IKZF3 deficiency potentiates chimeric antigen receptor T cells targeting solid tumors

Area of Science:

• Immunology
• Cancer Biology
• Cell Therapy

Background:

• Chimeric antigen receptor (CAR) T cell therapy shows success in hematological malignancies.
• Solid tumors remain a significant challenge for CAR T cell therapy efficacy.

Purpose of the Study:

• To investigate the role of transcription factor IKZF3 in CAR T cell function.
• To explore strategies for overcoming CAR T cell refractoriness in solid tumors.

Main Methods:

• Genetic modification of HER2-specific CAR T cells by knocking out IKZF3.
• In vitro and in vivo (xenograft model) assessment of CAR T cell killing efficacy.
• Analysis of T cell activation, proliferation, cytokine signaling, chemotaxis, and cytotoxicity using AlphaLISA and RNA-seq.

Main Results:

• IKZF3 knockout (KO) did not alter CAR expression or T cell differentiation.
• IKZF3 KO significantly enhanced cancer cell killing in vitro and in vivo.
• IKZF3 KO increased T cell activation, proliferation, and expression of genes related to cytokine signaling, chemotaxis, and cytotoxicity.
• Similar positive effects were observed with CD133-specific CAR T cells targeting glioblastoma.

Conclusions:

• Transcription factor IKZF3 is a key regulator of CAR T cell function in solid tumors.
• IKZF3 knockout represents a promising strategy to enhance CAR T cell therapy for solid tumors.
• This approach may offer a generalizable method for improving CAR T cell efficacy across various solid tumor types.