Fig. 4

Bilirubin affects immune cells in the spleen. ApoE^−/− mice fed with a western-type diet were intraperitoneally injected with (bilirubin, n = 14) or without (control, n = 8) bilirubin. The animals were sacrificed after ten weeks. The spleen cells were collected and simultaneously stained with 26 metal isotope-labeled antibodies. The expression of 26 surface markers was then determined by mass cytometry. A viSNE was used to visualize the distribution of the spleen CD45⁺ immune cells from both groups. Cells on the viSNE map were colored by normalized expression of indicated surface markers. B 18 cell populations were identified and colored on the viSNE map. C A heatmap showing the normalized expression of 13 indicated markers in 18 cell populations. D Bar plots showing the frequencies of indicated populations in spleen CD45⁺ or T cells obtained from ApoE^−/− mice treated with or without bilirubin. E Dot plots (n = 22) showing the Pearson correlation coefficients for relationships between the concentrations of total bilirubin LDL, or TCHO in peripheral blood and the frequencies of indicated cell populations in the spleen. Error bars represent mean ± SD. Dots represent individual samples, n (control) = 8, n (bilirubin) = 14. *P < 0.05, **P < 0.01. Differences were determined by an unpaired t-test. Correlations were determined by a Pearson test