Further, does the in vitro context of Th cell polarization recapitulate the potential variation of ERF activation downstream of TCR signalling
in vivo? For example, increased TCR signal strength can affect mature T-cell polarization (biasing towards Treg and Th17 cell lineages), and one possibility is that signal strength differences result in dosage effects of TCR-associated transcription factors, such as AP-1, IRF4 and NFAT, with intended effects on target gene expression. Furthermore, it will be important to better understand the differences in chromatin states and transcription factor function in initial polarization compared with long-term maintenance of T-cell subsets. Whereas description of enhancer characteristics is extensive – chromatin accessibility, H3K4me1, H3K27ac, p300 recruitment, physical interaction LY294002 chemical structure with promoters – it will be exciting
to learn more about the precise mechanisms of enhancer-mediated activation of transcription. Finally, we have much to learn about the graded, sequential progression of regulatory chromatin ‘maturation’, from condensed, to poised, to fully active, with augmentation R788 mw of associated gene transcription, and the specific roles of DNA- and chromatin-binding factors in this process. I appreciate ongoing support and mentorship from C. David Allis. I thank A.Y. Rudensky and members of the Allis and Rudensky laboratories for helpful discussions, and M. Sellars, A. Arvey, C. Li and R. Niec for insightful comments and input on the manuscript. S.Z.J. is supported by the National Institutes of Health
under Ruth L. Kirschstein National Research Service Award (GM100616). The author declares no conflict of interest. “
“Department of Immunobiology, Division of Immunology, Infection and Inflammatory Diseases, King′s College London, London, UK College of Life Sciences, ifenprodil University of Dundee, Dundee, UK Type 1 diabetes results from destruction of insulin-producing beta cells in pancreatic islets and is characterised by islet cell autoimmunity. Autoreactivity against non-beta cell-specific antigens has also been reported, including targeting of the calcium-binding protein S100β. In preclinical models, reactivity of this type is a key component of the early development of insulitis. To examine the nature of this response in Type 1 diabetes, we identified naturally processed and presented peptide epitopes derived from S100β, determined their affinity for the HLA-DRB1*04:01 molecule and studied T cell responses in patients, together with healthy donors. We found that S100β reactivity, characterized by IFN-γ secretion, is a characteristic of Type 1 diabetes of varying duration.