Comparative Analysis of Protocols to Induce Human CD4+Foxp3+ Regulatory T Cells by Combinations of IL-2, TGF-beta, Retinoic Acid, Rapamycin and Butyrate

• Published in: PloS one Vol. 11; no. 2; p. e0148474
• Main Authors: Schmidt, Angelika, Eriksson, Matilda, Shang, Ming-Mei, Weyd, Heiko, Tegnér, Jesper
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.02.2016; Public Library of Science (PLoS)
• Subjects: Acids; Adoptive transfer; Animal models; Animals; Antigens; Autoimmune diseases; Biology and life sciences; Bone morphogenetic proteins; Butyrates - pharmacology; Cancer; CD4 antigen; Cells; Clinical trials; Comparative analysis; CTLA-4 protein; Cytokines; Dendritic cells; Deoxyribonucleic acid; Disease; DNA; DNA methylation; Dosage and administration; Drug therapy; Female; Forkhead Transcription Factors - metabolism; Foxp3 protein; Graft vs Host Disease - immunology; Graft vs Host Disease - pathology; Health aspects; Hospitals; Humans; Immune system; Immunological tolerance; Immunoregulation; Inflammatory diseases; Interferon; Interferon-gamma - metabolism; Interleukin 10; Interleukin 17; Interleukin 2; Interleukin-10 - metabolism; Interleukin-17 - metabolism; Interleukin-2 - pharmacology; Lymphocyte Activation - drug effects; Lymphocytes; Lymphocytes T; Medicine; Medicine and health sciences; Methylation; Mice, Inbred NOD; Rapamycin; Research and Analysis Methods; Retinoic acid; Rodents; Sirolimus - pharmacology; T cell receptors; T-Lymphocytes, Regulatory - drug effects; T-Lymphocytes, Regulatory - immunology; Transforming Growth Factor beta - pharmacology; Transforming growth factor-b; Transforming growth factors; Tretinoin - pharmacology; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0148474

Regulatory T cells (Tregs) suppress other immune cells and are critical mediators of peripheral tolerance. Therapeutic manipulation of Tregs is subject to numerous clinical investigations including trials for adoptive Treg transfer. Since the number of naturally occurring Tregs (nTregs) is minute, it is highly desirable to develop a complementary approach of inducing Tregs (iTregs) from naïve T cells. Mouse studies exemplify the importance of peripherally induced Tregs as well as the applicability of iTreg transfer in different disease models. Yet, procedures to generate iTregs are currently controversial, particularly for human cells. Here we therefore comprehensively compare different established and define novel protocols of human iTreg generation using TGF-β in combination with other compounds. We found that human iTregs expressed several Treg signature molecules, such as Foxp3, CTLA-4 and EOS, while exhibiting low expression of the cytokines Interferon-γ, IL-10 and IL-17. Importantly, we identified a novel combination of TGF-β, retinoic acid and rapamycin as a robust protocol to induce human iTregs with superior suppressive activity in vitro compared to currently established induction protocols. However, iTregs generated by these protocols did not stably retain Foxp3 expression and did not suppress in vivo in a humanized graft-versus-host-disease mouse model, highlighting the need for further research to attain stable, suppressive iTregs. These results advance our understanding of the conditions enabling human iTreg generation and may have important implications for the development of adoptive transfer strategies targeting autoimmune and inflammatory diseases.