The mechanisms by which CTLs enter and are retained in non-lymphoid tissue are not well-characterized. Using a novel transgenic mouse expressing the NKG2D ligand RAE1ϵ in β-islet cells of the pancreas, we found RAE1 expression was sufficient to induce the recruitment of adoptively transferred CTLs to islets. This was dependent on NKG2D expression by the CTLs and independent of antigen recognition. While transgenic mice did not develop diabetes, RAE1 expression was sufficient to induce insulitis in older, unmanipulated transgenic mice that was enhanced by viral infection and pancreatic inflammation. Surprisingly, the recruitment of CTLs resulted in the subsequent recruitment of a large number of endogenous lymphocytes. These results demonstrate that the expression of NKG2D ligands in islets is sufficient to recruit CTLs and induce a significant insulitis.
- Copyright © 2011 by The American Association of Immunologists, Inc.