzer, 3D spheroid models, and NSG mice models for gastric and ovarian cancers.

Main Results:

• Meso3 CAR T cells exhibited enhanced activation (CD107α expression) and cytokine release compared to meso1 CAR T cells.
• Meso3 CAR T cells demonstrated superior killing of MSLN-expressing cancer cells in vitro and in 3D models.
• In vivo studies showed meso3 CAR T cells mediated stronger antitumor responses in gastric cancer models and inhibited ovarian tumor growth.

Conclusions:

• Meso3 CAR T-cell therapy targeting the membrane-proximal region of MSLN is more effective than meso1 CAR T-cell therapy.
• Meso3 CAR T-cell therapy represents a superior immunotherapy strategy for treating MSLN-positive solid tumors.