Fig. 2.

In vivo heparin (HI) hydrogels are associated with an increase in FoxP3⁺ Tregs and reduce diabetes onset in NOD mice. (a–d) Six-week-old NOD mice were treated with either 25,000 IU IL-2 once weekly or the same amount of IL-2 delivered in the context of a single hydrogel injection, or PBS injections as a negative control. After 1 month, mice were killed, mesenteric LNs were collected, and populations of lymphocytes were assessed by flow cytometry. In particular, the percentage of CD3⁺CD4⁺ T cells (a), the percentage of CD3⁺CD8⁺ T cells (b), CD3⁺CD4⁺FOXP3⁺ Tregs (c) and FOXP3 mean fluorescence intensity (MFI) (d) were assessed. Data are representative of two independent experiments; n=5 mice per group. Data represent mean ± SEM; *p<0.05 as determined by ANOVA followed by Šidák’s multiple comparisons test. (e) Starting at 6 weeks of age, NOD mice received either 25,000 IU IL-2 once weekly, or the same amount of IL-2 delivered in the context of a once a week hydrogel injection. PBS injections served as negative controls. Mice were then monitored weekly for diabetes onset. This treatment was administered to mice from 6 to 21 weeks of age and mice were subsequently monitored until 33 weeks of age. (f, g) Number of diabetic mice per group (f) and blood glucose (g) at 33 weeks of age, 3 months after treatment ended. Data represent mean ± SEM, n=10 mice per group. *p<0.05 as determined by ANOVA followed by Šiák’s multiple comparisons test