Radiation-induced CD200(+) tumor-associated macrophages suppress eosinophil-mediated antitumor immunity through CD200R signaling in hepatocellular carcinoma.

Radiotherapy induces CD200(+) tumor-associated macrophages via STING pathway, which suppress eosinophil-mediated antitumor immunity in hepatocellular carcinoma.

• Why it matters: Understanding how radiotherapy promotes immunosuppression is crucial to overcoming resistance and improving treatment outcomes in HCC patients.
• What they did: Single-cell RNA sequencing of postradiotherapy HCC specimens revealed that DNA damage activates STING in TAMs, leading to CD200 upregulation and recruitment of eosinophils through CCL3-CCR1 signaling.
• The result: Blocking CD200R restored eosinophil function, enhanced tumor control, and sensitized resistant tumors to radioimmunotherapy, highlighting CD200R blockade as a promising strategy to improve HCC treatment.