In vitro expansion of human NK cells was conducted as previously described [18 (link)]. Briefly, peripheral blood mononucleated cells (PBMCs) were isolated from healthy donors by leukapheresis and CD3+ T cells were depleted by VarioMACS (Miltenyi Biotech). T cell-depleted PBMCs were expanded at a seeding concentration of 2 × 105 cells/ml in CellGro SCGM serum-free medium (CellGenix) with 1 % autoplasma, 1 × 106 cells/ml irradiated (2,000 rad) autologous PBMCs, 10 ng/ml anti-CD3 monoclonal antibody, OKT3 (Orthoclon), and 500 IU/ml IL-2 (Proleukin) in an A-350 N culture bag (NIPRO). On day 5 of culture, NK cells were fed with fresh medium containing 500 IU/ml IL-2 and 1 % autoplasma every two days without removal of preexisting culture medium to maintain a cellular concentration at 1 ~ 2 × 106 cells/ml for 14 days. The viability of expanded NK cells was determined by propidium iodide staining.
In vitro expanded NK cells were stained with primary antibodies and analyzed by a flow cytometry using anti-CD56-PE-Cy5 (B159), anti-CD16-PE (3G8), anti-CD3-FITC (UCHT1), anti-NKp30-PE (P30-15), anti-NKp44-PE (P44-8.1), anti-NKp46-PE (9E2/NKp46), anti-DNAM-1-PE (DX11), anti-CD14-FITC (M5E2), anti-CD19-PE (HIB19) (BD Biosciences), anti-NKG2D-PE (149810) (R&D systems), anti-CD158a-PE (EB6Bf), anti-CD158b-PE (GL183), and anti-CD158e-PE (Z27.3.7) (Beckman Coulter).
In vitro expanded NK cells were stained with primary antibodies and analyzed by a flow cytometry using anti-CD56-PE-Cy5 (B159), anti-CD16-PE (3G8), anti-CD3-FITC (UCHT1), anti-NKp30-PE (P30-15), anti-NKp44-PE (P44-8.1), anti-NKp46-PE (9E2/NKp46), anti-DNAM-1-PE (DX11), anti-CD14-FITC (M5E2), anti-CD19-PE (HIB19) (BD Biosciences), anti-NKG2D-PE (149810) (R&D systems), anti-CD158a-PE (EB6Bf), anti-CD158b-PE (GL183), and anti-CD158e-PE (Z27.3.7) (Beckman Coulter).