In Vitro α-Galactosylceramide Stimulation Expands CD4+CD25+Foxp3− Regulatory T Cell Precursors in Murine Thymocytes
1Urology, Tokyo Women's Medical University, Tokyo, Japan
2Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
3Urology, Jyoban Hospital of Tokiwa Foundation, Fukushima, Japan
4Laboratory for Immunotherapy, Center for Integrative Medical Sciences (IMS) RIKEN, Yokohama, Japan.
Meeting: 2018 American Transplant Congress
Abstract number: A434
Session Information
Session Name: Poster Session A: Tolerance / Immune Deviation
Session Type: Poster Session
Date: Saturday, June 2, 2018
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Hall 4EF
Background: We previously established mixed chimerism after invariant natural killer T-cell stimulation by administration of liposomal α-galactosylceramide (lipo-αGC) and costimulatory blockade, leading to regulatory T cell (Treg) expansion in mice. In this regimen, the thymus was considered important because Tregs failed to expand in thymectomized mice, resulting in a chimerism brake. In the thymus, Tregs are known to develop through a two-step process: first, post-positive-selection thymocytes differentiate into CD4+CD25+Foxp3− Treg precursors (preTregs) in a T cell receptor (TCR)-dependent manner, and second, IL-2 stimulation causes these preTregs to develop into Tregs. Herein, we investigated the effect of lipo-αGC on this process by using a primary thymocyte culture system.
Methods: Thymocytes from BALB/c mice were incubated with lipo-αGC for 3 days. Thereafter, the cell population was analyzed and levels of various cytokines (interleukin (IL)-2, IL-4, IL-10, and interferon-γ) were measured in the culture supernatant by flow cytometry using the Cytometric Beads Array. To evaluate their ability to differentiate into Foxp3+ Tregs, CD4+CD25+Foxp3− cells sorted from lipo-αGC-stimulated thymocytes of Foxp3-GFP BALB/c mice were stimulated with IL-2 for 24 hours, and Foxp3-GFP expression was then analyzed by flow cytometry.
Results: CD4+CD25+Foxp3+ Treg and CD4+CD25+Foxp3– cell numbers increased in lipo-αGC-stimulated thymocytes compared to that in unstimulated thymocytes. Cytokine production levels between the two groups were comparable. Thus, lipo-αGC stimulation may affect the first step[mdash]TCR-dependent preTreg expansion[mdash]in the aforementioned two-step process. Foxp3 expression in CD4+CD25+Foxp3– cells was induced in an IL-2-dependent manner. Taken together, these results indicate that the CD4+CD25+Foxp3– cell population contained preTregs.
Conclusions: In vitro lipo-αGC stimulation can cause preTreg expansion followed by Treg development, suggesting that invariant natural killer T cells may be involved in regulation of thymic Treg differentiation and development.
CITATION INFORMATION: Katsumata H., Ikemiyagi M., Kanzawa T., Fukuda H., Ishii R., Saiga K., Okumi M., Ishii Y., Tanabe K. In Vitro α-Galactosylceramide Stimulation Expands CD4+CD25+Foxp3− Regulatory T Cell Precursors in Murine Thymocytes Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:
Katsumata H, Ikemiyagi M, Kanzawa T, Fukuda H, Ishii R, Saiga K, Okumi M, Ishii Y, Tanabe K. In Vitro α-Galactosylceramide Stimulation Expands CD4+CD25+Foxp3− Regulatory T Cell Precursors in Murine Thymocytes [abstract]. https://atcmeetingabstracts.com/abstract/in-vitro-galactosylceramide-stimulation-expands-cd4cd25foxp3-regulatory-t-cell-precursors-in-murine-thymocytes/. Accessed December 2, 2024.« Back to 2018 American Transplant Congress