Figure 4. The frequency of protective FoxP3^int Tregs is higher in 13R^−/− than 13R^+/+ mice.

Cells from the spleen (SP), pancreas (PN) and pancreatic lymph nodes (PLN) of 13R^+/+FoxP3-GFP or 13R^−/−FoxP3-GFP female NOD mice were stained with antibodies to CD4, CD25, and membrane bound TGFβ (mTGFβ) and the frequency of CD4⁺CD25⁺GFP^int(FoxP3^int)mTGFβ⁺ cells was analyzed by flow cytometry at the age of 6, 7 and 10 weeks. In (A) the histograms show representative FACS plots for expression of mTGFβ by cells gated on CD4 and CD25 and FoxP3^int at the indicated weeks for the SP, PLN and PN. Each bar graph show the percentage ± SD of FoxP3^int and mTGFβ expression by cells gated on CD4 and CD25 compiled from 3 independent experiments. (B) Shows the absolute number of FoxP3^intmTGFβ⁺ cells ± SEM compiled from 3 independent experiments. *p<0.05, **p<0.005 as determined by two-tailed Student’s t-test. (C) Shows the mean BGL ± SEM in 13R^+/+ NOD mice (8 per group) given sorted FoxP3^int or FoxP3^hi Tregs (4 × 10⁵ cells/mouse) at the age of 12 weeks. A group of mice that did not receive Tregs (NIL) was included for control purposes. ***p<0.0001 as determined by Kruskal-Wallis test.