5-Aminolevulinic Acid Photodynamic Therapy treats HPV-associated diseases by promoting M1 macrophage polarization through STEAP3/p53/SLC7A11-mediated ferroptosis

BACKGROUND: Human papillomavirus (HPV) infection is a major driver of various malignancies, accounting for approximately 90% of cervical cancer cases and 70% of oropharyngeal cancer cases worldwide, yet therapies for persistent lesions remain limited. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) eliminates HPV-infected cells via reactive oxygen species (ROS)-mediated apoptosis and immune modulation, but its immune regulatory mechanisms remain undefined. METHODS: Macrophage polarization and ferroptosis were characterized through quantitative polymerase chain reaction (qPCR) analysis of phenotype markers, quantification of lipid peroxidation (MDA), ROS, and Bodipy-based fluorescence imaging. Transcriptomic profiling was employed to delineate ferroptosis-associated pathways underlying macrophage polarization. The STEAP3/p53/SLC7A11 axis was validated by Western blot (WB) and qPCR. The effects of macrophage-conditioned medium on HPV16-positive SiHa cells were evaluated using a CCK-8 assay and a Transwell migration assay. RESULTS: ALA-PDT triggered macrophage M1 polarization with upregulated pro-inflammatory markers and induced macrophage ferroptosis, evidenced by elevated ferroptosis markers. Transcriptomic analysis revealed activation of ferroptosis pathways (STEAP3, p53, SLC7A11) in PDT-treated macrophages. Ferrostatin-1, a ferroptosis inhibitor, reversed PDT-induced reduction of M1 polarization. Conditioned medium from PDT-treated macrophages significantly reduced the relative metabolic activity and migration of SiHa cells. CONCLUSION: ALA-PDT induces ferroptosis-dependent macrophage M1 polarization via the STEAP3/p53/SLC7A11 axis, potentiating macrophage-mediated elimination of HPV-infected cells. This ferroptosis-immunity interplay not only disrupts viral persistence but also provides a therapeutic paradigm to overcome HPV-driven immune suppression.