3). The total number of CD3+ T-cells was strongly elevated in 10-, 18-, and 23-week-old fra-1tg mice as compared to wildtype littermates. The fraction of T cells among all infiltrating leukocytes was 73% in 10 weeks old fra-1tg mice and remained constant in 18- (73% of polymorphonuclear cells [PMNCs]) and 23- (75% of PMNCs) week-old fra-1tg mice. Both infiltration of CD4+ T cells and CD8+ cytotoxic T cells were increased

in fra-1tg mice. Moreover, we observed a high percentage of CD4+CD25+ T cells in fra-1tg but not wildtype mice. However, these T cells were not regulatory T cells but activated T cells as determined by the absence of Foxp3 expression but expression of the activation marker CD69 (data not shown). We also determined the frequency of NK and natural killer T-cells (NKT) in learn more GW-572016 clinical trial the liver of wildtype and fra-1tg mice, as these cells are crucial for hepatic inflammation.12 Interestingly, the number of NK cells (NK1.1+CD3-) and NKT cells (NK1.1+CD3+) in the liver of fra-1tg mice was dramatically reduced at all examined timepoints (Fig. 3). NK cells displayed only about 2% and NKT cells 2%-5% of all hepatic mononuclear cells in fra-1tg mice, which was about 4-fold and 10-fold less than

wildtype mice (all timepoints, P < 0.05 between wildtype and fra-1tg mice). We then assessed the B cells in the liver of wildtype and fra-1tg mice. We found a strong and consistent reduction of CD19-positive B-cells in fra-1tg mice at all ages investigated (data not shown). Finally, we analyzed whether the changes in liver lymphocyte mafosfamide composition was a localized or generalized phenotype in fra-1tg mice. Thus, we performed FACS analysis of isolated PMNCs of 23-week-old mice. Similar to liver,

the number of CD3+ cells (+32% compared to wildtype mice, P = 0.05) was strongly increased, with a higher level of CD4+ T cells, and a remarkable reduction of CD19+ B cells (−27% of PMNCs) in fra-1tg mice. However, we could not detect any differences in NK and NKT-cell distribution in the peripheral blood between wildtype and fra-1tg mice (Fig. 3). To determine whether the observed hepatitis in fra-1tg mice leads to fibrosis and liver cirrhosis, we performed Sirius Red staining and analyzed for collagen deposition under brightfield and polarized light. In contrast to wildtype mice, livers of fra-1tg mice displayed significant fibrosis, which progressed in a time-dependent manner. In early stages (week 10), collagen deposition was observed in portal tracts and fibrosis was less evident, whereas fibrosis was widespread and bridged portal fields in older animals (week 23; Fig. 4A). A slight pericellular and perisinusoidal matrix deposition was detected by analysis of sections with polarized light and found in all examined ages of fra-1tg mice but not in controls (data not shown). Further, Fra-1tg mice demonstrated increased total hepatic collagen accumulation with a steady increase in a time-dependent manner (Fig. 4B).