Ex Vivo Induction of Type 2 T Helper Cell Tolerance by Human Regulatory Dendritic Cells in Atopic Asthma
Date
2025-03-25
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0005-2792-2210
Type
Thesis
Degree Level
Doctoral
Abstract
Over half of asthmatic disease falls within the atopic asthma subtype, in which allergen-specific type II T helper (Th2) cells are pivotal players. Dendritic cells regulate these adaptive immune responses, in large part through their communication with such T cells. Under some induced and naturally occurring conditions, dendritic cells can develop into anti-inflammatory cells called ‘regulatory dendritic cells’ (DCreg), which can induce antigen-specific T cell tolerance and regulatory T cell (Treg) differentiation. Herein we have developed a novel cyclosporine A-differentiated DCreg (DC-CsA) and examined its tolerogenic potential ex vivo in the context of human atopic asthma. Our DC-CsA were generated from peripheral monocytes of atopic asthmatic donors and characterized in terms of their cell surface markers and secreted mediators, as well as their transcriptomic profile, and abilities to suppress T cell responses in vitro. We found that our DC-CsA secreted more than 500-fold more IL-10 than our comparative stimulatory DC population (DCstim), with high IL-10/IL-12 and IL-10/TNF expression ratios. Cell surface marker analysis of DC-CsA by fluorescence-activated cell sorting and/or cytometry by time-of-flight revealed reduced expression of CD83, CD86, and Fas/FasL relative to DCstim. Transcriptome analysis via ribonucleic acid sequencing identified transcripts for more than 13,000 differentially regulated genes between DC-CsA and DCstim, including upregulation of IL-10, IL-6, ALDH1A2, C1Q, DC-SIGN, LAIR1, and the ATP ectonuclease CD39, various T cell chemoattractants (i.e., CCL1, CCL2, CCL3, CCL8, CCL18, CCL20, CXCL1 and CXCL2), chemokine receptors (i.e., CCR1, CCR5 and CXCR1), and tolerance-associated markers ANXA1, F13A1, FKBP5, MRC1 and STAB1.
Co-culture experiments with allergen-presenting DC-CsA and allergen-stimulated autologous Th2 cells demonstrated that DC-CsA suppress activation of cognate Th2 cell responses. Moreover, activated T cell-DC-CsA co-cultures induced CD4+CD40L+ T cells to become functional Treg, which are similarly able to suppress Th2 cell proliferation and cytokine responses. When such DC-CsA-induced Treg were isolated and introduced into cultures of CFSE-labeled Th2 cells and allergen-presenting DCstim, we observed a 4.8-fold increase in the proportion of CFSE+ Treg. That is, both our DC-CsA and our DC-CsA-induced Treg were each able to convert Th2 cells into Treg, a critical feature to the regulatory feedback loop known as ‘infectious tolerance’.
Description
Keywords
Regulatory Dendritic Cells, tolerance, allergic tolerance, regulatory T cells, dendritic cell therapy, cellular therapy
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Medicine
Program
Health Sciences