Involvement of toll-like receptors in autoimmune sialoadenitis of the non-obese diabetic mouse.

The aim of this study was to characterize the expression of Toll-like receptors (TLRs) during the development of sialoadenitis in the non-obese diabetic mouse. Submandibular glands were dissected from non-obese diabetic mice at 4, 8, 10, 12, and 16 weeks of age. The mRNA expression levels of TLR1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, MyD88, and TRIF was quantified using real-time reverse transcription polymerase chain reaction. The mRNA expression levels in 4-week-old non-obese diabetic mice were used as controls. The expression levels of TLR1, 2, 4, and 9 were significantly higher at 8, 10, 12, and 16 weeks than the levels in the controls. The expression level of TLR3 was significantly higher at 16 weeks than in the controls. A group of mice were given drinking water containing 4.75% chloroquine starting at 4 weeks. Chloroquine caused a significant decrease in the expression of TLR1, 2, 3, 4, and 9 at 16 weeks compared with control mice who did not receive chloroquine. The areas of lymphocyte infiltration seen on serial sections of submandibular glands in the mice receiving chloroquine were significantly smaller than the areas of infiltration in control glands. Increased expression of Toll-like receptors may be involved in the development and/or progression of sialoadenitis in the non-obese diabetic mouse. Toll-like receptors may be a therapeutic target for autoimmune sialoadenitis.