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.