[F31] Characterizing cleavage of L2 by γ-secretase during HPV infection and antibody neutralization

Description

PROJECT SUMMARY/ABSTRACT HPV is the causative agent for cervical cancer, although it is also associated with other anogenital and oral cancers, as well as skin cancers in immune-compromised individuals. HPV encodes two capsid proteins, L1 and L2. L1 makes up most of the viral capsid, and it elicits an immunodominant and highly HPV-type specific protective antibody response. L2 is highly conserved across HPV types but it is less immunogenic than L1. However, virus-like display of a conserved L2 protective epitope (residues 17-36) produces a robust neutralizing and protective antibody response. Despite the strides in the prevention of cervical cancer by licensed L1-based vaccines (e.g., Gardisil-9), numerous high risk HPV types are not covered, including those associated with skin cancer. There remains a major medical need for new vaccine strategies that can offer broad protection against HPV types. Therefore, our research focuses on exploiting L2 17-36 displayed on a virus-like particle as a next- generation broadly protective HPV vaccines because of its sequence conservation across HPV types. Here, I propose to dissect how L2 functions in its interaction with γ-secretase to facilitate viral passage toward the nucleus, and how L2-specific antibodies prevent infection post-entry to inform vaccine design. Our scientific premise that γ-secretase cleavage of L2 is essential for HPV infection is based on the following findings: 1) genetic and inhibitor studies show that regulated intramembrane protease by γ-secretase’s catalytic subunit presenilin-1 (PS1) is required for infection by HPV, 2) γ-secretase can cleave L2 and cleaved L2 enters the nucleus. Ultimately, improved knowledge of the processes of infection and how antibodies neutralize HPV is important to design better vaccines. Based on our preliminary results we hypothesize that: 1) Cleavage by -secretase requires recognition of key conserved residues in and around L2’s cryptic transmembrane domain that are necessary for infection and 2) L2-specific antibodies prevent its cleavage by -secretase to neutralize viral infection. To test these hypotheses, we propose the following specific aims: 1) To determine the residues of L2 required for membrane insertion and -secretase binding and cleavage, and 2) To determine the protective effects of L2-specific antibodies. Impact: This study will provide important basic knowledge of -secretase function and papillomavirus biology and inform HPV vaccine development, while providing PI Jade Alvarez excellent training. The Johns Hopkins University School of Medicine provides a rigorous and supportive environment for the PI, Jade Alvarez, to complete these research goals and achieve the highest quality training under a committed and experienced mentor, Dr. Roden. Ms. Alvarez will learn diverse techniques, publish first-author manuscripts, and present her findings at scientific meetings. This training will well prepare Ms. Alvarez for a career in academia. Istituzione: JOHNS HOPKINS UNIVERSITY PI: Jade Alvarez Progetto: 1F31AI197617-01

Sectors

Source

Source: reporter.nih.gov