Extended Data Fig. 7: Characteristics of endogenous intestinal metabolites that activate the CAR LBD.
From: CAR directs T cell adaptation to bile acids in the small intestine
a, Mean ± s.e.m. activation (triplicate samples) of recombinant hRXRα LBD homodimers, determined by TR-FRET in the presence of TC (blue) or 9-cis retinoic acid (RA; red). Median effective concentration (EC50) of 9-cis RA-dependent hRXRα LBD homodimer activation is indicated. Representative of more than five independent experiments. b, Mean ± s.e.m. activation (n = 3) of hRXRα LBD homodimers, determined by TR-FRET as in a, in the presence of titrating concentrations of siLC, bile, cLC or serum from wild-type B6 mice. NS, not significant by one-way ANOVA with Dunnett’s correction for multiple comparisons. c, Mean ± s.e.m. activation (n = 3) of CAR–RXR LBD heterodimers, determined by TR-FRET, in the presence of titrating concentrations of siLC isolated from wild-type B6 mice housed under specific pathogen-free (SPF) or germ-free (GF) conditions and pre-treated with or without cholestyramine (CME) to deplete free bile acids. ****P < 0.0001, one-way ANOVA with Dunnett’s correction for multiple comparisons. a–c, The bars for each tissue extract indicate dilution series (left to right): diluent (PBS) alone; 0.01%, 0.1%, 1%. Data are shown from three independent experiments using extracts from different wild-type mice, with each concentration from each individual mouse run in triplicate. d, Mean ± s.e.m. TR-FRET signals (n = 3) of CAR–RXR LBD heterodimers in the presence of titrating concentrations of individual bile acid (BA) species. NS, not significant by one-way ANOVA with Dunnett’s correction for multiple comparisons. The bars for bile acids indicate concentrations (left to right): vehicle (DMSO), 10 μM, 100 μM, 1,000 μM. Data are shown from three independent experiments, in which each bile acid concentration was run in triplicate.
