{"title":"Inflammation and Thymus Ageing.","authors":"A Lepletier, A Alsharif, Ann P Chidgey","doi":"10.1159/000452903","DOIUrl":null,"url":null,"abstract":"<p><p>The thymus is primarily responsible for T cell production. However, it begins to recede in size and function, from early in life. This decreased generation of naive T cells during normal thymus ageing, or linked with pathology (i.e. chronic inflammation), leads to reduced T cell specificities, peripheral T cell imbalances, and higher susceptibilities to infections. Various clinical strategies for thymus and T cell recovery have been investigated, although no effective clinical treatments for the reconstitution of peripheral T cell diversity in severe immune deficiencies are available. The recent identification of thymic epithelial progenitor cells (TEPC) in the adult thymus will enable investigations into a new generation of therapies focused on regenerating the thymic microenvironment for diverse specificity T cell reconstitution in the elderly. The specific mechanisms underlying TEPC activation are still being investigated. Recent data point to an important role of the intrathymic transforming growth factor-β (TGF-β) circuitry. Although dual actions of this cytokine have been reported in the immune system, TGF-β signaling is transiently activated in hematopoietic stem and progenitor cells during hematopoietic regeneration. This review investigates the current strategies for thymus reactivation to replenish the peripheral T cell repertoire and potentially reverse the age-related inflammatory milieu.</p>","PeriodicalId":50428,"journal":{"name":"Frontiers of Hormone Research","volume":"48 ","pages":"19-36"},"PeriodicalIF":0.0000,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000452903","citationCount":"11","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Hormone Research","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1159/000452903","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2017/2/28 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"Medicine","Score":null,"Total":0}
引用次数: 11
Abstract
The thymus is primarily responsible for T cell production. However, it begins to recede in size and function, from early in life. This decreased generation of naive T cells during normal thymus ageing, or linked with pathology (i.e. chronic inflammation), leads to reduced T cell specificities, peripheral T cell imbalances, and higher susceptibilities to infections. Various clinical strategies for thymus and T cell recovery have been investigated, although no effective clinical treatments for the reconstitution of peripheral T cell diversity in severe immune deficiencies are available. The recent identification of thymic epithelial progenitor cells (TEPC) in the adult thymus will enable investigations into a new generation of therapies focused on regenerating the thymic microenvironment for diverse specificity T cell reconstitution in the elderly. The specific mechanisms underlying TEPC activation are still being investigated. Recent data point to an important role of the intrathymic transforming growth factor-β (TGF-β) circuitry. Although dual actions of this cytokine have been reported in the immune system, TGF-β signaling is transiently activated in hematopoietic stem and progenitor cells during hematopoietic regeneration. This review investigates the current strategies for thymus reactivation to replenish the peripheral T cell repertoire and potentially reverse the age-related inflammatory milieu.
期刊介绍:
A series of integrated overviews on cutting-edge topics
New sophisticated technologies and methodological approaches in diagnostics and therapeutics have led to significant improvements in identifying and characterizing an increasing number of medical conditions, which is particularly true for all aspects of endocrine and metabolic dysfunctions. Novel insights in endocrine physiology and pathophysiology allow for new perspectives in clinical management and thus lead to the development of molecular, personalized treatments. In view of this, the active interplay between basic scientists and clinicians has become fundamental, both to provide patients with the most appropriate care and to advance future research.