Abstract
Much data support an essential role for interleukin (IL)-2 in immune tolerance. This idea is much different from the early paradigm in which IL-2 is central for protective immune responses. This change in thinking occurred when a T regulatory cell defect was shown to be responsible for the lethal autoimmunity associated with IL-2/IL-2R deficiency. This realization allowed investigators to explore immune responses in IL-2-nonresponsive mice rendered autoimmune-free. Such studies established that IL-2 sometimes contributes to optimal primary immune responses, but it is not mandatory. Emerging findings, however, suggest an essential role for IL-2 in immune memory. Here, the current understanding of the dual role of IL-2 in maintaining tolerance and contributing to immunity in vivo is reviewed with some emphasis on T regulatory cell production and homeostasis. Also discussed are implications of this new appreciation concerning the immunobiology of IL-2 with respect to targeting IL-2 or its receptor in immunotherapy.
Original language | English (US) |
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Pages (from-to) | 453-479 |
Number of pages | 27 |
Journal | Annual Review of Immunology |
Volume | 26 |
DOIs | |
State | Published - May 5 2008 |
Keywords
- IL-2
- Immune memory
- Immune tolerance
- T effector cell
- T regulatory cell
ASJC Scopus subject areas
- Immunology