Differential cytokine expression in direct and indirect co-culture of islets and mesenchymal stromal cells

Transplantation of allogenic Langerhans islets (ISL) has been employed as an alternative to pancreas transplantation to provide endogenous supply of insulin and treat hypoglycemia unawareness in type 1 diabetes. Nevertheless, the process of islets isolation exposes the islets to hypoxia and other aggressive conditions that

Direct contact between human WJMSC and pancreatic islets is required for elevated expression of a range of immune cytokines, including both those considered inflammatory, and anti-inflammatory.

In 3 series of experiments with human islets of 3 different donors, we compared the levels of a panel of cytokines measured in the supernatant of ISL cultured alone, Wharton Jelly MSC (WJMSC) cultured alone, direct co-culture of ISL-WJMSC and indirect co-culture using a permeable transwell membrane to separate ISL and WJMSC.

Comparing the profile of cytokines secreted by islets alone with islets in direct co- culture with WJMSC, we found higher expression of IL1b, IL17, IFγ, IL4, IL10, IL13, Granulocyte-macrophage colony-stimulating factor (GMCSF) and Leptin, in the supernatant of the co-cultures. In contrast, when comparing islets cultured alone with islets in indirect co-culture with MSC, we found no significant differences in the levels of cytokines we analyzed.