Protein Synthesis by HepG2 Cells Infected with Influenza B Virus

Abstract

ABSTRACT. Reye's syndrome is an acute hepatopathy Inasmuch as extrapulmonary dissemination and viremia in and encephalopathy affecting children during the convales-influenza B virus infections are rare (4), it is difficult to postulate cent period of a viral infection, frequently influenza B. The a mechanism by which the hepatic abnormalities in Reye's role of influenza B in the pathogenesis of Reye's syndrome syndrome are induced. In rare instances, virus has been cultured is unknown. To investigate this relationship, an in vitro from the blood or hepatobiliary tissues of children dying from system was designed to examine the interaction of influenza Reye's syndrome, but there are no convincing data to suggest a B virus with a cell line of human hepatocytes (HepG2) direct inflammatory or immunologic component to the hepatic which retains many specific hepatic synthetic characteris-injury (5). tics. HepG2 was capable of supporting a productive infecUsing an animal model of Reye's syndrome described by Davis tion by influenza B, although greater virus inputs were et al. ( 6 ) we recently examined the clinical and histopathologic required than in fully permissive Madin-Darby canine kid-effects of influenza B, given intranasally or intravenously, on ney cells. Because of the recent association of Reye's juvenile BALB/c mice (7). Mice were observed up to 72 h after syndrome with aspirin use, the kinetics of influenza B inoculation. With the exception of hepatic steatosis, no clinical, growth were studied in the presence of acetylsalicylic acid biochemical, or histopathologic features of Reye's syndrome were (25 and 100 fig/ml) and were not found to be altered. demonstrable. The recovery of intact influenza B virus from the Protein synthesis by HepG2 cells was decreased by 80% liver in 25% of mice was unexpected. Inasmuch as other invesin influenza B-infected cells when compared to uninfected tigators have hypothesized a direct interaction of intact virus or controls. Acetylsalicyclic acid, 100 figlml, did not affect a viral gene product with the hepatocyte in Reye's syndrome (8, the rate of 35S-methionine incorporation by infected or 9), the recovery of virus from experimentally infected rats uninfected HepG2 cells. The rates of synthesis of specific prompted the design of an in vitro system for direct assessment proteins (albumin, transferrin, and apoprotein B) by of the interaction of influenza B virus with the hepatocyte. HepG2 cells were determined by immunoprecipitation of 35S-methionine labeled cell lysates. After 12 h of infection, synthesis of all three plasma proteins was decreased by 40-60%. These studies describe a useful system for delin- MATERIALS AND METHODS

Identification of Fibrosis-Relevant Proteins Using DIGE (Difference in Gel Electrophoresis) in Different Models of Hepatic Fibrosis

“…HepG2 cells were cultured as previously described [11]. In the state of 50 -60 % confluency the cells were infected by 2 10 8 pfu/ml of the adenoviral constructs.…”