Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Addition of Retinoic Acid and TGF-beta Accelerate the Maturation Naive CD8 Cells into CD8CD25FOXP3 Regulatory Cells.

Gray1,  J. Dixon, Pan2,  Stephanie Q., Horwitz1,  David A.

University of Southern California, Los Angeles, CA
University of Southern California

Purpose:

Regulatory T cells (Tregs) maintain immunologic homeostasis and prevent autoimmunity. Defects in the numbers and function of CD4+ Tregs in SLE and other immune-mediated rheumatic diseases are well described. Besides their well described cytotoxic activities, several populations of CD8+ regulatory cells (Treg) have been described that occur naturally or can be induced ex-vivo and some of these subsets express Foxp3. The conditions required to induce mature functionally competent Foxp3+ Tregs are not well understood. We have reported that human naïve CD4+ cells polyclonally stimulated with IL-2, TGF-b and all-trans retinoic acid (atRA) rapidly become CD25+CD127- Foxp3+ cells with marked suppressive activity both in vitro and in vivo. Here the objective was to learn whether CD8+ cells could become Treg cells with a similar phenotype and function.

Methods:

CD8+ CD28+ CD45RA+ CD127+ CD62Lhi CD25- cells from healthy subjects were stimulated with suboptimal numbers of anti-CD3/CD28 coated beads + IL-2 ± TGF-b or atRA for 5 to 7 days. Since all anti-CD3 activated CD8+ cells inhibit T cell proliferation in vitro, we investigated their ability to protect into immunodeficient NOD SCID IL-2R common gamma chain-/- (NOG) mice from a human anti-mouse GVHD.

Results:

Activation of naïve CD8+ cells with TGF-b doubled Foxp3 expression and the cells became CD103+, but the cells retained a naïve phenotype and remained CD127+. With the addition of atRA to TGF-b, Foxp3 expression was consistently >50%. They remained predominantly CD62Lhi, but became CD45RO+ and CD127-, consistent with a regulatory phenotype. The transfer of 20×106 human CD25- PBMC to NOG mice results in the rapid demise of these animals. The addition of atRA/TGF-b CD8reg in a ratio of 1: reg to 4 PBMC doubled the survival of the mice. Studies with other epigenetic agents and comparing the effects of CD4 and CD8regs separately and together will be reported.

Conclusions:

Although to date, attention has been focused on CD4reg, studies in both mouse and human SLE have documented an important, if not essential, role of CD8regs. The ability to rapidly generate both CD4+ and CD8+ Foxp3+ Tregs using convention cell separation techniques represents a novel, practical strategy to treat patients with SLE and other chronic inflammatory immune-mediated rheumatic diseases.

To cite this abstract, please use the following information:
Gray, J. Dixon, Pan, Stephanie Q., Horwitz, David A.; Addition of Retinoic Acid and TGF-beta Accelerate the Maturation Naive CD8 Cells into CD8CD25FOXP3 Regulatory Cells. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1242
DOI: 10.1002/art.29008

Abstract Supplement

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