The incidence of cholangiocellular carcinoma (CCC) is increasing worldwide. Using a transgenic mouse model, we found that expression of the intracellular domain of Notch 1 (NICD) in mouse livers results in the formation of intrahepatic CCCs. These tumors display features of bipotential hepatic progenitor cells, indicating that intrahepatic CCC can originate from this cell type. We show that human and mouse CCCs are characterized by high expression of the cyclin E protein and identified the cyclin E gene as a direct transcriptional target of the Notch signaling pathway. Intriguingly, blocking γ-secretase activity in human CCC xenotransplants results in downregulation of cyclin E expression, induction of apoptosis, and tumor remission in vivo.

The outcome of viral infections is dependent on the function of CD8+ T cells which are tightly regulated by costimulatory molecules. The NK cell receptor 2B4 (CD244) is a transmembrane protein belonging to the Ig superfamily which can also be expressed by CD8+ T cells. The aim of this study was to analyze the role of 2B4 as an additional costimulatory receptor regulating CD8+ T cell function and in particular to investigate its implication for exhaustion of hepatitis C virus (HCV)-specific CD8+ T cells during persistent infection. We demonstrate that (i) 2B4 is expressed on virus-specific CD8+ T cells during acute and chronic hepatitis C, (ii) that 2B4 cross-linking can lead to both inhibition and activation of HCV-specific CD8+ T cell function, depending on expression levels of 2B4 and the intracellular adaptor molecule SAP and (iii) that 2B4 stimulation may counteract enhanced proliferation of HCV-specific CD8+ T cells induced by PD1 blockade. We suggest that 2B4 is another important molecule within the network of costimulatory/inhibitory receptors regulating CD8+ T cell function in acute and chronic hepatitis C and that 2B4 expression levels could also be a marker of CD8+ T cell dysfunction. Understanding in more detail how 2B4 exerts its differential effects could have implications for the development of novel immunotherapies of HCV infection aiming to achieve immune control.

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Neuropeptides such as substance P (SP) and related peptides are supposed to act as mast cell agonists, and thus as mediators of neuroimmune interactions. The data supporting this hypothesis were obtained mostly from rodent experiments. Here, we studied for the first time the effect of SP and other peptides on mediator release in human intestinal mast cells, either unpurified or enriched to 85-99% purity. We found that SP at 0.1-100 micromol L(-1), or other peptides including neurokinin A and B, calcitonin gene-related peptide, vasoactive intestinal peptide and serotonin at 1 micromol L(-1) do not induce release of mediators such as histamine, sulphidoleukotrienes, and tumour necrosis factor alpha. The peptides also failed to cause mediator release in mast cells isolated from inflamed tissue derived from Crohn's disease. Using reverse transcriptase-polymerase chain reaction, flow cytometry and immunohistochemistry, we could show that human intestinal mast cells do not express the tachykinin receptors NK-1, NK-2, or NK-3 under basal conditions. However, upon stimulation by immunoglobulin E (IgE) receptor-crosslinking, which induces an extensive mediator release reaction, a subpopulation of mast cells clearly expressed NK-1, the SP receptor. In conclusion, our data show that SP and other neuropeptides do not act as secretagogues in human intestinal mast cells that have not been pre-activated by IgE receptor-crosslinking.

