Fig. 5

GPR43 stimulation enhances the retention of TCRαβ⁺ IEL into the colonic epithelium. A–F IEL were isolated from Cd45.1^+/+ congenic mice and then treated ex vivo with 1.5 μM 4-CMTB (blue) or left untreated (black) for 1 h. Afterwards, cells were i.v. transferred into Rag1^−/− Cd45.2^+/+recipient mice, and 3 weeks later the number of cells expressing CD45.1, TCRβ, CD4, CD8αα, CD8αβ was analysed in IEL. A Schematic illustration of Cd45.1^+/+ IEL adoptive transfer into Rag1^−/− recipients. B Representative dot plots analysing the percentage of donor and recipient cells. C Percentage of CD45.1⁺ live cells detected in Rag1^−/− recipients. Absolute numbers of CD45.1⁺ (D), TCRβ⁺ (E) and donor T-cells subsets (F) isolated from the intraepithelial compartment of Rag1^−/− recipient mice. Data were obtained from 6–7 mice per group. Each symbol represents data obtained from an individual mouse. (G-I) IEL were isolated from Cd45.1^+/+ congenic mice, loaded with CTV, treated or not with 1.5 μM 4-CMTB for 1 h and then transferred into Rag1^−/− Cd45.2^+/+recipient mice. One week later the extent of T-cell proliferation was analysed in IEL. G Schematic illustration. H, I The proliferation of donor cells was determined as the dilution of CTV-associated fluorescence in CD45.1⁺ IEL. H Quantification of the MFI associated to CTV immunostaining. Each symbol represents data obtained from an individual mouse. C, D, E, F, H Mean ± SD are indicated. *, p < 0.05; by unpaired Student’s t-test. ns, non-significant. I Representative histogram of CTV associated fluorescence