Cytotoxicity function of KIR positive NK cells derived cord blood stem cells against acute lymphoblastic leukemia and acute myeloid leukemia

Abstract

Acute lymphoid (ALL) and myeloid leukemia (AML) are known to be invasive and highly lethal hematological malignancies in adults and children. Insufficiency of the present treatments and their diverse side effects lead researchers to find new and more effective therapeutic methods. Interestingly, ongoing efforts to find the best approach to optimize NK cell anti-leukemia potential shed light for the successful treatment of cancer. Of note, mature KIR+NK cell’s ability to remove HLA Class I deficient cells has been exploited in cancer immunotherapy. Material and methods: The mononuclear cells were isolated from were isolated from umbilical cord blood cells by Ficol-Paque density gradient and CD34 positive cells were enriched with MACS LS column using CD34 microbeads. Then the cells were cultured using IL-2 and IL-15 cytokines for 21 days. Flow cytometry was performed on days 7, 14, and 21. Then, NK cell cytotoxicity was evaluated by measuring expression of CD107a and secretion of IFN-γ. Results: KIR+NK cells generated efficiently from CD34 positive cord blood cells in vitro using IL-2 and IL-15 on day 14, although it was not dose dependent. KIR+NK cells derived from CD34+ cells in day 14 of culture efficiently increased apoptosis in AML and ALL cells, produced INFγ and increased CD107-a expression.