Figure 3. NK cell expansion and purity after repeated weekly stimulation with aAPCs expressing membrane-bound cytokines.

A, Mean expansion of CD3^neg/CD16-or-56^pos NK cells from 22 donors expanded for 21 days using aAPCs bearing mbIL15 or mbIL21. NK cells from five donors were also expanded with aAPCs expressing both mbIL15 and mbIL21. B, Mean expansion of NK cells from 4 donors expanded for 42 days using aAPCs bearing mbIL15 or mbIL21. C, Percent of CD3^pos T/NKT cells and CD3^neg/CD16-or-56^pos NK cells in the starting PBMC product (day 0) and at the end of 21 days of expansion on Clone 9.mbIL21 from 20 donors. D, Mean expansion of CD3^neg/CD16-or-56^pos NK cells on Clone 9.mbIL21 from unfractionated PBMC (n = 19), unfractionated PBMC followed by NK purification at day 14 of expansion (n = 3), or from NK cells purified from PBMC at day 0 prior to expansion (n = 13). Mean +/− SD is shown for each plot. All p values indicated are for t-test of fold expansion at the end of the expansion period.