B7H6-specific chimeric antigen receptors lead to tumor elimination and host antitumor immunity

Area of Science:

• Immunotherapy
• Oncology
• Cellular Therapy

Background:

• Chimeric antigen receptor (CAR) T-cell therapies are effective against B-cell leukemia.
• Current CAR strategies require new targets for solid tumors and broader applicability.
• B7H6 is a promising target antigen due to its expression on various tumors and limited presence on normal tissues.

Purpose of the Study:

• To develop and evaluate a novel CAR T-cell therapy targeting the B7H6 antigen.
• To assess the efficacy of B7H6-specific CAR T-cells against hematologic and solid tumors.

Main Methods:

• Engineered CAR T-cells targeting the B7H6 ligand.
• In vitro co-culture assays with B7H6+ tumor cells and normal immune cells.
• In vivo studies using murine models of lymphoma and ovarian cancer.

Main Results:

• B7H6-specific CAR T-cells demonstrated potent cytotoxicity and interferon-γ secretion against B7H6+ tumor cells.
• Minimal self-reactivity was observed with immature dendritic cells and monocytes.
• Significant survival enhancement was observed in mice with B7H6+ lymphoma.
• Tumor burden was reduced in a murine ovarian cancer model.

Conclusions:

• B7H6-specific CAR T-cells are a viable therapeutic strategy for B7H6-expressing hematologic malignancies.
• This CAR strategy shows potential for treating B7H6-positive solid tumors.
• B7H6-targeted CAR T-cell therapy offers a broad applicability for multiple cancer types.