Novel animal models for Sjögren's syndrome: Expression and transfer of salivary gland dysfunction from regulatory T cell-deficient mice

IL-2 knockout (KO), IL-2Rα KO and scurfy mice lack the CD4+CD25+ regulatory T (Treg) cells and develop severe inflammation in multiple organs, although organs affected vary among these strains. We asked if salivary and lacrimal glands, the main organs affected in Sjögren's syndrome, are targeted in these strains. Severe lymphocyte and neutrophil infiltration in the salivary and lacrimal glands and a decrease in salivary secretory function were observed in IL-2 KO and IL-2Rα KO mice, but not in scurfy mice. Interestingly, transfer of lymph node cells from scurfy mice to RAG-1 KO recipients rapidly and effectively induced inflammation and loss of function in the salivary glands. Furthermore, we observed that daily LPS feeding in scurfy mice also induced inflammation in the salivary glands. Our study demonstrates several novel models for Sjögren's syndrome, including an adoptive transfer model that shows that scurfy mice have dormant salivary gland-specific autoreactive lymphocytes that can be activated by certain environmental factors, such as those present in RAG-1 KO mice.