Figure 5.

Scheme showing possible interaction among high and low doses of IL-2 in inducing and preventing type 1 diabetes mellitus (type 1 DM). It is proposed that high doses of IL-2 induce the activation of iPLA₂ and COX-2 that leads to the synthesis and release of PGE2 and LTB4 and other pro-inflammatory molecules that enhance the formation of free radicals leading to apoptosis of pancreatic β cells and onset of type 1 DM. On the other hand, low doses of IL-2/tumor necrosis factor-α (TNF-α) activates sPLA₂ and cPLA₂ (cPLA₂ > sPLA₂) that leads to the formation of lipoxins, resolvins, and protectins; anti-inflammatory molecules, which decrease the formation of free radicals and enhance antioxidant capacity of pancreatic β cells and prevents type 1 DM.