Skip to main content
. 2020 Oct 16;11:577823. doi: 10.3389/fimmu.2020.577823

Figure 1.

Figure 1

Partial agonism of TLR4 by research-grade MPL adjuvant is species-specific. HEK-Blue reporter cells, monocytic cell-lines, and primary cells of mouse and human origin were exposed to research-grade E-MPLA to compare dose response profiles. Dose curves were performed as half-log step dilutions from a peak concentration of 10 μM with exposure of cells for 18–24 h to synthetic E. coli chemotype Lipid A, its monophosphoryl counterpart PHAD, or MPLA from Enzo Life Sciences (E-MPLA). (A, B) show normalized responses of HEK-Blue reporter cells engineered to express human TLR4 or mouse TLR4 respectively; 100% = top dose plateau of the full agonist Lipid A. (C, D) show TNFα production by human monocytic THP-1 or mouse RAW264.7 cells, respectively. (E, F) show normalized TNFα production by human PBMC or mouse BMDC, respectively; 100% = top dose plateau of the full agonist Lipid A Average values ± SD combined from three (A, B, D, F) or two (C, E) independent experiments, each performed in triplicate, are shown along with shaded regions that indicate the 99% confidence intervals within which the true population means should occur 99% of the time. In each paired comparison research-grade MPLA-E scored as a partial agonist of human TLR4 not mouse TLR4, relative to the full agonists Lipid A (full/potent) and PHAD (full/weak).