Fig 4.

Mediators of NK cell cytotoxicity are reduced by VPA. (a) Enriched human NK cells were cultured overnight in the absence or presence of increasing amounts of VPA. The following day, NK cells were collected and mRNA was isolated. Following mRNA conversion to cDNA, expression of perforin (PRF1) and granzyme B (GZMB) was evaluated. A statistically significant value for VPA inhibition of perforin transcript at a concentration of 2.5 μM was P < 0.05 and at 5 μM was P < 0.01. A statistically significant value for VPA inhibition of granzyme B transcript at a concentration of 0.5 μM was P < 0.05, at 1 μM was P < 0.05, at 2.5 μM was P < 0.001, and at 5 μM was P < 0.001. P values were calculated using Student's t test. (b) Enriched human NK cells were treated as described for panel a. The following day, extracted protein was evaluated using Western blot analysis of perforin and granzyme B expression. Actin was used as a loading control. Error bars represent ± standard deviations.