Human NKG2A overrides NKG2C effector functions to prevent autoreactivity of NK cells.

摘要

In April 2009, we saw a 64-year-old woman with persistent indolent proliferation of CD3~CD56+ large granular lymphocytes. She had no other clinical symptoms and no autoimmune events, and her clinical course has remained benign over 22 months. Neither clinical nor imaging studies have shown signs of lym-phoma or acute infection. IgG serology is negative for HIV-1/2, human T cell lymphotrophic virus (HTLV)-l/2, hepatitis B virus, hepatitis C virus, and HHV8, and positive for EBV, CMV, HSV, and varicella zoster virus. Most notably, we have observed an elevated lymphocyte count, ranging from 5.2 to 8.0 X 109/L, extremely unbalanced with CD3~CD56dim natural killer (NK) cells accounting for 62.0%-83.2% of lymphocytes overall (Figure 1 A).