Figure 1. Activation, migration, entry, and infiltration of immune cells into islets during spontaneous diabetes.

A-C: Dendritic cells loaded with beta-cell antigens migrate from islets to pancreatic lymph nodes and present antigen to naïve autoreactive CD4⁺ and CD8⁺ T cells. These T cells undergo initial activation and migrate towards the pancreas via the circulation. D: Entry for CD4⁺ T cells and CD8⁺ T cells into islets and presentation (CD8⁺ T cells). Once arrested, T cells roll and extravasate via integrins and adhesion molecules. E: Insulitis development in islets. Initial macrophage infiltration occurs, followed by T cell infiltration, and the formation of peri-islet insulitis. The islet basement membrane breaks down and invasive insultis with concurrent beta-cell destruction occurs.