The Epigenetics of Autoimmune Diseases (Zouali/The Epigenetics of Autoimmune Diseases) || Epigenetic Modifications Associated with T Cell Tolerance

✍ Scribed by Zouali, Moncef

• Publisher: John Wiley & Sons, Ltd
• Year: 2009
• Tongue: English
• Weight: 292 KB
• Edition: 1
• Category: Article
• ISBN: 0470758619
• DOI: 10.1002/9780470743553.ch12

✦ Synopsis

The vertebrate immune system has evolved to protect against invasive pathogens, but with this adaptation comes the risk of autoimmunity, the recognition and destruction of self tissues by cells of the immune system. To avoid this problem the system has evolved active mechanisms by which tolerance is induced against self-antigens. These mechanisms include deletion of autoreactive lymphocytes, functional inactivation of lymphocytes (anergy) and suppression of inflammatory responses by a specialized subset of regulatory T cells (Tregs). The latter two modes of tolerance induction involve active transcriptional repression of pro-inflammatory cytokine genes in the affected T lymphocytes, and are likely mediated via epigenetic mechanisms. Therefore, anergy affecting the expression of the il2 and ifng genes in conventional T cells and Tregs will serve as the main subject of discussion in this review.

12.2 Epigenetic regulation of the physical structure of genomic DNA

In eukaryotic cells activation of transcription factors is often not sufficient for gene transcription. The DNA that constitutes each chromosome is wrapped around octamers of histone proteins called nucleosomes, which are in turn incorporated into higher-order structures that allow efficient packaging of the approximately 3 billion

The Epigenetics of Autoimmune Diseases Edited by Moncef Zouali