Study on natural killer cell receptor NKG2D and its ligand MICA/B in patients with leukemia

Objective:To investigate the expression of NKG2D receptor on natural killer(NK)cells and the expression of its ligand MHC classⅠ-related chain A and B(MICA/B)whereby to analyze the mechanism for escaping killing were deteced by NK cells of leukemic cells.Methods:Detection of NKG2D receptor and MICA/B ligand were aleteced by flow cytometry analysis.Results:The expression of NKG2D receptor were significantly lower in both pretherapy and complete remission group,compared with that in health group(P0.05),moreover,it was lower in complete remission group than in pretherapy group(P0.05).The expression of MICA/B in pretherapy group was lower than that in proliferative anaemia group(P0.05);The expression of MICA/B in complete remission group,compared with that in pretherapy group,was no difference(P0.05).Conclusion:NK cell function mediated by NKG2D-MICA/B was inhibited,with possibly leads to the escape of leukemic cell from NK cell cytotoxicity;And after therapy the function of NK cells mediated by MICA/B in complete remission patients may be not ameliorated indicated by farther decrease of NKG2D-cells in the patients.