Abstract 2211: Characterization of monoclonal antibodies specific for HPV-positive head and neck cancer

HPV-driven head and neck squamous cell carcinoma (HNSCC) are among the fastest growing cancers. Although, HPV-HNSCC patients have an overall favorable prognosis, a significant number of patients relapse post-treatment, and currently there is no specific therapeutic approach targeting the unique biology of HPV-driven HNSCC. Our ongoing efforts to target HPV-HNSCC focus on the identification of cell surface antigens that are upregulated by HPV infection. We have developed an "antigen-agnostic" approach for generating HPV-HNSCC-targeting monoclonal antibodies for cancer diagnosis and treatment that does not rely on prior identification of target antigens. We used HPV-HNSCC membrane fractions to immunize recipient mice and generated HPV-specific hybridomas. We then screened five thousand hybridoma colonies by flow cytometry to test the specificity of binding to HPV-positive cancer cell lines (2HNSCC and 2 Cervical Cancer) and HPV-negative cancer cell lines (4 HNSCC and 1 CC). After primary screening, we narrowed down to forty-four clones; among these hybridoma clones, 6D8 and 6B3 bound preferentially to HPV-positive cancer cell lines. The binding targets of 6D8 and 6B3 were identified by immunoprecipitation and mass spectrometry; their targets are integrin alpha6 (ITGA6) and tissue factor (F3) respectively. Future work will validate the biological function of these mAbs in in vitro and in vivo models, and continue identifying more binding target of mAbs. We propose mAbs specifically targeting membrane-expressed antigens on HPV-related cancer cells as a potential approach for early diagnosis and targeted therapy. Citation Format: Hsuan-Chen Liu, Falguni Parikh, Thomas Kraus, Thomas Moran, Andrew Sikora. Characterization of monoclonal antibodies specific for HPV-positive head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2211. doi:10.1158/1538-7445.AM2017-2211