Publication Date:
2015-11-26
Description:
T-cell receptor (TCR) signalling has a key role in determining T-cell fate. Precursor cells expressing TCRs within a certain low-affinity range for complexes of self-peptide and major histocompatibility complex (MHC) undergo positive selection and differentiate into naive T cells expressing a highly diverse self-MHC-restricted TCR repertoire. In contrast, precursors displaying TCRs with a high affinity for 'self' are either eliminated through TCR-agonist-induced apoptosis (negative selection) or restrained by regulatory T (Treg) cells, whose differentiation and function are controlled by the X-chromosome-encoded transcription factor Foxp3 (reviewed in ref. 2). Foxp3 is expressed in a fraction of self-reactive T cells that escape negative selection in response to agonist-driven TCR signals combined with interleukin 2 (IL-2) receptor signalling. In addition to Treg cells, TCR-agonist-driven selection results in the generation of several other specialized T-cell lineages such as natural killer T cells and innate mucosal-associated invariant T cells. Although the latter exhibit a restricted TCR repertoire, Treg cells display a highly diverse collection of TCRs. Here we explore in mice whether a specialized mechanism enables agonist-driven selection of Treg cells with a diverse TCR repertoire, and the importance this holds for self-tolerance. We show that the intronic Foxp3 enhancer conserved noncoding sequence 3 (CNS3) acts as an epigenetic switch that confers a poised state to the Foxp3 promoter in precursor cells to make Treg cell lineage commitment responsive to a broad range of TCR stimuli, particularly to suboptimal ones. CNS3-dependent expansion of the TCR repertoire enables Treg cells to control self-reactive T cells effectively, especially when thymic negative selection is genetically impaired. Our findings highlight the complementary roles of these two main mechanisms of self-tolerance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Feng, Yongqiang -- van der Veeken, Joris -- Shugay, Mikhail -- Putintseva, Ekaterina V -- Osmanbeyoglu, Hatice U -- Dikiy, Stanislav -- Hoyos, Beatrice E -- Moltedo, Bruno -- Hemmers, Saskia -- Treuting, Piper -- Leslie, Christina S -- Chudakov, Dmitriy M -- Rudensky, Alexander Y -- P30 CA008748/CA/NCI NIH HHS/ -- R01 AI034206/AI/NIAID NIH HHS/ -- R37 AI034206/AI/NIAID NIH HHS/ -- U01 HG007893/HG/NHGRI NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2015 Dec 3;528(7580):132-6. doi: 10.1038/nature16141. Epub 2015 Nov 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Immunology Program, Ludwig Center at Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA. ; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya 16/10, Moscow 117997, Russia. ; Pirogov Russian National Research Medical University, Ostrovityanova 1, Moscow 117997, Russia. ; Central European Institute of Technology, Masaryk University, Kamenice 753/5, Brno 62500, Czech Republic. ; Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA. ; Department of Comparative Medicine, School of Medicine, University of Washington, Seattle, Washington 98195, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26605529" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Differentiation
;
Cell Lineage
;
Conserved Sequence/genetics
;
Enhancer Elements, Genetic/genetics
;
Epigenesis, Genetic
;
Female
;
Forkhead Transcription Factors/genetics
;
Introns/genetics
;
Male
;
Mice
;
Promoter Regions, Genetic/genetics
;
Receptors, Antigen, T-Cell/genetics/metabolism
;
Receptors, Interleukin-2/immunology/metabolism
;
Self Tolerance/*immunology
;
Signal Transduction
;
T-Lymphocytes, Regulatory/*cytology/*immunology/metabolism
;
Transcription Factors/deficiency
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
