TLR7/8-L induces neutrophil activation but is not sufficient for the induction of MHC-II molecules. (A-F) Neutrophils exposed to TLR7/8-L were phenotypically characterized over time by flow cytometry. TLR7/8-L activated neutrophils as detected by upregulation of CD80 (A) and CD83 (B) as well as upregulation of the integrin CD11b (C) over time but was not sufficient for the upregulation of HLA-DR (D). TLR7/8-L enhanced CCR7 levels on neutrophils (E-F). Quantified MFIs of the indicated markers ± SEM on neutrophils over time (A-E) and representative histograms of the surface expression levels of CCR7 from a representative donor of 3 at 30 hours (F) are shown. (G) Surface expression levels of CD80, CD86, CD40, and CD83 on distinct sorted APCs after overnight exposure to TLR7/8-L. Data are presented as ratio of the MFI values between TLR7/8-L–treated and unstimulated cells ± SEM. (H-I) Representative histograms show the surface expression levels of HLA-DR (H) and CD80 (I) on human neutrophils cultured for 30 hours alone or in presence of autologous CD4⁺ T cells and pp65 with or without TLR7/8-L (2.5 μg/mL); n = 3-5 healthy human donors. *P < .05, **P < .01, ***P < .001, ****P < .0001. FMO, fluorescence minus one.