Topoisomerase IIα orchestrates secretion of IL-6 and IL-8 with human papillomavirus replication
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High-risk human papillomavirus (HPV) replication requires deregulation of host DNA damage response (DDR) and inflammatory pathways. DNA topoisomerase 2β (Top2β) was previously shown to promote HPV replication, while the function of its paralog Top2α in the viral life cycle remains unknown. Elevated levels of Top2α are consistently observed in cervical intraepithelial lesions and the related carcinomas, as well as in HPV-positive cell lines. Silencing Top2α with shRNA severely suppresses HPV genome maintenance and amplification, but in a DDR-independent manner. Instead, Top2α facilitates secretion of interleukin (IL)-6 and IL-8, which are necessary for HPV replication. Mechanistically, this manipulation is regulated by toll-like receptor 4 (TLR4). Top2α binds to the TLR4 promoter to transcriptionally induce TLR4 expression. Blockade of TLR4 signaling by the specific inhibitor TAK-242 significantly reduces the secreted IL-6/IL-8 levels and HPV replication. Overall, our results reveal a novel role of Top2α to shape the inflammatory microenvironment that benefits HPV replication, making it a promising therapeutic target for HPV-associated diseases.
IMPORTANCE
Human papillomaviruses (HPVs) are oncogenic pathogens responsible for many HPV-related diseases such as cervical cancer. HPV replication depends on the subversion of host cellular machineries, particularly pathways governing DNA damage response (DDR) and inflammation. However, the roles of enzymes that directly introduce DNA nicks or mediate strand rejoining remain poorly characterized. Here we highlight a novel role of DNA topoisomerase 2α (Top2α) in promoting HPV genome maintenance and amplification but in a DDR-independent manner. Unlike its previously studied paralog Top2β, Top2α supports HPV replication by driving the secretion of inflammatory molecules interleukin (IL)-6 and IL-8, which are critical for the viral genome persistence and copy number expansion. To our knowledge, this is the first evidence that a DDR-associated protein manipulates cytokine secretion, rather than expression, to support HPV replication. Furthermore, blocking toll-like receptor 4 (TLR4) activities significantly reduced Top2α-dependent IL-6/IL-8 secretion and impaired HPV replication. These findings establish Top2α as a crucial player in HPV pathogenesis, with a therapeutic potential for treating HPV-associated malignancies.
