TLR-5 influences T cell activity: implications for development of Type 1 Diabetes

In mammalian and human life, one of the most important problems is to choose the best defence against microorganisms. Innate cells are good against bacteria, and T cells against virus mainly because of antibody production via T helper and B lymphocytes. Toll-like receptor 5 (TLR-5) is a regulator of this choice; when it is highly expressed, T cells are inhibited, and innate cells are favored. In activated pancreatic beta cells, TLR-5 has been found highly expressed and may therefore be protected from T cell destruction e.g., during pregnancy. We investigated mRNA from islets of Langerhans from newly diagnosed T1D patients for TLR-5. Also, we examined for polymorphisms between TLR-5, metabolic parameters, and Type 1 Diabetes (T1D). mRNA for TLR-5 was downregulated by one-third in the newly diagnosed T1D patients compared to controls. Regarding polymorphisms, two associations were found between TLR-5 and monocytes which are cells from the innate immune system. Also, a significant polymorphism was seen concerning TLR-5 and T1D. T cells are important for autoimmune diseases including T1D. In the present study we find low values of mRNA of TLR-5 which enhance T cells. We hope that the findings mentioned in this article may be influential for the understanding of how T1D develops.