Figure 3. Extracellular release of the pro-inflammatory cytokine TNF-α in human PCLS after 24 h of treatment with HAC1, SiO₂ or HAC1-SiO₂.

Human PCLS were treated without (control) or with increasing concentrations of either the plant-derived recombinant hemagglutinin protein HAC1 or the SiO₂ nanoparticles or the protein bound onto SiO₂ nanoparticles (ratio HAC1:SiO2 = 1∶100) or with LPS as an inflammatory control. The cytokine levels of TNF-α in PCLS culture supernatants were determined by Multiplex MSD technology. Data are presented as mean±SEM, *p<0.05, **p<0.01 & ***p<0.001 compared to untreated tissue control, ^Xp<0.05 compared to corresponding concentration of combined treatment (HAC1 vs. HAC1-SiO₂ or SiO₂ vs. HAC1-SiO₂), Friedman test and Dunn’s Multiple Comparison Post-hoc test (n = 13). HAC1 =  plant-derived recombinant hemagglutinin protein, SiO₂ = silica nanoparticles.