Fig. 7

Levels of IAA in the peripheral blood of individuals with obesity. a Flow cytometry of p35⁺Ebi3⁺CD19⁺ cells in human peripheral blood cells after exposure to IAA, LPS, LPS+IAA, LPS + IAA + AhR inhibitor (+AHRi), LPS + IAA + PXR inhibitor+(PXRi), or LPS + IAA + NFκB inhibitor (+NFκBi) for 48 h. IsoAb, isotype control; NC, negative control. b ELISA of IL-35 in the supernatants of human peripheral blood cells after exposure to different concentrations of IAA with or without 500 ng/ml LPS or exposure to different concentrations of LPS with or without 100 mM IAA. c Immunostaining of PXR, p65, and RXRa in human peripheral blood cells after exposure to IAA + LPS for 6 h. Ctr., no stimulation. d Negative correlation between the BMI and IAA levels in sera according as determined by linear regression analysis. R2 = 0.1532. e IAA levels in the peripheral blood of subjects from different groups, BMI ≤ 18.5 (n = 42), 18.5–23.9 (n = 41), 24–26.9 (n = 43), 27–29.9 (n = 42), and ≥ 30 (n = 40). The data in a and b were from three independent experiments. Student’s t test in a, mean ± SD; analysis of variance in b; Spearman nonparametric rank test for the correlation between the IAA level and BMI in d; and the Mann–Whitney U test in e, mean ±SEM. *p < 0.05, **p < 0.01, and ***p < 0.001; NS, no significance