Method for producing memory-like NK cells with ability to express higher levels of NCRs, cytotoxicity, and IFN-γ than NK cells in human peripheral blood

A cytokine-induced memory-like NK cell obtained by:

• 1) removing only CD3-positive T cells from monocytes to obtain CD3-negative cells;
• 2) treating the CD3-negative cells of the step 1) with a mixture of IL-15 and IL-21 for 5 to 20 days and culturing the treated CD3-negative cells;
• and
• 3) treating the cultured CD3-negative cells of the step 2) with (i) IL-12 and IL-15, (ii) IL-12 and IL-18, or (iii) IL-15 and IL-18 for 3 to 10 hours to yield the cytokine-induced memory-like NK cell;
• wherein the cytokine-induced memory-like NK cell without further treatment with cytokines in vitro or ex vivo subsequent to step 3) has the following features:
• a) an expression of NKp30 and/or CD25 in each case increased at least 5% compared to a natural killer cell isolated from peripheral blood or a known conventional memory-like natural killer cell;
• b) an expression of NKp44 decreased by at least 5% and/or an expression of KIR2DL2/3 decreased at least 3% in each case compared to a natural killer cell isolated from peripheral blood or a known conventional memory-like natural killer cell;
• and
• c) a secretion of IFN-γ increased at least 20% compared to a natural killer cell isolated from peripheral blood or a known conventional memory-like natural killer cell.