The Many Faces of IL-7: From Lymphopoiesis to Peripheral T Cell Maintenance
Open Access
- 1 June 2005
- journal article
- review article
- Published by The American Association of Immunologists
- Vol. 174 (11), 6571-6576
- https://doi.org/10.4049/jimmunol.174.11.6571
Abstract
IL-7 is well known as a lymphopoietic cytokine, but recent studies have also identified a critical role for IL-7 in peripheral T cell homeostasis. IL-7 is well poised to serve as a homeostatic cytokine because it is produced by resting stromal cells, the IL-7R is present on most T cells, and IL-7 down-regulates its own receptor. These features allow IL-7 to signal large numbers of resting T cells and to be efficiently used when supplies are limiting. Consistent with this, in normal hosts, IL-7 is required for survival of naive T cell populations, and IL-7 contributes to homeostatic cycling of naive and memory cells. In addition, lymphopenic hosts accumulate increased levels of IL-7, and the supranormal levels are largely responsible for inducing homeostatic peripheral expansion in response to lymphopenia. Thus, IL-7 plays critical and nonredundant roles in both T cell lymphopoiesis and in maintaining and restoring peripheral T cell homeostasis.Keywords
This publication has 72 references indexed in Scilit:
- Dynamic regulation of IL-7 receptor expression is required for normal thymopoiesisBlood, 2004
- Recombinant Interleukin-7 Induces Proliferation of Naive Macaque CD4+and CD8+T Cells In VivoJournal of Virology, 2004
- A Role for Thymic Stromal Lymphopoietin in CD4+ T Cell DevelopmentThe Journal of Experimental Medicine, 2004
- Continued maturation of thymic emigrants in the peripheryNature Immunology, 2004
- Interleukin 7 Regulates the Survival and Generation of Memory CD4 CellsThe Journal of Experimental Medicine, 2003
- Endogenous IL-7 is associated with increased thymic volume in adult HIV-infected patients under highly active antiretroviral therapyAIDS, 2003
- Thymopoiesis independent of common lymphoid progenitorsNature Immunology, 2003
- Interleukin (IL)-15 and IL-7 Jointly Regulate Homeostatic Proliferation of Memory Phenotype CD8+ Cells but Are Not Required for Memory Phenotype CD4+ CellsThe Journal of Experimental Medicine, 2002
- Designing and Maintaining the Mature TCR Repertoire: the Continuum of Self-Peptide:Self-MHC Complex RecognitionImmunity, 1999
- Interleukin 4 (IL-4) or IL-7 Prevents the Death of Resting T Cells: Stat6 Is Probably Not Required for the Effect of IL-4The Journal of Experimental Medicine, 1997