Adoptive transfer of CD 3 + T cells and CD 4 + CD 44 high memory T cells induces autoimmune pancreatitis in MRL /MpJ mice

The immunopathogenesis of autoimmune pancreatitis ( AIP ) is poorly understood. Here, we have used MRL /MpJ mice, a model of spontaneous AIP , to address the role of cellular autoimmune processes in the initiation and progression of the disease. Therefore, different T cell subpopulations were adoptively transferred from sick to still healthy (but susceptible) MRL /MpJ mice. Unpurified splenocytes and CD 3 + T cells both efficiently induced AIP , while CD 4 + and CD 8 + T cells alone, as well as splenocytes from healthy mice, were insufficient to trigger the disease. Strikingly, CD 4 + CD 44 high memory T cells, although transferred at lower numbers than other T cells, also induced AIP in recipient mice. Employing a modified experimental design, we also evaluated the effects of regulatory T cells ( T regs ) on the progression of AIP in already diseased mice. Under the given experimental conditions, there was no significant suppressive effect of adoptively transferred T regs on pancreatic histopathology. The results of our studies suggest a key role of T cell‐mediated processes in murine AIP . The effects of CD 4 + CD 44 high memory T cells are in accordance with genetic studies of our group, which had previously implicated this cell type into the pathogenesis of AIP . In follow‐up studies, we will focus on the interplay of cellular and humoral autoimmunity in the context of AIP .