Abstract A36: The cytolytic and anti-leukemic potential of ex vivo differentiated NK cells is confined in the CD94 positive population

Adoptive transfer of allogeneic natural killer (NK) cells represents a promising treatment approach against acute myeloid leukemia (AML). We developed a cytokine-based culture method for the generation of NK cells derived from CD34+hematopoietic progenitor cells (HPC) isolated from fresh umbilical cord blood (UCB). Immuno-phenotyping of ex vivo expanded NK cells showed typical inhibitory and activating NK receptors except for CD16 and the KIR receptors. CB-derived NK cells displayed good cytolytic activity and phenotypic analysis showed that the lytic potential of these ex vivo differentiated NK was associated with their expression level of CD94. We further characterized UCB-derived NK cells by investigating in vivo their toxicity, biodistribution, and anti-leukemic potential. For this purpose, immune deficient mice were engrafted with a patient derived AML strain. We showed that in vivo only the CD94+ NK cells survive and form conjugate with leukemic blasts. The characterization of CD94+ cells and the involvement of CD94 and its ligand in the regulation of these ex vivo differentiated allogenic NK cells lytic activity will be discussed. Our findings suggest that CD94+ NK selection could be a pertinent approach to select highly functional expanded NK cells before therapeutic use. Citation Format: Salem Chouaib, Nadine Saleh Khalife, Meriem Hasmim, Yanyan Zhang, Manale Doldur, Jean Henri Bouhris, Fawzia Louache. The cytolytic and anti-leukemic potential of ex vivo differentiated NK cells is confined in the CD94 positive population [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr A36.