Abstract
BackgroundRegulatory T cells (Tregs) expressing the transcription factor FOXP3 are crucial mediators of self-tolerance, preventing autoimmune diseases but possibly hampering tumor rejection. Clinical manipulation of Tregs is of great interest, and first-in-man trials of Treg transfer have achieved promising outcomes. Yet, the mechanisms governing induced Treg (iTreg) differentiation and the regulation of FOXP3 are incompletely understood.ResultsTo gain a comprehensive and unbiased molecular understanding of FOXP3 induction, we performed time-series RNA sequencing (RNA-Seq) and proteomics profiling on the same samples during human iTreg differentiation. To enable the broad analysis of universal FOXP3-inducing pathways, we used five differentiation protocols in parallel. Integrative analysis of the transcriptome and proteome confirmed involvement of specific molecular processes, as well as overlap of a novel iTreg subnetwork with known Treg regulators and autoimmunity-associated genes. Importantly, we propose 37 novel molecules putatively involved in iTreg differentiation. Their relevance was validated by a targeted shRNA screen confirming a functional role in FOXP3 induction, discriminant analyses classifying iTregs accordingly, and comparable expression in an independent novel iTreg RNA-Seq dataset.ConclusionThe data generated by this novel approach facilitates understanding of the molecular mechanisms underlying iTreg generation as well as of the concomitant changes in the transcriptome and proteome. Our results provide a reference map exploitable for future discovery of markers and drug candidates governing control of Tregs, which has important implications for the treatment of cancer, autoimmune, and inflammatory diseases.
Highlights
Regulatory T cells (Tregs) expressing the transcription factor Forkhead Box P3 (FOXP3) are crucial mediators of self-tolerance, preventing autoimmune diseases but possibly hampering tumor rejection
Human in vitro generated induced Treg (iTreg) show robust expression of Treg signature molecules such as FOXP3 and Eos To gain a better understanding of human FOXP3 induction, we induced iTregs from naïve CD4+ T cells allowing for the detection of iTreg signatures at the differentiated state and of events preceding FOXP3 expression, which in the human system is only possible with in vitro assays
To identify robust and generic molecular events driving FOXP3 induction, we interrogated iTregs induced by four different protocols in parallel
Summary
Regulatory T cells (Tregs) expressing the transcription factor FOXP3 are crucial mediators of self-tolerance, preventing autoimmune diseases but possibly hampering tumor rejection. The mechanisms governing induced Treg (iTreg) differentiation and the regulation of FOXP3 are incompletely understood. Immunological tolerance to self and innocuous foreign antigens is maintained by a fine-tuned balance of several immune cells, with an indispensable non-redundant role for both thymic regulatory T cells (tTregs) and peripherally induced Tregs (pTregs) [1,2,3]. Naturally-occurring Tregs (nTregs) comprise tTregs and pTregs, both of which suppress other immune cells and express the transcription factor (TF) Forkhead Box P3 (FOXP3). Most known regulators of FOXP3 are not specific to Tregs but are, rather, factors of general importance in T cells and other immune cells. FOXP3 regulation is incompletely understood in the human system despite accumulating evidence for differing FOXP3 regulation in mice versus human such as activation-induced low-level FOXP3 expression in human but not murine conventional T cells [4, 6, 7] and expression of different FOXP3 isoforms in human Tregs [8,9,10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
