Jun 27, 2019 Last Updated 10:21 AM, Jun 26, 2019

Central CD4 T cell tolerance: deletion versus Treg differentiation

Published in Head news
Read 347 times
Rate this item
(0 votes)

A widely -though a little bit simplistic paradigm of central tolerance, in immunology, is that thymocytes undergo a process of deletion, during their differentiation, as they express a TCR that shows high affinity or avidity for MHC that load self-antigens. This mechanism helps eliminating autoreactive T cells that might unleash autoimmunity. However, the host of T cell precursors in the thymus is also the source of T regulatory cells (Treg), a central gear of the machinery that modulates and shapes the immune system. In this sense, Treg existence and features exposed all the limits of a model of central tolerance based on TCR affinity for MHC: indeed this theoretical approach could only partially explain the huge variety of T cells we see circulating, especially in light of paradoxical evidences such as that of Tregs partly sharing their TCR repertoire with that of conventional T cells, or the fact that they can be induced by self-antigen recognition. As it turns out, things are way more difficult to explain and the system that, in the thymus, decides the fate of CD4 T cells is rather convoluted, as Ludger Klein, Ellen A Robey and Cyi- Song Hsieh explained so eminently in Nature Reviews Immunology, last week.


The review splendidly explains the molecular mechanisms through which the immune tolerance skews CD4 thymic precursors either towards classical T cells or Treg, explaining the details of the role played on this function by the expression of  ubiquitous and tissue-restricted antigens.

Source: Nature Reviews Immunology



Image modified from The Awkward Yeti

Last modified on Friday, 07 December 2018 11:52
Login to post comments

Registered area

Thanks to the support of
merck serono biogen sanofi

Conferences & Courses

17° Corso CRNI Viva la differenza: sesso e neuroimmunologia

March 7-10, 2018 
Bergamo - Bergamo Science Center


Encefaliti Autoimmuni e Malattie Demielinizzanti Atipiche

16 febbraio 2018
Aula Magna Giorgio De Sandre


JNIInternational Brain Research Organization
Bringing Neuroscience to the World
JNIJournal of Neuroimmunology
Studies on all branches of neurosciences covering both research and clinical problems of neuroscientific interest.

This website or its third party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. If you want to know more or withdraw your consent to all or some of the cookies, please refer to the cookie policy. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies. To find out more about the cookies we use and how to delete them, see our Cookie Policy