Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 139-176 |
| Number of pages | 38 |
| Journal | Annual Review of Immunology |
| Volume | 21 |
| DOIs | |
| State | Published - Oct 7 2003 |
Keywords
- Allelic exclusion
- Differential signaling
- T cell development
- Thymocyte
- Thymus