Naive T cell homeostasis: from awareness of space to a sense of place.
The peripheral naive T cell pool is fairly stable in number, diversity and functional competence in the absence of vigorous immune responses. However, this apparent tranquility is not an intrinsic property of T cells but involves continuous tuning of the T cell pool composition by homeostatic signals. In the past decade, studies have revealed that naive T cells rely on combinatorial signals from self-peptide-MHC complexes and interleukin-7 for their physical and functional maintenance. Competition for these factors dictates T cell 'space'. In addition, recent studies show that these and other homeostatic factors are offered to T cells on stromal cell networks, which also serve to guide T cell trafficking in secondary lymphoid organs. Such findings suggest the importance of 'place' in the perception and integration of homeostatic cues for the maintenance and functional tuning of the naive T cell pool.
Takada
Kensuke
K
Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Jameson
Stephen C
SC
D000818:Animals; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D006706:Homeostasis / Q000276:immunology*; D006801:Humans; D013601:T-Lymphocytes / Q000276:immunology*