TLR8 stimulation directly matures DC and additively enhances cetuximab-mediated DC maturation. a DC were incubated with TLR8 selective agonist VTX-2337 (800 nM) or with media for 48 h. TLR8 stimulation increased DC expression of %CD80 (p < 0.001), %CD83 (p < 0.05), and CD86 median FI (p < 0.005). b DC were co-cultured with NK cells and PCI-15B HNC cells at 1:1:1 ratio. Cetuximab treatment alone enhanced DC maturation: %CD80 (p < 0.01), %CD83 (p < 0.001) and CD86 median FI (p < 0.05), as previously observed. TLR8 stimulation alone modestly enhanced DC maturation: %CD80 (p < 0.01), %CD83 (p < 0.01). Addition of TLR8 stimulation to cetuximab treatment additively enhances DC maturation: %CD80 (p < 0.01), %CD83 (0 < 0.001). Cetuximab was used at 10 μg/mL. *p < 0.05, **p < 0.01, ***p < 0.005 (C225:Cetuximab VTX:VTX-2337)