natural killer cell tolerance induction

Definition

Target type: biologicalprocess

Tolerance induction of natural killer cells. [GOC:jal, PMID:16546094]

Natural killer (NK) cells are a type of cytotoxic lymphocyte that play a critical role in the innate immune system. While NK cells are essential for eliminating virally infected and cancerous cells, they must also be prevented from attacking healthy cells. This delicate balance is achieved through a process known as NK cell tolerance induction. Tolerance induction ensures that NK cells do not mistakenly attack healthy tissues, thus preventing autoimmune diseases.

The process of NK cell tolerance induction is complex and involves a number of different mechanisms. One key mechanism is the expression of MHC class I molecules on the surface of healthy cells. MHC class I molecules present peptides derived from intracellular proteins to NK cells. NK cells express receptors that recognize these MHC class I molecules, and this recognition signals to the NK cells that the target cell is healthy and should not be attacked.

In addition to MHC class I recognition, NK cells also express a variety of inhibitory receptors that can suppress their activation. These inhibitory receptors recognize ligands expressed on healthy cells, and their activation can prevent NK cells from killing the target cell. For example, the inhibitory receptor KIR2DL1 recognizes HLA-C molecules, while the inhibitory receptor CD94/NKG2A recognizes HLA-E molecules.

NK cell tolerance induction is also influenced by the presence of other immune cells, such as regulatory T cells (Tregs) and dendritic cells (DCs). Tregs can suppress NK cell activation and promote NK cell tolerance, while DCs can present antigens to NK cells and influence their activation state.

Dysregulation of NK cell tolerance can lead to the development of autoimmune diseases. For example, in autoimmune diseases like rheumatoid arthritis and systemic lupus erythematosus, NK cells have been shown to contribute to inflammation and tissue damage.

In summary, NK cell tolerance induction is a complex process that involves multiple mechanisms. The expression of MHC class I molecules on healthy cells, the activation of inhibitory receptors on NK cells, and the interaction of NK cells with other immune cells all contribute to preventing NK cell activation and maintaining immune homeostasis.'
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Proteins (2)

Compounds (8)