Targeting HLA-E in Lung Cancer: The Therapeutic Potential of IRF5-Engineered M1-Macrophage-Derived Exosomes.

Immunotherapy is a pivotal approach in the treatment of lung cancer. Although HLA-E is a potential target for tumor immunotherapy, its role in lung cancer remains unclear. Previous studies have identified the transcription factor IRF5 as a characteristic gene of M1-like macrophages, highlighting its crucial role in promoting antitumor immune responses. In this study, we developed an engineered M1-like macrophage exosomes expressing IRF5 (IRF5 M1-exos) and demonstrated their ability to inhibit proliferation, migration, and invasion of lung cancer cells. Moreover, our experiments using a nude mouse model revealed that IRF5 M1-exos exerted potent therapeutic effects by effectively suppressing tumor growth. Notably, the mechanism by which IRF5 exerts its antitumor function through HLA-E regulation in lung cancer has not been fully elucidated. Here, we identified HLA-E as a downstream target gene of IRF5 and demonstrated that the overexpression of HLA-E can counteract the tumor-promoting effects induced by si-IRF5 M1-exos. These results suggest that M1 macrophage-derived exosomes, enriched with the transcription factor IRF5, exhibit potent antitumor activity by up-regulating HLA-E in lung cancer cells. Therefore, IRF5 M1-exos represent an attractive therapeutic strategy for lung cancer.