Regenerating Gene Protein as a Novel Autoantigen in the Pathogenesis of Sjögren’s Syndrome

Sjögren’s syndrome, an autoimmune disease characterized by exocrine gland dysfunction leading to dry mouth and dry eye diseases, is typified by lymphoplasmacytic infiltrations and a progressive destruction of the salivary and lacrimal glands. Despite an ever-increasing focus on identifying the underlying etiology of Sjögren’s syndrome, the factors that initiate this autoimmune disease and the mechanisms that cause the subsequent exocrine gland dysfunction remain a mystery. The original explanatory concept for the pathogenesis of Sjögren’s syndrome proposed a specific, self-perpetuating, immune-mediated loss of acinar and ductal cells as the principal cause of salivary gland dysfunction. We highlight the possible involvement of regenerating gene (Reg) in the regeneration and destruction of salivary gland acinar and ductal cells in Sjögren’s syndrome. The Reg gene was originally isolated as a gene specifically overexpressed in regenerating pancreatic islets and constitutes a growth factor family (Reg family). We describe how salivary gland dysfunction is initiated and maintained and how it can be regenerated or progressed, mediated by the Reg gene, Reg protein, and anti-REG autoantibodies in Sjögren’s syndrome. OPEN ACCESS Antibodies 2015, 4 410