Cysteine Carboxyethylation Generates Neoantigens to Induce HLA-Restricted Autoimmunity

Scientists found that that a cysteine residue of integrin αIIb was carboxyethylated in a process that required the gut microbe metabolite 3-hydroxypropionic acid (3-HPA) and resulted in pathogenic neoantigens. Treatment of HLA-DR4 mice with either the modified protein or3-HPA resulted in autoantibody production and autoimmune pathology.