A proinsulin 74-90-derived protease-resistant, altered peptide ligand increases TGF-beta 1 secretion in PBMC from patients with type 1 diabetes mellitus.

Proinsulin is a major diabetes-associated autoantigen. APL have been shown to manipulate the immune response of T cells. Here, we generated a lysosomal protease-resistant proinsulin 74-90-derived APL using a CS-directed amino acid modification approach.