Figure 4.

Expression of the NK receptors on CD56^dim and CD56^bright NK cells after co-culturing with MSC. After co-culturing with MSC for 3 days (with 100 U/ml rhIL-2), NK cells were harvested, and surface expression of NKp30, NKp44, NKp46 and NKG2D was examined by flow cytometry, after gating for the CD56^dim and CD56^bright populations. (A) A representative dot plot of 4 independent experiments shows that among the CD56^dim NK cells, the percentage of NKp44-positive and NKp46-positive cells increase after stimulation with IL-2. L-MSC decreases the percentage of both NKp44-positive and NKG2D-positive NK cells. (B) A representative dot plot of 4 independent experiments shows that the percentage of NKp30-positive cell among the CD56^bright NK population increases after stimulation with IL-2, and this is reversed by all three types of MSC. The mean percent-positive values ± SD of the cumulative data using each of the MSC lines are presented in Table 1 .