Herpes Virus Entry Mediator Costimulation Signaling Enhances CAR T-cell Efficacy Against Solid Tumors Through...

Area of Science:

• Immunology
• Oncology
• Cellular Therapy

Background:

• Chimeric antigen receptor (CAR) T cells, utilizing 4-1BB and CD28 costimulatory domains, are effective against hematologic cancers but limited in solid tumors.
• The herpes virus entry mediator (HVEM) is a costimulatory molecule with a unique signaling pathway.

Purpose of the Study:

• To investigate the efficacy of CAR T cells engineered with an HVEM costimulatory domain (HVEM-CAR T) for solid tumor treatment.
• To compare the anti-tumor activity and mechanisms of HVEM-CAR T cells against traditional 4-1BB-CAR T and CD28-CAR T cells.

Main Methods:

• In vitro assessment of cytokine release and cytotoxicity of HVEM-CAR T cells compared to 4-1BB-CAR T and CD28-CAR T cells.
• In vivo evaluation of therapeutic efficacy of HVEM-CAR T cells in mouse solid tumor models.
• Mechanistic studies to analyze T cell exhaustion, function, persistence, and metabolic activity in tumor tissues.

Main Results:

• HVEM-CAR T cells demonstrated superior cytokine release and cytotoxicity in vitro compared to 4-1BB-CAR T and CD28-CAR T cells.
• HVEM-CAR T cells exhibited enhanced therapeutic efficacy in preclinical mouse models of solid tumors.
• Mechanistic analysis revealed attenuated exhaustion, improved function, persistence, and metabolic activity in HVEM-CAR T cells within the tumor microenvironment.

Conclusions:

• The herpes virus entry mediator costimulatory domain significantly enhances the efficacy of CAR T cells against solid tumors.
• HVEM-CAR T cells offer a promising strategy to overcome the limitations of current CAR T-cell therapies in solid malignancies.
• Targeting HVEM signaling represents a novel avenue for improving CAR T-cell-based cancer immunotherapy.