In control mice infected with AdHBV k/o serum ALT activity was no

In control mice infected with AdHBV k/o serum ALT activity was not increased (Fig. 1D). Inflammatory activity in liver histology as well as CD3 T cell infiltration were only observed in AdHBV but not in AdHBV k/o infected mice (Supporting Fig. 2). Correlation with the induction of HBc-specific T cells (Fig. 1E) was consistent with the notion that immunomediated liver damage detected here is HBV specific.15 Treg activation, however, was not antigen-specific (Fig. 1F). Taken together, www.selleckchem.com/products/iwr-1-endo.html experimental infection with HBV by use of adenoviral gene transfer leads to rapid increase in Treg frequencies locally

in the liver that restrict early immunomediated liver damage directed against HBV-infected hepatocytes. To determine which cells may contribute to liver damage by killing infected hepatocytes, we analyzed the immune cell population in the liver on day 7 at the peak of liver

inflammation using flow cytometry. Importantly, we isolated significantly more LALs from livers of AdHBV-infected mice than from AdHBV k/o–infected mice or noninfected control Angiogenesis inhibitor mice. Numbers of CD4+ and CD8+ T cells as well as NK1.1+ natural killer (NK)/NK T cells among LALs increased in the liver of AdHBV infected mice (Fig. 2A). In contrast, control infection with AdHBV k/o resulted only in a minor increase of intrahepatic CD8+ T cell numbers (Fig. 2B). Treg depletion resulted in a further significant increase in numbers and the frequencies of liver-associated CD8+ and CD4+ T cells while not affecting NK1.1+ (NK and NK-T) cells (Fig. 2D, Supporting Table 1). Importantly, Dimethyl sulfoxide Treg depletion led to an increase in Lamp1+ effector T cells, indicating an increase in their cytotoxic function (Fig. 2E). To characterize in more detail the role of Tregs in the regulation of the antiviral

CD8+ T cell response, during the course of infection we followed HBc-specific T cell responses following ex vivo peptide restimulation. We isolated LALs from AdHBV-infected, Treg-depleted, and nondepleted DEREG mice and monitored interferon-γ (IFNγ), interleukin 2, and tumor necrosis factor (TNF) production by CD8+ T cells by intracellular cytokine staining. On day 7 and day 21 postinfection, Treg-depleted mice exhibited a significantly increased virus-specific CD8+ T cell response (Fig. 3A,B). The overall frequency of HBc-specific IFNγ-producing CD8+ T cells was still low at the peak of liver inflammation at day 7, but increased to 6%-8% of total CD8+ T cells until day 70 (Fig. 3A). Depletion of Tregs lead to a significant increase in total numbers of HBc-specific IFNγ- and TNF-producing CD8+ T cells already at day 7 postinfection (Fig. 3A,B). Interestingly, TNF was produced by a large number of CD8+ T cells after stimulation with HBc but also with control peptide (Supporting Fig. 3).

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