NKG2D expression can also be present on cancer cells and is proven to stimulate oncogenic bioenergetic metabolism, proliferation and metastases generation.
[5] For CD8+ T lymphocytes, NKG2 family expression is believed to be a marker of activated or memory T cells.
Rather, they contain a positively charged residue in their transmembrane regions by which they interact with adaptor molecules containing ITAMs, mainly DNAX-activating protein of 12 kDa (DAP-12).
[2] Inhibitory NKG2 molecules containing ITIMs recruite the Src homology 2 domain containing phosphatases SHP-1 and SHP-2, which leads to the inhibition of cytotoxicity.
Kinase activation is followed by NK cell degranulation and transcription of cytokine and chemokine genes.
This enables the monitoring of classical MHC class I expression on target cells.
[4] CD94/NKG2 and their ligands can also play a role in certain diseases, where their expression can be modified on different cell types.
Many tumors avoid the cytotoxicity by excreting soluble NKG2D ligands or secreting TGF-β, leading to the downregulation of the NKG2D expression.