These results suggest that CD40 activation during intrahepatic T cell priming converts T cell hyporesponsiveness into immunity. Figure 10 Induction of functional COR93-specific CD8+ T cell responses in HBV transgenic mice by CD40 activation. We then attempted to determine the role of professional antigen presenting cells (pAPCs) in ��CD40 induced functional differentiation of HBV-specific CD8+ www.selleckchem.com/products/GDC-0449.html T cells. To do so, HBV-transgenic mice were crossed with CD11c.DOG mice that express the human diphtheria toxin (DTX) receptor on CD11c+ cells and thus allow depletion of dendritic cells after DTX administration with no signs of toxicity [45]. Groups of three CD11c.

DOG-HBV transgenic mice were treated with DTX or saline (NaCl) every other day in combination with single administration of clodronate liposome (CLL) that is known to induce apoptosis of macrophages and DCs in vivo and in vitro [46], [47], or control liposomes (NaCl-L), yielding 4 different groups of mice (i.e. NaCl+NaCl-L, DTX+NaCl-L, CLL+NaCl, and DTX+CLL.) On day 2 after CLL or NaCl-L treatment, we analyzed the numbers of myeloid dendritic cells (mDCs; F480+CD11c+), lymphoid dendritic cells (lymDCs: F480?CD11c+), Kupffer cells (F480+CD11c?) and B cells (B220+) in the liver to determine the efficacy of pAPCs depletion. As shown in Figures 11A and 11B, DTX and CLL independently depleted mDCs in the liver and their effects were additive. (Figure 11A), while intrahepatic lymDCs were depleted only by DTX treatment (Figure 11B). Surprisingly, the number of Kupffer cells paradoxically increased when mice were treated with DTX or CLL alone and with both together (Figure 11C).

This might reflect that dendritic cell death stimulated proliferation and/or migration of Kupffer cells. None of these treatments significantly reduced the number of intrahepatic B cells (Figure 11D). To examine the impact of pAPC-depletion on ��CD40 induced functional differentiation of HBV-specific CD8+ T cells, CD11c.DOG-HBV transgenic mice that were pre-treated with DTX, CLL or DTX plus CLL, were injected with ��CD40, and 1 day later, adoptively transferred with COR93-specific na?ve T cells. The mice were sacrificed on day 7 after adoptive transfer, and the intrahepatic COR93-specific CD8+ T cells were analyzed for expansion, IFN�� producing ability and Granzyme B (GrB) expression. The T cell responses were correlated with the degree of liver damage monitored by serum ALT activity. As shown in Figures 11E to 11G, Anacetrapib expansion, IFN�� producing ability, and GrB expression of COR93-specific CD8+ T cells in ��CD40 treated CD11c.