Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD8 T cell killing of hepatitis C virus (HCV)-infected hepatocytes is thought to contribute to liver damage during chronic HCV infection, whereas the participation of HCV-nonspecific immune cells is unclear. To visualize the spatial relationship of HCV-specific CD8 T cells with parenchymal target cells, and to examine their local functional activity in relation to hepatocellular necrosis and fibrosis, we used HLA tetramers and confocal microscopy in biopsies from 23 HLA-A2 or HLA-B7 patients with chronic HCV infection. Intrahepatic tetramer+ (HCV-specific) CD8 T cells protected from hepatic necroinflammatory disease activity, independently of age, gender, viral load, and viral genotype. Indeed, tetramer+ cells were scattered in the liver within regions of weak fibrosis (low laminin expression) and low hepatocellular apoptosis (TUNEL method), and expressed IL-10 but not IFNgamma. By contrast, tetramer-negative CD8 T cells were associated with active necroinflammatory liver disease, colocalized with strong laminin expression and hepatocellular apoptosis, and expressed more frequently IFNgamma than IL-10. Overall, liver regions harboring HCV-specific CD8 T cells tended to be healthier than areas containing only inflammatory cells of undefined specificity. In conclusion, HCV-specific IL-10-producing CD8 T cells, although not cytotoxic and unable to control viral replication, can attenuate hepatocellular necrosis, liver fibrosis, and inflammation mediated by bystander T cells, and may thus represent antigen-induced regulatory CD8 T cells. Therapeutic modulation of the intrahepatic balance between specific and bystander CD8 T cells might be beneficial in patients with chronic hepatitis C.
 ...
PMID:Intrahepatic virus-specific IL-10-producing CD8 T cells prevent liver damage during chronic hepatitis C virus infection. 1713 91

The mechanisms of chronic HBV infection and immunopathogenesis are poorly understood due to a lack of a robust small animal model. Here we report the development of a humanized mouse model with both human immune system and human liver cells by reconstituting the immunodeficient A2/NSG (NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ mice with human HLA-A2 transgene) with human hematopoietic stem cells and liver progenitor cells (A2/NSG-hu HSC/Hep mice). The A2/NSG-hu HSC/Hep mouse supported HBV infection and approximately 75% of HBV infected mice established persistent infection for at least 4 months. We detected human immune responses, albeit impaired in the liver, chronic liver inflammation and liver fibrosis in infected animals. An HBV neutralizing antibody efficiently inhibited HBV infection and associated liver diseases in humanized mice. In addition, we found that the HBV mediated liver disease was associated with high level of infiltrated human macrophages with M2-like activation phenotype. Importantly, similar M2-like macrophage accumulation was confirmed in chronic hepatitis B patients with liver diseases. Furthermore, gene expression analysis showed that induction of M2-like macrophage in the liver is associated with accelerated liver fibrosis and necrosis in patients with acute HBV-induced liver failure. Lastly, we demonstrate that HBV promotes M2-like activation in both M1 and M2 macrophages in cell culture studies. Our study demonstrates that the A2/NSG-hu HSC/Hep mouse model is valuable in studying HBV infection, human immune responses and associated liver diseases. Furthermore, results from this study suggest a critical role for macrophage polarization in hepatitis B virus-induced immune impairment and liver pathology.
 ...
PMID:Hepatitis B virus infection and immunopathogenesis in a humanized mouse model: induction of human-specific liver fibrosis and M2-like macrophages. 2578 15