Phage Display-Based Discovery of HPV Capsomere-Specific Antibodies for HPV Process Characterization

Human papillomaviruses (HPV) are a group of viruses that primarily infect squamous epithelial cells, often leading to proliferative lesions and various cancers. It is estimated that over 80% of sexually active adults will acquire HPV by the age of 45. The HPV capsid is composed of two major capsid proteins, L1 and L2, which co-assemble to form the viral structure. Notably, the L1 protein can self-assemble into virus-like particles (VLPs) that exhibit significant structural and immunological similarities to the native virus capsid. This self-assembly involves formation of critical repeating pentamer subunits known as capsomeres. In this study, we generated and characterized monoclonal antibodies (mAbs) specific to capsomeres to understand and improve HPV vaccine manufacturing process. We prepared high-purity Type16 capsomeres and utilized phage display technology to developed high affinity mAbs for T16 capsomeres. We used immunoassays and biophysical analyses to demonstrate that these antibodies can selectively bind to T16 capsomeres but not T16 VLPs. Furthermore, we established an enzyme-linked immunosorbent assay (ELISA) employing one of these antibodies to quantify capsomeres in cell lysates. Our findings demonstrate that these antibodies are valuable tools for probing process intermediates at previously inaccessible stages to enable greater process understanding and more efficient process development.