Compositions and methods for differentiating stem cells into NK cells

1. A method for generating Natural Killer (NK) cells from pluripotent stem cells, the method comprising:

(a) culturing a population of pluripotent stem cells in a first medium comprising a ROCK inhibitor under conditions sufficient to form aggregates;

(b) culturing the aggregates in a second medium comprising BMP-4;

(c) culturing the aggregates in a third medium comprising BMP-4, FGF2, a WNT pathway activator, and Activin A;

(d) culturing the aggregates in a fourth medium comprising FGF2, VEGF, TPO, SCF, IL-3, FLT3L, and an activin/nodal inhibitor to form a cell population comprising hematopoietic stem and progenitor cells (HSPCs);

(e) culturing the cell population in a fifth medium comprising FGF2, VEGF, TPO, SCF, IL-3 and FLT3L;

(f) culturing the cell population in a sixth medium comprising IL-3, IL-7, FLT3L, IL-15 and SCF;

(g) culturing the cell population in a seventh medium comprising IL-7, FLT3L, IL-15 and SCF; and

(h) culturing the cell population in an eighth medium comprising IL-7, FLT3L, IL-15, and SCF for a time sufficient to generate NK cells.

2. The method of claim 1 , wherein culturing the cell population in the sixth medium in step (f) results in the formation of progenitor cell population comprising common lymphoid progenitor (CLP) cells.

3. The method of claim 2 , wherein the progenitor cell population comprises at least about 15% of CLP cells and/or wherein the CLP cells express CD7 and CD45.

4. The method of claim 1 , wherein the ROCK inhibitor is thiazovivin or Y27632; the WNT pathway activator is CHIR-99021 and/or the activin/nodal inhibitor is SB-431542.

5. The method of claim 1 , wherein the second medium further comprises a ROCK inhibitor and/or the eighth medium further comprises nicotinamide.

6. The method of claim 1 , wherein (a) comprises culturing for 12-48 hours; (b) comprises culturing for up to 24 hours; (c) comprises culturing for 1-3 days; (d) comprises culturing for 1-3 days; (e) comprises culturing for 1-3 days; (f) comprises culturing for at least 6 days and up to 8 days; (g) comprises culturing for up to 6 days; (h) comprises culturing for at least 6 days and up to 10-16 days total; or any combination of (a), (b), (c), (d), (e), (f), (g), or (h).

7. The method of claim 6 , wherein: (a) comprises culturing for 16-20 hours; (b) comprises culturing for 6-10 hours; (c) comprises culturing for 2 days; (d) comprises culturing for 2 days; (e) comprises culturing for 2 days; (f) comprises culturing for 6-8 days; (g) comprises culturing for 6 days; and (h) comprises culturing for 8-16 days.

8. The method of claim 1 , wherein the method is carried out under suspension agitation.

9. The method of claim 1 , wherein the sixth, seventh and eighth media comprise human serum, zinc sulfate, ethanolamine, glucose, or any combination thereof, and/or the sixth, seventh and eighth media comprise DMEM (high glucose)/F12 medium, and a supplement of human serum, zinc sulfate, ethanolamine, glucose or any combination thereof.

10. The method of claim 1 , wherein the third medium is added to the second medium at a 1:1 ratio.

11. The method of claim 1 , wherein the fourth media comprises 20 ng/mL FGF, 20 ng/mL VEGF, 20 ng/mL TPO, 100 ng/mL SCF, 40 ng/mL IL-3, 10-20 ng/mL FLT3L, and 5 μM SB-431542.

12. The method of claim 1 , wherein the fifth medium comprises 20 ng/mL FGF, 20 ng/mL VEGF, 20 ng/mL TPO, 100 ng/mL SCF, 40 ng/mL IL-3, and 10-20 ng/mL FLT3L.

13. The method of claim 1 , wherein the sixth media comprises 20 ng/mL IL-7, 10-20 ng/mL FLT3L, 10-20 ng/mL IL-15, 20 ng/mL SCF, and 5 ng/mL IL-3.

14. The method of claim 1 , wherein the seventh medium comprises 20 ng/mL TL-7, 10-20 ng/mL FLT3L, 10-20 ng/mL IL-15, and 20 ng/mL SCF.

15. The method of claim 1 , wherein the eighth medium comprises 10-20 ng/mL IL-7, 5-20 ng/mL FLT3L, 10-30 ng/mL IL-15, and 20-40 ng/mL SCF.

16. The method of claim 15 , wherein the eighth medium further comprises 6.5 mM nicotinamide.

17. The method of claim 1 , wherein the NK cells express (a) at least one of CD56 or CD45 and/or (b) at least one of: an activating receptor, an inhibitory receptor or a co-receptor.

18. The method of claim 17 , wherein the at least one activating receptor is selected from the group of NKp44, NKp46, NKG2D, CD16, KIR2DL4, NKp30, and any combination thereof, the at least one inhibitory receptor is selected from the group of NKG2A, KIR3DL2, and any combination thereof, and/or the at least one co-receptor is CD94.

19. The method of claim 1 , wherein the NK cells comprise at least one function associated with endogenous NK cells.

20. The method of claim 19 , wherein the at least one function comprises (a) the ability to induce cell lysis and cell death of a target cell; (b) degranulation; or (c) a combination thereof.

21. The method of claim 20 , wherein degranulation comprises (a) release of perforin and granzyme B; (b) expression of CD107a on the cell surface of an NK cell; or (c) a combination thereof.

22. The method of claim 1 , wherein the NK cells are generated without sorting CD34 + cells from the cell population.

23. The method of claim 1 , wherein the population of pluripotent stem cells is a population of engineered cells.

24. The method of claim 23 , wherein the stem cells are genetically modified by an RNA-guided endonuclease system.

25. The method of claim 24 , wherein the RNA-guided endonuclease system is a CRISPR system comprising a CRISPR nuclease and a guide RNA.

26. The method of claim 1 , wherein the pluripotent stem cells are induced pluripotent stem cells (iPSC), embryonic stem cells (ESC), or adult stem cells (ASC).

27. The method of claim 26 , wherein the pluripotent stem cells are mammalian cells.

28. The method of claim 27 , wherein the mammalian cells are human cells.

29. A method comprising administering to a subject a plurality of NK cells generated by the method of claim 1 .