![Figure 3. In vivo expanded NK cells are potent killers, express high levels of NKG2A, and correlate with endogenous IL-15 prior to NK cell infusion. (A) Cytotoxicity of in vitro IL-2 activated NK cell products compared with PB NK cells isolated at day 14 after in vivo expansion. Cytotoxicity assay against K526 targets at various effector to target ratios. Cytotoxicity of the NK cell product (in gray; 15 infusion products; mean ± standard error of the mean [SEM]) prior to infusion compared with NK cells isolated from the PB at day 14 of those that expanded (black line; 4 subjects; showed mean ± SEM). (B) Expression of inhibitory receptors on NK cells in product and in vivo expanded NK cells at day 14. (C) Serum IL-15 levels at various time points after NK cell infusion. Comparison of IL2DT cohort patients with donor NK expansion (n = 4) vs no NK cell expansion (n = 11) and all patients not treated with IL2DT (n = 42, mean and standard deviation shown).](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/123/25/10.1182_blood-2013-10-532531/4/3855f3.jpeg?Expires=1723091772&Signature=GljlxNGArK9S995YQf1nKThn2ggX3eq96sqnm96XxfLGR~DBCqv7w859E9yy~-ODjF1F3H34LnhwQxMgVk3XozN5GyuDih8WrVoT0sWAHoQNXctWAlT1HNOgPn1qMtOSPiKLMB2-9WMv5Oo2It9yJccdSx9HI3KbGpZFv~P6Gji8Jei~GXfUtjWE6C94XcK-wRw--E8glvMIGYyob-aHtE49qaATPCVluCqtxx-b5A-6e50Oiw7gjI65Ld5w1deF7ZbFI-~R1L5yQoC8U1UjxBDPC1XA3tUWzGZKSKJMs2TD~IhLsHtFY-ZYu5mHgADnNz44QBhEu6mvsy8DLPi8mQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
In vivo expanded NK cells are potent killers, express high levels of NKG2A, and correlate with endogenous IL-15 prior to NK cell infusion. (A) Cytotoxicity of in vitro IL-2 activated NK cell products compared with PB NK cells isolated at day 14 after in vivo expansion. Cytotoxicity assay against K526 targets at various effector to target ratios. Cytotoxicity of the NK cell product (in gray; 15 infusion products; mean ± standard error of the mean [SEM]) prior to infusion compared with NK cells isolated from the PB at day 14 of those that expanded (black line; 4 subjects; showed mean ± SEM). (B) Expression of inhibitory receptors on NK cells in product and in vivo expanded NK cells at day 14. (C) Serum IL-15 levels at various time points after NK cell infusion. Comparison of IL2DT cohort patients with donor NK expansion (n = 4) vs no NK cell expansion (n = 11) and all patients not treated with IL2DT (n = 42, mean and standard deviation shown).
