A pathogenic role for cystic fibrosis transmembrane conductance regulator in celiac disease (2018)
Figure 5

Figure 5. Effects of CFTR potentiators on gliadin-induced immune response in mice and in celiac human PBMC

(A-H) BALB/c mice fed with a gluten-free diet for at least 3 generations, orally challenged with vehicle or gliadin for 4 weeks (5 mg/daily for one week and then 5 mg/daily thrice a week for 3 weeks) in the presence or absence of intraperitoneal VX-770 administered 15 minutes prior gliadin challenge (n=10 mice per group of treatment). (A) Representative traces of CFTR-dependent Cl- secretion measured by forskolin (Fsk)-induced increase of chloride current (Isc (μA/cm2)) in small intestines mounted in Ussing chambers; quantification of the peak CFTR inhibitor 172 (CFTRinh172)-sensitive Isc (∆Isc) in tissue samples (n=5). Mean ± SD of samples assayed. ***p<0.001 gliadin vs gliadin+VX-770 (Student's t-test). (B) Immunoblot with anti-CFTR antibody and β-actin loading control. Densitometric analysis are mean ± SD of triplicates of independent pooled samples. **p<0.01 vehicle vs gliadin; °p<0.05, gliadin vs VX-770+gliadin (ANOVA, Bonferroni post test). (C) Plasma markers of intestinal permeability in mice. Plasma concentration of FITC-dextran 4000 (FITC-D4000) measured 1 h after gavage of a single dose of 600 mg FITCD4000 per kg body weight. Quantification of plasma concentration from n=10 mice per group of treatment expressed as mean ± SD of triplicates of independent pooled samples. ***p<0.001 vehicle vs gliadin; °°°p<0.01, gliadin vs VX-770+gliadin (ANOVA, Bonferroni post test). (D) NLRP3 expression by immunoblotting with specific antibodies in small intestines from 3 mice. Densitometric analysis are mean ± SD of triplicates of independent pooled samples. **p<0.01 vehicle vs gliadin; °p<0.05, gliadin vs VX-770+gliadin. (E-F) mRNA (E) or protein (by specific ELISA) (F) levels of IL-15, IL-21, IL-17A and IFN-γ. Mean±SD of triplicates of independent pooled samples. *p<0.05, **p<0.01, ***p<0.001 vehicle vs gliadin; °p<0.05, °°p<0.01, °°°p<0.001 gliadin vs VX-770+gliadin (ANOVA, Bonferroni post hoc test). (G-H) Transcript level of Rorc and Tbet (G) and protein levels (by specific ELISA) of IL-10 and TGF-β (H) from small intestine homogenates. Mean ± SD of triplicates of independent pooled samples. ***p<0.001 or ****p<0.0001 gliadin vs VX-770+gliadin (ANOVA, Bonferroni post hoc test).

(I-J) IFN-γ release (ELISA) in culture supernatants by PBMC from 6 celiac patients or 4 controls cultured in the lower compartment of a bidimensional co-culture model upon 24 h challenge of confluent CaCo-2 cells in the upper compartment with PT-gliadin (I) or combination of P31-43 and P57-68 (J) in presence or absence of VX-770. Mean ± SD of triplicates of independent pooled samples. ***p<0.001, PT-gliadin vs medium; °°°p<0.001, PT-gliadin vs PT-gliadin + VX-770 (n=4); ***p<0.001, P57-68 or P31-43 vs P31-43/P57-68 combination (n=6); °°°p<0.001, P57-68/P31-43 combination vs VX-770 + P57-68/P31-43 (n=3), (ANOVA, Bonferroni post hoc test).

(K) IL-10 release (ELISA) in culture supernatants by PBMC from 4 celiac patients cultured as in (J). Mean ± SD of triplicates of independent pooled samples. ****p<0.0001, P57-68/P31-43 combination vs P57-68/P31-43+VX-770 treatment (n=3) (ANOVA, Bonferroni post hoc test).

(L) IFN-γ release (ELISA) into culture supernatants by PBMC from 3 celiac patients cultured in the lower compartment of a bidimensional co-culture model upon a 24 h challenge of confluent Caco-2CFTR-KO cells in the upper compartment with a combination of P31-43 and P57-68 in the presence or absence of VX-770, as in J and K. *p<0.05, medium vs P57-68/P31-43 combination (n=3) (ANOVA, Bonferroni post hoc test).

Data information: The blots are representative of one experiment for group of treatment.