MS is an autoimmune neurodegenerative disease of the central nervous system (CNS) in which the etiology is not well understood. Although, auto-aggressive CD4+ T cells play a central role, the breakdown of immune tolerance mechanisms that permits activation of naive myelin-specific T cells is considered an initial step in the pathogenesis of MS. A number of pivotal studies in rodent models have substantiated that Ag- specific Tregs have a significant role in modulating autoimmune CNS disease and can be highly effective at treating MS. Consequentially, there has been a major focus in developing protocols that stimulate Treg numbers and their function. Unfortunately, successful therapeutic use of Tregs has been limited by the lack of safe and effective Ag-specific protocols for isolation and expansion that are suitable for translation. The AAV gene transfer platform has clearly demonstrated that hepatocyte-restricted transgene expression from an optimized AAV vector can reliably induce immune tolerance to various therapeutic proteins. Importantly, tolerance is dependent on achieving and maintaining adequate hepatocyte-restricted transgene expression that induces Ag-specific CD4+CD25+FoxP3+ Tregs. Recently, we have successfully developed a clinically relevant Adeno-associated Virus (AAV) immunotherapy that is not only capable of preventing the development of EAE, but can also reverse the neurological symptoms of preexisting disease. This vector-based immunotherapy uses the full-length protein coding sequence of a myelin-derived protein, which abrogates the need to identify HLA/MHC specific epitopes, making this unique approach universally applicable. Mechanistically, this process is based on the induction of immunological tolerance mediated by antigen specific Tregs. We hypothesize that a persistent immunological tolerance, independent of MHC restrictions can be established against three immunogenic myelin proteins, simultaneously. That such tolerance is mediated by the induction and expansion of Ag-specific Tregs that can prevent development of and reverse existing disease in the EAE model of MS.
Aim 1 : Develop, optimize and compare in vivo performance of AAV-PLP and -MBP vectors, and assess functional suppression of Ag-specific Tregs Aim 2: Demonstrate that AAV immunotherapy vectors can prevent or ameliorate disease in genetically diverse strains of mice.
Aim3 : Determine the minimum effective vector (MEV) dose for abrogation of disease without an adverse immune response or hepatotoxicity.
Aim 4 : Establish a multi-vector / multi-gene immunotherapy platform.

Public Health Relevance

MS is a neuro-inflammatory autoimmune disease in which T cell driven inflammation leads to demyelination and damage of axons. The overall goal for is proposal is to develop a clinically relevant Adeno- associated virus (AAV) immunotherapy that will restore tolerance in an autoimmune setting such as Multiple Sclerosis (MS). We will show that our protocol will induce and expand antigen (Ag)-specific regulatory T-cells (Tregs) in vivo and independent of MHC or epitope restrictions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI128074-02
Application #
9402586
Study Section
Gene and Drug Delivery Systems Study Section (GDD)
Program Officer
Esch, Thomas R
Project Start
2017-01-01
Project End
2021-12-31
Budget Start
2018-01-01
Budget End
2018-12-31
Support Year
2
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Florida
Department
Pediatrics
Type
Schools of Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611