Publications by authors named "Heikenwalder M"

Chronic hepatitis B virus (HBV) infection remains the number one risk factor for hepatocellular carcinoma (HCC), accounting for more than 600 000 deaths/year. Despite highly effective antiviral treatment options, chronic hepatitis B (CHB), subsequent end-stage liver disease and HCC development remain a major challenge worldwide. In CHB, liver damage is mainly caused by the influx of immune cells and destruction of infected hepatocytes, causing necro-inflammation.

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Liver cancer-also called hepatocellular carcinoma (HCC)-is the most frequent primary liver cancer in humans. As of today, it is mainly induced by chronic virus infections such as Hepatitis B and C viruses, which induce chronic hepatitis and fibrosis, the two most important conditions predisposing towards HCC development. Besides, chronic alcohol or drug consumption contributes to chronic liver injury and HCC development.

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Unlabelled: Due to its ability to inhibit prometastatic matrix metalloproteinases, tissue inhibitor of metalloproteinases (TIMP)-1 has been thought to suppress tumor metastasis. However, elevated systemic levels of TIMP-1 correlate with poor prognosis in cancer patients, suggesting a metastasis-stimulating role of TIMP-1. In colorectal cancer patients, tumor as well as plasma TIMP-1 levels were correlated with synchronous liver metastasis or distant metastasis-associated disease relapse.

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Deposition of aggregated amyloid-β (Aβ) peptide in brain is an early event and hallmark pathology of Alzheimer's disease and cerebral Aβ angiopathy. Experimental evidence supports the concept that Aβ multimers can act as seeds and structurally corrupt other Aβ peptides by a self-propagating mechanism. Here we compare the induction of cerebral β-amyloidosis by intraperitoneal applications of Aβ-containing brain extracts in three Aβ-precursor protein (APP) transgenic mouse lines that differ in levels of transgene expression in brain and periphery (APP23 mice, APP23 mice lacking murine APP, and R1.

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Systemic bacterial infection induces a hematopoietic response program termed "emergency granulopoiesis" that is characterized by increased de novo bone marrow (BM) neutrophil production. How loss of local immune control and bacterial dissemination is sensed and subsequently translated into the switch from steady-state to emergency granulopoiesis is, however, unknown. Using tissue-specific myeloid differentiation primary response gene 88 (Myd88)-deficient mice and in vivo lipopolysaccharide (LPS) administration to model severe bacterial infection, we here show that endothelial cells (ECs) but not hematopoietic cells, hepatocytes, pericytes, or BM stromal cells, are essential cells for this process.

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Non-alcoholic fatty liver disease (NAFLD) represents the most common liver disease in Western countries and often progresses to non-alcoholic steatohepatitis (NASH) leading ultimately to liver fibrosis and liver cancer. The occurrence of hepatocyte cell death-so far characterized as hepatocyte apoptosis-represents a fundamental step from benign steatosis toward progressive steatohepatitis. In contrast, the function of RIP3-dependent "necroptosis" in NASH and NASH-induced fibrosis is currently unknown.

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Chisari et al. challenge our central conclusion that the hepatitis B virus (HBV) persistent form, the covalently closed circular DNA (cccDNA), is degraded in a noncytotoxic and specific fashion in the nucleus of infected hepatocytes. Specificity of the assays used, exclusion of cell division or death, and activity of APOBEC3 deaminases in the nucleus, however, were addressed in the paper.

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Aims: Programmed necrosis (necroptosis) represents a newly identified mechanism of cell death combining features of both apoptosis and necrosis. Like apoptosis, necroptosis is tightly regulated by distinct signalling pathways. A key regulatory role in programmed necrosis has been attributed to interactions of the receptor-interacting protein kinases, RIP1 and RIP3.

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X-linked inhibitor of apoptosis protein (XIAP) has been identified as a potent regulator of innate immune responses, and loss-of-function mutations in XIAP cause the development of the X-linked lymphoproliferative syndrome type 2 (XLP-2) in humans. Using gene-targeted mice, we show that loss of XIAP or deletion of its RING domain lead to excessive cell death and IL-1β secretion from dendritic cells triggered by diverse Toll-like receptor stimuli. Aberrant IL-1β secretion is TNF dependent and requires RIP3 but is independent of cIAP1/cIAP2.

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Loss of intestinal epithelial cell (IEC) homeostasis and apoptosis negatively affect intestinal barrier function. Uncontrolled activation of the unfolded protein response (UPR) in IEC contributes to an impaired barrier and is implicated in the pathogenesis of inflammatory bowel diseases. However, the contribution of the UPR target gene C/EBP homologous protein (CHOP), an apoptosis-associated transcription factor, to inflammation-related disease susceptibility remains unclear.

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Background & Aims: In the liver, antigen-presenting cell populations such as Kupffer cells, liver dendritic cells, and liver sinusoidal endothelial cells (LSECs) participate through cross-presentation to CD8 T cells (CTLs) in hepatic immune-regulation and immune-surveillance. The participation of hepatic stellate cells (HSCs) in immune regulation is controversial. Here we studied HSC's contribution to antiviral CTL immunity.

