Positive and negative selection of T cells.
A functional immune system requires the selection of T lymphocytes expressing receptors that are major histocompatibility complex restricted but tolerant to self-antigens. This selection occurs predominantly in the thymus, where lymphocyte precursors first assemble a surface receptor. In this review we summarize the current state of the field regarding the natural ligands and molecular factors required for positive and negative selection and discuss a model for how these disparate outcomes can be signaled via the same receptor. We also discuss emerging data on the selection of regulatory T cells. Such cells require a high-affinity interaction with self-antigens, yet differentiate into regulatory cells instead of being eliminated.
Starr
Timothy K
TK
Center for Immunology and the Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA. star0044@umn.edu
Jameson
Stephen C
SC
Hogquist
Kristin A
KA
D000818:Animals; D002454:Cell Differentiation; D017637:Clonal Deletion; D004847:Epithelial Cells / Q000276:immunology; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D006801:Humans; D051379:Mice; D018448:Models, Immunological; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology; D014157:Transcription Factors / Q000378:metabolism
D011948:Receptors, Antigen, T-Cell; D014157:Transcription Factors