Being an integral part of basic, translational and clinical research, the demand for primary human hepatocytes (PHH) is continuously growing while the availability of tissue resection material for the isolation of metabolically competent PHH remains limited. To overcome current shortcomings, this study evaluated the use of explanted diseased organs from liver transplantation patients as a potential source of PHH. Therefore, PHH were isolated from resected surgical specimens (Rx-group; n = 60) and explanted diseased livers obtained from graft recipients with low labMELD-score (Ex-group; n = 5). Using established protocols PHH were subsequently cultured for a period of 7 days. The viability and metabolic competence of cultured PHH was assessed by the following parameters: morphology and cell count (CyQuant assay), albumin synthesis, urea production, AST-leakage, and phase I and II metabolism. Both groups were compared in terms of cell yield and metabolic function, and results were correlated with clinical parameters of tissue donors. Notably, cellular yields and viabilities were comparable between the Rx- and Ex-group and were 5.3±0.5 and 2.9±0.7×106 cells/g liver tissue with 84.3±1.3 and 76.0±8.6% viability, respectively. Moreover, PHH isolated from the Rx- or Ex-group did not differ in regards to loss of cell number in culture, albumin synthesis, urea production, AST-leakage, and phase I and II metabolism (measured by the 7-ethoxycoumarin-O-deethylase and uracil-5′-diphosphate-glucuronyltransferase activity). Likewise, basal transcript expressions of the CYP monooxygenases 1A1, 2C8 and 3A4 were comparable as was their induction when treated with a cocktail that consisted of 3-methylcholantren, rifampicin and phenobarbital, with increased expression of CYP 1A1 and 3A4 mRNA while transcript expression of CYP 2C8 was only marginally changed. In conclusion, the use of explanted diseased livers obtained from recipients with low labMELD-score might represent a valuable source of metabolically competent PHH which are comparable in viability and function to cells obtained from specimens following partial liver resection.

In the original article, which shows that the expression of Notch-ICD leads to the formation of intrahepatic cholangiocarcinomas, there is a duplication of actin blots in Figures 2G, 6F, and S2F.

Background and aims: Transforming growth factor b1 (TGF-b1) is expressed in the healthy human intestine and controls mucosal immune responses and inflammation by regulating the function of lymphocytes, macrophages, dendritic cells, and eosinophils. Here, we asked whether human intestinal mast cells (MC) might also be subject to immunoregulation by TGF-b1. Methods: MC were isolated from the intestinal mucosa, purified, and cultured in vitro in the presence of stem cell factor (SCF) with or without TGF-b1. Growth characteristics, phenotype, and immunological mediator release of MC were analysed by reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, western blot, and different immunoassays, respectively. Results: TGF-b1 dose dependently (ED50 < 0.1 ng/ml) inhibited SCF dependent growth of human intestinal MC by both enhancing apoptosis and decreasing proliferation. In parallel, TGF-b1 increased the percentage of connective tissue-type MC expressing tryptase and chymase while downregulating expression of the receptors for IgE and SCF. Furthermore, TGF-b1 dramatically changed the profile of mediators released by MC following IgE receptor crosslinking. Release of histamine, cysteinyl-leukotrienes, and tumour necrosis factor a was strongly reduced whereas prostaglandin D2 generation and cyclooxygenase 1 and 2 expression were upregulated by TGF-b1. Conclusions: Our data indicate that TGF-b1 acts as a novel potent inhibitor and modulator of human intestinal MC effector functions. The change in MC mediator release profile and protease expression induced by TGF-b1 might be of relevance for the control of MC associated disorders of the intestine such as allergic reactions, Crohn's disease, irritable bowel syndrome, and parasitic infection.

114 patients received a standard and 75 patients an extended resection of ductal pancreatic carcinoma at the Hanover Medical School, Germany, from 1971 until 1993. Standard pancreatic resections were combined with vascular resection and reconstruction in 46 and additional organ resections in 45 cases. Vascular resections affected the mesentericoportal vein in 37, the common hepatic in 10 and the superior mesenteric artery in 7 cases. Pancreas resections were combined with total gastrectomy in 23, partial colectomy in 17, hemihepatectomy in 14, adrenalectomy in 8 and nephrectomy in 5 patients. Curative resections could be accomplished in 86% of patients without and 81% with extended resections. Additional vascular resections neither increased the operative risk nor deteriorated the long-term prognosis after resection. Additional organ resections, however, significantly increased the risk of lethality and impaired the long-term prognosis. Especially resections of synchronous hepatic metastases and colectomies were associated with a poor survival probability.