MDSC: a new potential breakthrough in CAR-T therapy for solid tumors.

Area of Science:

• Immunology
• Oncology
• Cell Therapy

Background:

• Chimeric antigen receptor T (CAR-T) cell therapy shows success in blood cancers but struggles with solid tumors.
• The immunosuppressive tumor microenvironment (TME), largely driven by myeloid-derived suppressor cells (MDSCs), hinders CAR-T efficacy in solid tumors.
• MDSCs promote tumor progression, metastasis, and suppress T cell activity within the TME.

Purpose of the Study:

• To review the detrimental effects of MDSCs on CAR-T cell therapy in solid tumors.
• To summarize current and emerging therapeutic strategies for targeting MDSCs to enhance CAR-T immunotherapy.
• To highlight the potential of MDSC-targeted approaches for improving CAR-T treatment outcomes in solid tumors.

Main Methods:

• Review of preclinical and clinical studies on MDSCs and CAR-T cell therapy.
• Analysis of MDSC immunosuppressive mechanisms within the TME.
• Categorization of therapeutic strategies targeting MDSCs in combination with CAR-T therapy.

Main Results:

• MDSCs significantly impede CAR-T cell function and contribute to tumor growth and metastasis.
• Various strategies are effective in preclinical models, including small molecule inhibitors, antibodies, and modified CAR-T/NK cells.
• Targeting MDSCs can involve direct antigen targeting, combination therapies, or indirect modulation of the TME.

Conclusions:

• Targeting MDSCs is a promising approach to overcome the immunosuppressive TME and enhance CAR-T efficacy against solid tumors.
• Multiple strategies exist for MDSC modulation, offering diverse options for therapeutic development.
• Future clinical applications are expected to benefit from the integration of MDSC-targeting strategies into CAR-T cell therapy for solid tumors.