Development of Stem Cell-derived Antigen-specific Regulatory T Cells Against Autoimmunity

Summary

We present here a method to develop functional antigen (Ag)-specific regulatory T cells (Tregs) from induced pluripotent stem cells (iPSCs) for immunotherapy of autoimmune arthritis in a murine model.

Abstract

Autoimmune diseases arise due to the loss of immunological self-tolerance. Regulatory T cells (Tregs) are important mediators of immunologic self-tolerance. Tregs represent about 5 - 10% of the mature CD4⁺ T cell subpopulation in mice and humans, with about 1 - 2% of those Tregs circulating in the peripheral blood. Induced pluripotent stem cells (iPSCs) can be differentiated into functional Tregs, which have a potential to be used for cell-based therapies of autoimmune diseases. Here, we present a method to develop antigen (Ag)-specific Tregs from iPSCs (i.e., iPSC-Tregs). The method is based on incorporating the transcription factor FoxP3 and an Ag-specific T cell receptor (TCR) into iPSCs and then differentiating on OP9 stromal cells expressing Notch ligands delta-like (DL) 1 and DL4. Following in vitro differentiation, the iPSC-Tregs express CD4, CD8, CD3, CD25, FoxP3, and Ag-specific TCR and are able to respond to Ag stimulation. This method has been successfully applied to cell-based therapy of autoimmune arthritis in a murine model. Adoptive transfer of these Ag-specific iPSC-Tregs into Ag-induced arthritis (AIA)-bearing mice has the ability to reduce joint inflammation and swelling and to prevent bone loss.

Introduction

Autoimmune arthritis is a systemic disease characterized by hyperplasia of synovial tissue and progressive destruction of articular cartilage, bone, and ligaments¹. The defective generation or function of Tregs in autoimmune arthritis contributes to chronic inflammation and tissue injury because Tregs play a crucial role in preventing the development of auto-reactive immune cells.

Manipulation of Tregs is an ideal strategy for the development of therapies to suppress inflammation in an Ag-dependent manner. For Treg-based immunotherapy, the specificity of the transferred Tregs is important for the treatment of ongoing autoimmunit....

Protocol

All animal experiments are approved by the Pennsylvania State University College of Medicine Animal Care Committee (IACUC protocol #45470) and are conducted in compliance with the guidelines of the Association for the Assessment and Accreditation of Laboratory Animal Care.

1. Stem Cell Culture

1. Incubate a 10 cm dish with 10 ml of 0.1% gelatin for at least 30 min at 37 °C (incubator) in order to coat the plate.
2. Remove gelatin from the dish and plate 3 x 10⁶ irradiated SNL76/7 cells and incubate for one day at 37 °C (incubator) using 10% DMEM media (10% FBS and 1% penicillin streptomycin).
3. R....

Results

As shown here, on day 28, Ag-specific Tregs substantially expressed CD3 and Ag-specific TCR, two T cell markers. The CD3⁺TCRVβ5⁺ population expressed CD4. Most of the CD3⁺TCRVβ5⁺CD4⁺ cells also expressed CD25, CD127, and CTLA-4, which are typically expressed at elevated levels in naturally occurring T_regs (nTregs) and in T cells expressing FoxP3 ectopically. FoxP3 expression in iPSC-derived cells persisted even after long-t.......

Discussion

In this protocol, a critical step is the in vitro differentiation of TCR/FoxP3 gene-transduced iPSCs. In vitro Notch signaling induces development towards the T cell lineage. To differentiate iPSCs into CD4⁺FoxP3⁺ Tregs, we used the OP9-DL1/DL4/I-A^b cells, which highly express MHC II (I-A^b) molecules. Most of the iPSCs differentiate into CD4⁺ cells. However, after the surface TCR expression, many differentiated pre-T cells lose the ability to differ.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
C57BL/6j mice	Jackson Laboratory	664
B6.129S7 Rag1tm1Mom/J	Jackson Laboratory	2216
Anti-CD3 (2C11) antibody	BD Pharmingen	553058
Anti-CD28 (37.51) antibody	BD Pharmingen	553295
Anti-CD4 (GK1.5) antibody	Biolegend	100417
Anti-CD8 (53–6.7) antibody	Biolegend	100714
Anti-CD25 (3C7) antibody	Biolegend	101912
Anti-TCR-β (H57597) antibody	Biolegend	109220
Anti-IL10	Biolegend	505010
Anti-TGFβ	Biolegend	141402
DMEM	Invitrogen	ABCD1234
α-MEM	Invitrogen	A10490-01
FBS	Hyclone	SH3007.01
Brefeldin A	Sigma	B7651
Polybrene	Sigma	107689
Genejammer	Integrated science	204130
ACK Lysis buffer	Lonza	10-548E
mFlt-3L	peprotech	250-31L
mIL-7	peprotech	217-17
Gelatin	Sigma	G9391
Paraformaldehyde	Sigma	P6148-500G	Caution: Allergenic, Carcenogenic, Toxic
Permeabilization buffer	Biolegend	421002
mBSA	Sigma	A7906
Ova albumin	Avantor	0440-01
CFA	Difco	2017014
Tailveiner restrainer	Braintree scientific	RTV 150-STD