B7-H3 Negatively Modulates CTL-Mediated Cancer Immunity

Area of Science:

• Oncology
• Immunotherapy
• Cancer Research

Background:

• Anti-programmed death-1 (PD-1) immunotherapy offers survival benefits in non-small cell lung cancer (NSCLC).
• Treatment resistance necessitates alternative therapeutic strategies.
• B7-H3 is an immune-checkpoint molecule implicated in various cancers.

Purpose of the Study:

• To investigate B7-H3 expression in NSCLC patients undergoing anti-PD-1 therapy.
• To assess the therapeutic potential of combining anti-PD-1 and anti-B7-H3 therapies.
• This is the first study to evaluate B7-H3 expression in NSCLC treated with anti-PD-1 therapy.

Main Methods:

• Immunohistochemical analysis of B7-H3 expression in 82 NSCLC patients.
• Correlation analysis of B7-H3 expression with anti-PD-1 therapy response and CD8+ tumor-infiltrating lymphocytes (TILs).
• Evaluation of dual anti-B7-H3 and anti-PD-L1 antibody therapy in a murine cancer model; T-cell analysis via flow cytometry.

Main Results:

• B7-H3 was expressed in 74% of NSCLCs and linked to non-responsiveness to anti-PD-1 therapy.
• Anti-B7-H3 blockade demonstrated antitumor efficacy, increasing CD8+ TILs and restoring T-cell function.
• Combined anti-B7-H3 and anti-PD-L1 blockade yielded enhanced antitumor responses compared to single-agent therapy.

Conclusions:

• Tumor cell-expressed B7-H3 may evade CD8+ T-cell-mediated immune surveillance.
• Combination immunotherapy targeting B7-H3 and PD-1/PD-L1 presents a promising strategy for B7-H3-positive NSCLC.
• This approach warrants further investigation for improving outcomes in NSCLC patients.