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Due to its biological characteristics bovine herpesvirus 4 (BoHV-4) has been considered as an appropriate gene delivery vector. Its genomic clone, modified as a bacterial artificial chromosome (BAC), is better genetically manipulable and can be used as an efficient gene delivery and vaccine vector. Although a large amount of data have been accumulated in vitro on this specific aspect, the same cannot be asserted for the in vivo condition.

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Hepatitis B virus (HBV) integration in hepatocellular carcinoma (HCC) is a poorly understood event. In a recent Cancer Cell paper, Lau et al. (2014) describe a HBV-human fusion transcript (HBx-LINE1) that functions as a lncRNA, influences the epithelial-mesenchymal transition, and correlates with reduced patient survival and tumor formation in mice.

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Introduction: Natalizumab blocks α4-integrins and is a prototypic agent for a series of anti-inflammatory drugs that impair trafficking of immune cells into the CNS. However, modulation of the access of immune cells to the CNS is associated with impaired immune surveillance and detrimental viral infections of the CNS. Here, we explored the potency of cellular immune responses within the CNS to protect against viral encephalitis in mice with T cell conditional disruption of VLA-4 integrin (α4β1) expression.

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Current antiviral agents can control but not eliminate hepatitis B virus (HBV), because HBV establishes a stable nuclear covalently closed circular DNA (cccDNA). Interferon-α treatment can clear HBV but is limited by systemic side effects. We describe how interferon-α can induce specific degradation of the nuclear viral DNA without hepatotoxicity and propose lymphotoxin-β receptor activation as a therapeutic alternative.

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The pathogenic mechanisms of autoimmune pancreatitis (AIP), an increasingly recognized, immune-mediated form of chronic pancreatitis, have so far remained elusive. Treatment options for AIP are currently limited and disease relapse is frequent. Still, AIP can be characterized by specific clinical and histologic features.

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Unlabelled: Gene therapy has become an accepted concept for the treatment of a variety of different diseases. In contrast to preclinical models, subjects enrolled in clinical trials, including gene therapy, possess a history of infection with microbes that may influence its safety and efficacy. Especially, viruses that establish chronic infections in the liver, one of the main targets for in vivo gene therapy, raise important concerns.

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Article Synopsis
  • The study investigates the mechanisms behind brain metastasis in renal cell cancer (RCC), linking chemokine expression to increased brain metastasis risk.
  • Evidence shows that 15% of RCC patients had brain metastases at autopsy, with high expression of CXCR4 and increased CCR2 and CCL7 in brain lesions compared to primary tumors.
  • Findings suggest that CCR2 mediates monocyte recruitment, playing a significant role in the development of brain metastases in RCC patients.
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Immunoglobulin A (IgA) production at mucosal surfaces contributes to protection against pathogens and controls intestinal microbiota composition. However, mechanisms regulating IgA induction are not completely defined. We show that soluble lymphotoxin α (sLTα3) produced by RORγt(+) innate lymphoid cells (ILCs) controls T cell-dependent IgA induction in the lamina propria via regulation of T cell homing to the gut.

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Infections, microbe sampling and occasional leakage of commensal microbiota and their products across the intestinal epithelial cell layer represent a permanent challenge to the intestinal immune system. The production of reactive oxygen species by NADPH oxidase is thought to be a key element of defense. Patients suffering from chronic granulomatous disease are deficient in one of the subunits of NADPH oxidase.

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Microglia are brain macrophages and, as such, key immune-competent cells that can respond to environmental changes. Understanding the mechanisms of microglia-specific responses during pathologies is hence vital for reducing disease burden. The definition of microglial functions has so far been hampered by the lack of genetic in vivo approaches that allow discrimination of microglia from closely related peripheral macrophage populations in the body.

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For years, the term "apoptosis" was used synonymously with programmed cell death. However, it was recently discovered that receptor interacting protein 3 (RIP3)-dependent "necroptosis" represents an alternative programmed cell death pathway activated in many inflamed tissues. Here, we show in a genetic model of chronic hepatic inflammation that activation of RIP3 limits immune responses and compensatory proliferation of liver parenchymal cells (LPC) by inhibiting Caspase-8-dependent activation of Jun-(N)-terminal kinase in LPC and nonparenchymal liver cells.

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The tumor microenvironment consists of stromal cells and leukocytes that contribute to cancer progression. Cross-talk between tumor cells and their microenvironment is facilitated by a variety of soluble factors, including growth factors and cytokines such as chemokines. Due to a wide expression of chemokine receptors on cells in the tumor microenvironment, including tumor cells, chemokines affect various processes such as leukocyte recruitment, angiogenesis, tumor cell survival, tumor cell adhesion, proliferation, vascular permeability, immune suppression, invasion and metastasis.

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