Inducible regulatory T cells (iTregs) from recent-onset type 1 diabetes subjects show increased in vitro suppression and higher ITCH levels compared with controls
CD4+CD25+high regulatory T cells (Tregs) play a pivotal role in the control of the immune response. A growing body of evidence suggests the reduced function of these cells in autoimmune diseases, including type 1 diabetes (T1D). Restoration of their function can potentially delay further disease development. In the present study, we have converted conventional effector T cells into induced Tregs (iTregs) in recent-onset (RO) T1D (n=9) and compared them with the same cells generated in controls (n=12) and in long-standing (LS) T1D subjects (n=9). The functional potential of in-vitro-generated Tregs was measured by using an in vitro proliferation assay. We noted that the suppressive potential of iTregs exceeded that of natural regulatory T cells (nTregs) only in the RO T1D subjects. We showed that iTregs from RO T1D subjects had increased expression of Foxp3, E3 ubiquitin ligase (ITCH) and TGF-β-inducible early gene 1 (TIEG1) compared with control and LS T1D subjects. We also expanded natural, thymically derived Tregs (nTregs) and compared the functional ability of these cells between subject groups. Expanded cells from all three subject groups were suppressive. RO T1D subjects were the only group in which both iTregs and expanded Tregs were functional, suggesting that the inflammatory milieu impacts in vitro Treg generation. Future longitudinal studies should delineate the actual contribution of the stage of disease to the quality of in-vitro-generated Tregs.
KeywordsType 1 diabetes Tregs Induced Tregs Expansion E3 ubiquitin ligase Apoptosis Human
The authors thank Hope Alberts, Jeffrey Woodliff, and Corbett Reynbold for FACS services, Marilyn Koppen and Joanna Kramer for patient recruitment, and Karen Zeqiri for administrative support. They also express their sincere gratitude to all study participants for their generosity and enthusiastic support of this work.
- ABI (1997) Relative quantitation of gene expression; ABI prism 7700 sequence detection system. User bulletin no. 2. PE Applied Biosystems, Foster City, USAGoogle Scholar
- Gavin MA, Torgerson TR, Houston E, DeRoos P, Ho WY, Stray-Pedersen A, Ocheltree EL, Greenberg PD, Ochs HD, Rudensky AY (2006) Single-cell analysis of normal and FOXP3-mutant human T cells: FOXP3 expression without regulatory T cell development. Proc Natl Acad Sci USA 103:6659–6664CrossRefPubMedGoogle Scholar
- Morgan RA, Dudley ME, Wunderlich JR, Hughes MS, Yang JC, Sherry RM, Royal RE, Topalian SL, Kammula US, Restifo NP, Zheng Z, Nahvi A, Vries CR de, Rogers-Freezer LJ, Mavroukakis SA, Rosenberg SA (2006) Cancer regression in patients after transfer of genetically engineered lymphocytes. Science 314:126–129CrossRefPubMedGoogle Scholar
- Wang C, Wen T, Routy JP, Bernard NF, Sekaly RP, Watts TH (2007a) 4–1BBL induces TNF receptor-associated factor 1-dependent Bim modulation in human T cells and is a critical component in the costimulation-dependent rescue of functionally impaired HIV-specific CD8 T cells. J Immunol 179:8252–8263PubMedGoogle Scholar