Fig. 1

The actions of βγ-CAT were inhibited by AGSLs (gangliosides and sulfatides) via direct interactions. a THP-1 cells were treated with gradient concentrations of neuraminidase and then incubated with βγ-CAT. The IL-1β concentration in the supernatant was then measured by ELISA. *P < 0.05 and **P < 0.01 versus control by using unpaired two-tailed Student’s t-test (n = 3). b THP-1 cells were treated with different types of glycosidase and then incubated with βγ-CAT. The IL-1β concentrations in the supernatant was measured by ELISA. NS, not significant versus control by using unpaired two-tailed Student’s t-test (n = 3). c FITC-labeled βγ-CAT was incubated with different concentrations of gangliosides. The membrane binding of βγ-CAT to THP-1 cells was determined by flow cytometry. The untreated cells were used as a negative control. d βγ-CAT was incubated with different concentrations of gangliosides and added to THP-1 cells. The oligomerization of βγ-CAT was detected by western blotting. The immunoblots are representative of three independent experiments, the original images of immunoblots are shown in Supplementary Figure 7. e FITC-labeled βγ-CAT was incubated with different concentrations of sulfatides and then mixed with THP-1 cells. The membrane binding of βγ-CAT was determined by flow cytometry, the untreated cells were used as a negative control. f βγ-CAT was incubated with different concentrations of sulfatides, then mixed with THP-1 cells. The oligomerization of βγ-CAT was detected by western blotting. The immunoblots are representative of three independent experiments, the original images of immunoblots are shown in Supplementary Figure 7. g βγ-CAT was incubated with different concentrations of lipids and then added to LPS-primed THP-1 cells. The IL-1β concentrations in the supernatant were measured by ELISA. *P < 0.05, **P < 0.01 and ***P < 0.001 represent gangliosides and sulfatides versus sphingomyelin by two-way ANOVA with Bonferroni correction (n = 3). h, i The direct interaction between βγ-CAT and gangliosides (h) or sulfatides (i) was determined using a BLI assay. The BLI interaction curves are representative of three independent experiments. Bars represent the mean ± SD from three independent experiments per condition in a, b and g