Tet2 Controls β cells Responses to Inflammation in Type 1 Diabetes

β cells may participate and contribute to their own demise during Type 1 diabetes (T1D). We identified a novel role of Tet2 in regulating immune killing of β cells. Tet2 is induced in murine and human β cells with inflammation but its expression is reduced in surviving β cells. Tet2-KO mice that receive WT bone marrow transplants develop insulitis but not diabetes and islet infiltrates do not eliminate β cells even though immune cells from the mice can transfer diabetes to NOD/ scid recipients. Tet2-KO β cells show reduced expression of inflammatory genes, associated with closed transcription factor binding sites. Tet2-KO recipients are protected from transfer of disease by diabetogenic immune cells. We conclude that Tet2 regulates pathologic interactions between β cells and immune cells and controls intrinsic protective pathways. Modulating TET2 may enable survival of β cells or their replacements in the setting of pathologic immune cells. ### Competing Interest Statement The authors have declared no competing interest.