FB-631-activated pDC and induce NK cell lytic activity against ALL cells. Enriched human pDC were stimulated with the indicated doses of FB-631 or R837. The supernatants were quantified for (A) IFNα and (B) IL-6 by ELISA. The horizontal lines represent geometric means and the error bars geometric SD factors. Repeated measure ANOVA followed by Tukey’s multiple comparisons tests was performed to assess statistical significance (n = 9, * P < 0.05, ** P < 0.01, *** P < 0.001).
Cord blood-derived pDC were co-cultured with peripheral blood NK cells in the presence or the absence of TLR agonists. The CpG ODN was used as positive control (10 μg/mL). The TLR7 agonist FB-631 was used at 300 μg. (C) Cytotoxic assays were performed against REH cells in triplicate using NK cells cultured in the absence of pDC (unst.), or in the presence of FB-631-activated pDC or CpG-activated pDC (CpG ODN). The bar graph represents the mean of specific lysis (3 independent experiments). * P < 0.05. (D) TRAIL and CD69 expression on pDC-activated or unstimulated (unst.) NK cells were assessed by flow cytometry. The means of 3 independent experiments are presented with standard deviations. ** P < 0.005.