Chimeric cytokine receptor enhancing PSMA-CAR-T cell-mediated prostate cancer regression

Area of Science:

• Immunotherapy
• Oncology
• Cellular Engineering

Background:

• Chimeric antigen receptor T (CAR-T) cell therapy shows high efficacy in blood cancers but struggles with solid tumors.
• Solid tumors present unique challenges, including immunosuppressive microenvironments, limiting CAR-T cell effectiveness.
• The inverted chimeric cytokine receptor (ICR) is a novel construct designed to enhance CAR-T cell function in challenging tumor microenvironments.

Purpose of the Study:

• To engineer CAR-T cells with an ICR to improve their efficacy against solid tumors.
• To evaluate the anti-tumor activity of PSMA-targeted CAR-T cells co-expressing ICR in prostate cancer models.
• To assess the potential of this enhanced CAR-T cell therapy for clinical translation.

Main Methods:

• Prostate specific membrane antigen (PSMA) was selected as the target antigen for CAR-T cells.
• An inverted chimeric cytokine receptor (ICR), comprising TGF-β extracellular domain and IL-7 receptor intracellular domain, was co-expressed on CAR-T cells.
• In vitro repeated target cell stimulation assays and in vivo mouse xenograft models were used to assess anti-tumor activity.

Main Results:

• Co-expression of ICR significantly enhanced the sustained anti-tumor capabilities of PSMA-CAR-T cells in vitro.
• In vivo experiments demonstrated that enhanced PSMA-CAR-T cells exhibited superior anti-tumor activity.
• The enhanced CAR-T cells prolonged survival time in xenograft and patient-derived xenograft (PDX) models of prostate cancer.

Conclusions:

• PSMA-CAR-T cells co-expressing ICR represent a promising new therapeutic strategy for prostate cancer.
• This enhanced CAR-T cell approach shows potential for overcoming limitations in solid tumor treatment.
• The findings support the translation of this improved CAR-T cell therapy into clinical settings.