title: Structural proteins of Hepatitis C virus induce interleukin 8 production and apoptosis in human endothelial cells.
abstract: Hepatitis C virus (HCV) infection is associated with inflammation of liver endothelium, which contributes to the pathogenesis of chronic hepatitis. The mechanism of this endothelitis is not understood, since the virus does not appear to infect endothelial cells productively. Here, an 'innocent bystander' mechanism related to HCV proteins was hypothesized and it was investigated whether the binding of HCV particles to human endothelium induced functional changes in the cells. Exposure of human umbilical vein endothelial cells (HUVECs) to HCV-like particles (HCV-LPs) resulted in increased interleukin 8 (IL8) production and induction of apoptosis. The IL8 supernatants collected after stimulation of HUVECs with HCV-LPs, BV-GUS (control baculovirus containing beta-glucuronidase) and appropriate controls were used to assay the transendothelial migration of neutrophils. This assay confirmed that HCV-LP-induced IL8 was functionally active. Using specific NF-kappaB inhibitors, it was also shown that HCV-LP-induced NF-kappaB activity mediated IL8 production in HUVECs. Apoptosis appeared to be mediated by the Fas/Fas-L pathway, as neutralizing antibodies for Fas and Fas-L significantly protected HUVECs against HCV-LP-induced apoptosis. Treatment of HUVECs with HCV-LPs also enhanced cellular Fas-L expression and augmented caspase-3 activation. This was confirmed by using a specific caspase-3 inhibitor, Z-Asp-Glu-Val-Asp-fluoromethyl ketone. As shown by blocking of specific chemokine receptors for IL8 on HUVECs, the induction of IL8 did not appear to contribute to HCV-LP-induced apoptosis. These results suggest that HCV proteins can trigger the release of inflammatory chemokines such as IL8 and cause endothelial apoptosis, thereby facilitating endothelitis.
authors.affiliation: Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 4 Blackfan Circle, 3rd Floor, Boston, MA 02115, USA.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Balasubramanian
authors.affiliation: Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 4 Blackfan Circle, 3rd Floor, Boston, MA 02115, USA.
authors.forename: Neru
authors.initials: N
authors.lastname: Munshi
authors.affiliation: Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, 4 Blackfan Circle, 3rd Floor, Boston, MA 02115, USA.
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Koziel
authors.affiliation: Liver Diseases Section, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Zongyi
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Liver Diseases Section, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: T Jake
authors.initials: TJ
authors.lastname: Liang
authors.affiliation: Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 4 Blackfan Circle, 3rd Floor, Boston, MA 02115, USA.
authors.forename: Jerome E
authors.initials: JE
authors.lastname: Groopman
authors.affiliation: Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 4 Blackfan Circle, 3rd Floor, Boston, MA 02115, USA.
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Ganju
mesh_terms: D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000032:analysis; D002464:Cell Migration Inhibition; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism / Q000821:virology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism / Q000821:virology; D053222:Fas Ligand Protein; D016174:Hepacivirus / Q000472:pathogenicity*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000037:antagonists & inhibitors; D016328:NF-kappa B / Q000032:analysis; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors / Q000032:analysis; D015678:Viral Structural Proteins / Q000502:physiology*; D022701:Virosomes; D019014:fas Receptor
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors; D015678:Viral Structural Proteins; D022701:Virosomes; D019014:fas Receptor; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases