Generating intrathymic microenvironments to establish T-cell tolerance.
Alphabeta T cells pass through a series of lymphoid tissue stromal microenvironments to acquire self tolerance and functional competence. In the thymus, positive selection of the developing T-cell receptor repertoire occurs in the cortex, whereas events in the medulla purge the system of self reactivity. T cells that survive are exported to secondary lymphoid organs where they direct first primary and then memory immune responses. This Review focuses on the microenvironments that nurture T-cell development rather than on T cells themselves. We summarize current knowledge on the formation of thymic epithelial-cell microenvironments, and highlight similarities between the environments that produce T cells and those that select and maintain them during immune responses.
Anderson
Graham
G
MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. g.anderson@bham.ac.uk
Lane
Peter J L
PJ
Jenkinson
Eric J
EJ
D000818:Animals; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000502:physiology*; D006801:Humans; D007108:Immune Tolerance; D013234:Stem Cells / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology*