Figure 4.

Response of NLRP3-deficient Thp-1 monocyte/macrophage cells (Thp-1 dNLRP3) to live H. pylori and pure ADP-heptose. (A, B) show IL-8 secretion by co-incubated, NLRP3-deficient Thp-1 cells. (A) Thp-1 NLRP3def cells co-incubated with live H. pylori bacteria of different genotypes at MOI 5 for 20 h in 24 well format (B) Thp-1 dNLRP3 cells co-incubated with H. pylori ETL (50 µl/well) from OD₆₀₀ = 2 in 24-well plate for 20 h. As controls, for TLR (3) activation, PAMCys at 400 ng/well, and for ALPK1 activation, ADP-heptose at 5 µM, respectively, were added in parallel experimental conditions. (C) IL-1β secretion by NLRP3def Thp-1 cells co-incubated with live H. pylori variants as in (A). Results of one representative experiment out of three independent experiments are shown in each panel. Cell responses in (A–C) were quantitated using cytokine ELISA. Cells were not primed before adding the respective stimuli. IL-8 was not decreased (rather increased) in NLRP3-deficient cells upon H. pylori co-incubation, while IL-1β was significantly decreased and lost the CagT4SS-and heptose-dependent phenotype upon deficiency of NLRP3. Statistical differences were calculated by unpaired student’s t-test. Significant p values: ****p < 0.0001; *p < 0.05; ns is non-significant.