Developing tools to study HPV16 in oropharyngeal tissues - Abstract Human papillomaviruses (HPVs) contribute to 5% of global cancer cases, with HPV-associated oropharyngeal cancers now surpassing cervical cancers in the United States, representing an epidemic. Notably, HPV16 is the leading cause of oropharyngeal cancers. Following infection, HPV maintains its genome in basal epithelial cells, exploiting cellular processes for replication via oncogene expression, while the balance between transformation and productive infection remains a crucial inquiry. To study the HPV16 lifecycle and address the role of HPV16 in oropharyngeal cancer, we generate primary tonsil-derived epithelial cells that maintain the HPV16 genome. For unclear reasons, it is technically challenging to generate these cell lines, creating a bottleneck for reproducible research in this area. To address this, we will develop molecular tools using primary epithelial cells from tonsillectomies, a physiologically relevant model for HPV16-driven oropharyngeal cancer. Aim 1 will develop a complementation assay to enhance the recovery of cells with episomal viral DNA. Furthermore, different HPV16 variants may exhibit varying oncogenic properties and replicative capacities in cell culture. In Aim 2, we will quantify lifecycle stages and tumorigenicity across HPV16 variant genomes using primary tonsillar epithelial cells. Despite technical hurdles, studying HPV16 in the lab is vital for understanding the viral role in the development of oropharyngeal cancer. Developing novel methods to select infected cells and discern variant-specific phenotypes promises to advance HPV research, aligning with the NIH mission and fitting the scope of an R03 proposal. Future research will use these tools to ask biological questions, compare and contrast viral types (e.g., HPV16 vs HPV18), study HPV16 variants further, and aid in understanding the role of HPV16 in oropharyngeal cancers.