Abstract A132: Pathological analysis of a newly established immunocompetent mice with full Hpv16 genome integration

Abstract Human papillomaviruses (HPV) are associated with both benign and malignant epithelial lesions. High-risk HPV subtype HPV 16 is the causative agent of cervical and the majority of oropharyngeal squamous cell carcinomas. Despite the continuous increase in the disease burden, mechanisms and pathways of HPV16-induced cancer growth are not fully understood, thus leading to suboptimal treatment. In last decades, several transgenic mouse models were developed, helped tremendously to study HPV-induced carcinogenesis. However, all existent HPV transgenic mice were targeted early genes expression driven by an artificial promoter and did not encompass the functionality of the whole HPV genome, including the upstream regulatory region (URR) that contains HPV promoters, regulatory elements, and a replication origin, limited our ability to investigate HPV-associated malignant transformation and the role of host factors in this process. Therefore, we generated HPV16 transgenic mouse by using CRISPR/Cas9-mediated genome editing to insert the full-length HPV16 genome into the Rosa26 locus. Two founder mice, with single HPV copy and with tandem HPV integration, were used to establish mouse colonies. Interestingly, regardless of HPV copy number, ~50% of the HPV knock-in mice exhibited early death during the first 2 weeks after birth, while survived pups were significantly smaller than the same age wild-type mice, and had severe hair loss. Intriguingly, the growth retardant and hair loss phenotype in the HPV16 knock-in mice disappeared in ~4 weeks, most likely indicating that viral genes compromise specific stages of mouse development. We evaluated the expression of HPV genes during development, in different mouse organs, and in established fibroblasts and epithelial cell cultures. Our newly established HPV16 knock-in mouse model provides viral gene expression from natural viral promoters offering an essential basis to explore the role of cellular factors in HPV-driven pathologies. Citation Format: Xue Li, Aditi Kothari, Hina Rehmani, Wendell Yarbrough, Natalia Isaeva. Pathological analysis of a newly established immunocompetent mice with full Hpv16 genome integration [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A132.