Engineered antigen-specific regulatory T cells
department or school: Medicine, Faculty of
department or school: Medicine, Department of
data provider: DSpace
degree campus: UBCV
creator: Dawson, Nicholas Aaron James
issued: 2019-10-07T20:55:42Z
issued: 2019
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Achieving transplant tolerance with regulatory T cell (Treg) adoptive immunotherapy is currently under investigation as a therapy to reduce graft rejection, improve long-term outcomes, and patient quality of life. Initial approaches involve expansion of naturally-occurring Tregs, either polyclonal or antigen-specific, however both of these approaches have several technical limitations that restrict implementation at a large-scale. To circumvent these limitations, this work describes an alternate approach to generate antigen-specific Tregs by expressing a chimeric antigen receptor specific for HLA-A*02:01 (A2-CAR), which activates Tregs in the presence of HLA-A*02:01, a tissue antigen allele that is commonly mismatched between transplant donor and recipient. In the first CAR Treg studies, the antigen-binding region (scFv) of the A2-CAR was derived from the mouse BB7.2 hybridoma, which could cause immunogenic responses and limit its efficacy in humans. Additionally, most CAR Treg studies to date employ CD28 and CD3 signaling domains to activate the cell, but alternative co-receptor signaling moieties have not been adequately tested. Two major improvements to CAR Treg technology are explored: (1) the scFv is humanized to reduce the immunogenicity of the CAR construct itself, rendering it less likely to cause immune responses in humans and (2) a collection of a variety of co-receptor intracellular domains are tested in place of CD28 to determine whether alternative signals can bestow Tregs with more beneficial functional properties. In the final chapter, a method for staining FOXP3, the Treg master transcription factor, using mass cytometry is described to enable thorough tracking of FOXP3⁺ Tregs and the rest of the immune compartment in patient samples from various tissues. Collectively, this body of work furthers our understanding of Treg immunotherapies and provides further support for their use in transplant settings.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/71844
note: ENGINEERED ANTIGEN-SPECIFIC REGULATORY T CELLS by Nicholas Aaron James Dawson B.Sc., The University of British Columbia, 2013 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Experimental Medicine) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) October 2019 © Nicholas Aaron James Dawson, 2019 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: ENGINEERED ANTIGEN-SPECIFIC REGULATORY T CELLS submitted by Nicholas Aaron James Dawson in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Experimental Medicine Examining Committee: Megan K Levings Supervisor Soren Gantt Supervisory Committee Member Laura Sly University Examiner Andrew Weng University Examiner Additional Supervisory Committee Members: Kenneth Harder Supervisory Committee Member Scott Tebbutt Supervisory Committee Member Raewyn Broady Supervisory Committee Member iii Abstract Achieving transplant tolerance with regulatory T cell (Treg) adoptive immunotherapy is currently under investigation as a therapy to reduce graft rejection, improve long-term outcomes, and patient quality of life. Initial approaches involve expansion of naturally-occurring Tregs, either polyclonal or antigen-specific, however both of these approaches have several technical limitations that restrict implementation at a large-scale. To circumvent these limitations, this work describes an alternate approach to generate antigen-specific Tregs by expressing a chimeric antigen receptor specific for HLA-A*02:01 (A2-CAR), which activates Tregs in the presence of HLA-A*02:01, a tissue antigen allele that is commonly mismatched between transplant donor and recipient. In the first CAR Treg studies, the antigen-binding region (scFv) of the A2-CAR was derived from the mouse BB7.2 hybridoma, which could …
has type: Thesis/Dissertation
date issued: 2019-11
is shown at: 10.14288/1.0383301
language: eng
degree discipline: Experimental Medicine
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/71844