CD159a (also known as NKG2A, encoded by the KLRC1 gene) is an inhibitory receptor present on the surface of natural killer (NK) cells and some T cells. When it binds to the HLA-E molecule, it transmits inhibitory signals and regulates the activity of immune cells. Certain viruses (such as HIV and CMV) upregulate the expression of HLA-E to bind to CD159a and inhibit the function of NK cells. Blocking the NKG2A/HLA-E pathway can restore antiviral immunity.
