Different domains of β2-glycoprotein I play a role in autoimmune pathogenesis.

Salem and colleagues evaluated the proliferative response of splenic T cells to peptides spanning the entire sequence of human β2GPI. They found that mice with induced and spontaneous SLE recognize a common T cell epitope in Domain III of β2GPI. β2GPI-reactive CD4+ T cells from the two models differed primarily in cytokine production, IFN-γ or both IL-17 and IFN-γ, respectively. This study supports the role the role of Domain III of β2GPI in T cell response of mice with SLE. β2GPI consists of 5 domains, that exist either in circular or linear form, depending on its binding to anionic phospholipids. Among these, Domain I represents the main antigenic target for autoantibodies, Domain V is responsible for the interaction with negatively charged phospholipids. Thus, different domains of β2GPI may play a role in the pathogenesis of autoimmune diseases. It may open future progress of potential peptide- or β2GPI domain-based therapeutic strategies.