Identification of an autoantibody promoting the development of Sjögren's Syndrome-like sialadenitis

We identified an autoantibody (IgGr22) directly involved in the development of sialadenitis. IgGr22 was found to promote the proliferation of pathogenic T cells. IgGr22 specifically recognized double-stranded RNA (dsRNA) and induced the activation of dendritic cells, thereby enhancing the expression of IFN signature and inflammatory genes. CD45+ cells were isolated from the salivary glands of Rag-/- mice transferred with pathogenic CD4+ T cells and recombinant autoantibody (IgGr22) related to Sjögren's syndrome using fluorescence-activated cell sorting (FACS).