Adoptive transfer of CD3 T cells and CD4 CD44 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 CD3 T cells both efficiently induced AIP, while CD4 and CD8 T cells alone, as well as splenocytes from healthy mice, were insufficient to trigger the disease. Strikingly, CD4 CD44 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 ) on the progression of AIP in already diseased mice. Under the given experimental conditions, there was no significant suppressive effect of adoptively transferred T on pancreatic histopathology. The results of our studies suggest a key role of T cell-mediated processes in murine AIP. The effects of CD4 CD44 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.