Investigation of the generation and functional maturation of regulatory T cells in vivo

This project aims to reveal the fundamental molecular mechanisms of immunological tolerance at the gene level. Immunological tolerance is a unique attribute of the adaptive immune system and suppresses excessive or unnecessary immune responses and thereby prevents the development of autoimmune disease and allergy. It is also important in the development of cancer, as the mechanisms of immunological tolerance suppress anti-tumour immunity, and thereby contribute to the development of malignancies. Regulatory T cells (Treg) are a central player of immunological tolerance. Treg suppress the activities of other T cells and thereby prevent and resolve the T cell response. Treg have been extensively studied in basic and clinical immunology, and they play roles in suppressing unwanted immune responses in autoimmune diseases, allergy, organ transplant rejection. On the other hand, the depletion of Treg can increase anti-tumour immunity. However, the suppressive mechanism of Treg is not fully known, and this lack of understanding prevents the effective application of Treg-mediated immune regulation to clinical practice.

The transcription factor Foxp3 is the key factor of Treg: it controls Treg differentiation and is required for the suppressive activity of Treg. Thus, although the suppressive mechanism of Treg is not fully known, it is a promising approach to investigate the molecular mechanisms of Foxp3-mediated T cell regulation. In this project, we will investigate the molecular mechanisms of how Foxp3 controls the suppressive function of Treg at gene level, and how T cell response to antigens promote the differentiation and maturation of Treg.

The project aims to obtain transferable knowledge and technology to industry, including the pharmaceutical industry.
The understanding of the mechanism of immunological tolerance and the suppressive mechanisms of Treg at the gene level is important not only for scientific progress but also for patency and for the development of new immunosuppressive drugs and vaccines. We also aim to use the findings of the project to improve the efficiency of the screening processes in the development of new drugs. The findings of this study will benefit broad scientific communities and contribute to health and well-being of humans and animals. In addition, this study will provide novel frameworks for systems biology, which can be used in many biological areas.

This project aims to understand the mechanisms that control the generation and functional maturation of Treg during inflammation and upon antigen recognition in vivo. To this end, the project will investigate in vivo mechanisms for Foxp3-mediated T cell regulation. We will use our novel Fluorescent Timer approach (designated as the Tocky system, see Objectives and Case) to identify and analyse new Treg and effector Treg (eTreg) by their Foxp3 transcription dynamics, and analyse their molecular mechanisms. Although preceding studies identified the factors that activate Foxp3 transcription, the physiological significance of these factors in vivo is still obscure, mainly because, there had been no efficient method to analyse the in vivo dynamics of Foxp3 transcription before the recent development of our Tocky system. Because of this, the biological relevance of induced Treg and transient Foxp3 expression is obscure. However, the Tocky system allows the investigation of the in vivo dynamics of Foxp3 transcription and Treg generation under physiological conditions. In addition, using Foxp3-Tocky, eTreg can be effectively identified and analysed.

In the proposed project, we will use the Tocky technology together with our novel double and triple transgenic mice, and thereby investigate the molecular mechanisms for how dynamically Foxp3 expression is regulated and how Foxp3 protein controls the homeostasis of Treg and eTreg differentiation in vivo.

Our work can impact on the diagnosis and treatment of patients with autoimmune disease, allergy, cancer and leukaemia, and organ transplantation. We will therefore communicate and engage with the Pharmaceutical/Biotechnological industry and the Health services. In addition, we are actively involved in Public Engagement in Science.
1) Drug discovery and Pharma industry
The project may identify target molecules and candidate substance to develop patentable substance (eg. small molecule inhibitor targeting protein-protein interaction or kinase) and IP, which may be commercially exploited to benefit the UK economy, by Biotech and Pharmaceutical industries.
2) Development of strategies to treat cancer
Understanding the molecular regulation of Treg function is relevant for developing new strategies to treat cancer patients. This is of direct relevance to industry for drug discovery (Pharma), and to the NHS and private healthcare sector.
3) Development of strategies to treat autoimmunity
Understanding the molecular regulation of Treg differentiation is relevant for developing new strategies to treat autoimmune disease patients. This is of direct relevance to industry for drug discovery (Pharma), and to the NHS and private healthcare sector.
4) Training for biomedical scientists
The project will train postdoctoral scientist in molecular biology, immunology, cell biology. In addition, it will provide a strong framework to train the postdoctoral scientist in computation skills and bioinformatics through the analysis of their own data generated by this project: Tocky flow cytometry data requires the use of command line software and bioinformatics; RNA-seq and ChIP-seq analysis will provide practical skills to the postdoctoral scientist. This will potentially benefit academic and industrial biomedical science in the UK.
5) Public understanding of science.
Through public outreach events and events for school students, the project will promote public understanding of science and inspire school students to study science.