Epitope Mapping of Small Non-Enveloped Icosahedral Viruses
Open Access
- Author:
- Charnesky, Andrew
- Graduate Program:
- Molecular, Cellular, and Integrative Biosciences
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- October 06, 2023
- Committee Members:
- Troy Sutton, Major Field Member
Jean-Paul Armache, Major Field Member
Melissa Rolls, Program Head/Chair
Neil Christensen, Outside Unit Member
Moriah Szpara, Outside Field Member
Anthony Schmitt, Co-Chair & Dissertation Advisor
Susan Hafenstein, Co-Chair & Dissertation Advisor - Keywords:
- Cryo EM
Poliovirus
Canine Parvovirus
Antibody
Fab
Epitope
Subparticle - Abstract:
- The connecting thread through all chapters of this dissertation is the structural analysis of antibody fragment complexed with non-enveloped viruses and mapping of the resulting epitopes. This is achieved through a mix of cryo EM and biochemistry techniques. Structure based viral epitope mapping is useful in several applications. From a therapeutics perspective, it can establish a neutralizing mechanism, characterize new neutralizing epitopes, give context for evaluation of escape potential, and allow more intelligent combination therapy or drug cocktail design. It also can function as a tool to answer some questions on viral biology, where stabilization or ligand mimicry can be done by antibodies. The in vitro customizability and functionalization of antibodies further expands the repertoire of applications in cryo EM as well as other disciplines. The non-enveloped viruses focused on in this dissertation are poliovirus and canine parvovirus. Poliovirus, the causative agent of poliomyelitis, has been brought under control since peak transmission from the mid 1900s due to vaccination, but those vaccines are still unable to complete the elimination of the virus worldwide. Chapters 2 and 4 help to characterize human monoclonal antibodies to all three serotypes of poliovirus, to better understand them, their epitopes and mechanisms of neutralization (receptor blocking, stabilization, or other), and lay more groundwork for potential subsequent development into therapeutics. Canine parvovirus jumped from felines to canines and quickly caused an epidemic in the late 1970s. Chapter 3 explores a canine polyclonal response to the virus. This mixed antibody response to vaccination can only be characterized structurally in cryo EM by subparticle methods and builds upon the early work in the field of polyclonal response mapping to viruses. The subparticle approach is central to Chapter 3, but also supports epitope mapping in Chapters 2 and 4. Through these methods Cryo EM will remain a central technique for analyzing antibody-viral complexes, helping answer questions both therapeutic and biological.