DOI
https://doi.org/10.25772/9SFF-J137
Defense Date
2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Microbiology & Immunology
First Advisor
Richard Marconi
Second Advisor
Jason Carlyon
Third Advisor
Rebecca Martin
Fourth Advisor
Chunhao Li
Fifth Advisor
Brian Wattenberg
Abstract
Lyme disease (LD) is a tick-transmitted infection caused by Borreliella burgdorferi in North America and several closely related species in Europe and Asia (collectively referred to as the LD spirochetes).Preventative strategies for LD in humans are poorly developed and largely inadequate. While preventive vaccines for LD are widely used in veterinary medicine, vaccines are not available for use in humans. This study aimed to develop a human vaccine that can elicit antibody responses that kill spirochetes in tick and mammalian environments. The approach applied in this study centered on the development of chimeric epitope proteins, referred to as chimeritopes. Chimeritopes are recombinant proteins consisting of a series of epitopes derived from one or more proteins or protein variants. An example of a successful chimeritope-based vaccine is VANGUARD®crLyme, developed by this lab and produced by Zoetis. Utilizing a similar chimeric-based approach, two novel chimeric proteins were designed (BAF and Chv2M) for potential use as a human LD vaccine. BAF consists of a full-length OspB with two immunogenic linear epitopes of OspA (OspA221-240) inserted downstream of OspB244-260, a region that shares homology with OspA. Additionally, BAF includes the N-terminal domain of FtlA, an antigen expressed during tick and mammalian infection. Chv2M is an optimized variant of the OspC chimeritope Chv2. Chv2M comprises 20 highly immunoreactive epitopes from 10 different OspC types. Immunoblot and ELISA analyses using sera from vaccinated animals demonstrated that Chv2M elicits IgG antibodies that recognize diverse OspC types. Bactericidal assays using antisera generated to BAF and Chv2M demonstrated potent bactericidal activity against B. burgdorferi,thus establishing an important in vitro correlate of protection. Vaccination of mice with BAF and Chv2M protected against B. burgdorferi infection. The immunogenicity and protective efficacy of the vaccine formulation is currently being tested in the non-human primate model for Lyme disease.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
12-5-2023