Role of NKp46 Expression in Cytokine Production by CD56-Positive NK Cells in the Peripheral Blood and the Uterine Endometrium

Problem To investigate the role of natural cytotoxicity receptor, NKp46 expression in cytokine-producing NK cells. Method of Study CD56+/NKp46+ NK cells from the peripheral blood and the uterine endometrium were magnetically separated. IFN-, TNF-, IL-4, IL-10, and TGF-1 expressions on NK cells were investigated using multicolor flow cytometry. Results Peripheral blood and uterine endometrial NK cells were grouped into 4 subpopulations based upon the degree of CD56 and NKp46 expressions. NKp46 expression was associated with higher frequency of cytokine-producing NK cells, including CD56dimNK cells. The percentage of TNF-+ and IL-10+ NK cells per total CD56+/NKp46+ NK cells in the uterine endometrium showed a significant correlation with those of the peripheral blood in all subpopulations, but that of IFN-+, IL-4+, and TGF-1+ NK cells showed partial correlation. Conclusion Expression of NKp46 is involved in cytokine production of CD56+ NK cells in the peripheral blood and the uterine endometrium.