title: Internalization and propagation of the dengue virus in human hepatoma (HepG2) cells.
abstract: OBJECTIVE
  This study sought to undertake a comparative analysis of the internalization and propagation of all four dengue serotypes in a single cell line of human liver origin, HepG2.
  
  
  METHODS
  Virus production after infection was determined by the plaque assay technique. Internalization profiles were determined by incubating virus and cells on ice and then raising the temperature for various times. The contribution of extracellular matrix components to internalization was determined by pretreatment of cells with either trypsin or heparinase III.
  
  
  RESULTS
  HepG2 cells were able to support the propagation of all four serotypes with mature viruses being produced by 12 h for dengue serotype 4 and by 17-18 h for the remaining serotypes. Virus internalization showed a plateau for serotypes 1, 2 and 4 entry while serotype 3 showed a constant increase in internalization for up to 5 h. Pretreatment of HepG2 cells with heparinase III or trypsin both resulted in a reduction in viral production, with the smallest effect being noted for dengue serotype 3.
  
  
  CONCLUSIONS
  These results suggest that the interaction between the dengue virus and liver cells is a complex one that requires both protein and nonprotein elements, and has a significant serotype/strain element.
authors.affiliation: Molecular Pathology Laboratory, Institute of Molecular Biology and Genetics, Mahidol University, Nakorn Pathom, Thailand.
authors.forename: Chutima
authors.initials: C
authors.lastname: Thepparit
authors.forename: Waranyoo
authors.initials: W
authors.lastname: Phoolcharoen
authors.forename: Lukkana
authors.initials: L
authors.lastname: Suksanpaisan
authors.forename: Duncan R
authors.initials: DR
authors.lastname: Smith
mesh_terms: D045744:Cell Line, Tumor; D003716:Dengue Virus / Q000254:growth & development*; D022781:Hepatocytes / Q000821:virology*; D006801:Humans; D011133:Polysaccharide-Lyases / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism; D010948:Viral Plaque Assay; D014779:Virus Replication
chemical_list: D014357:Trypsin; D011133:Polysaccharide-Lyases; C021349:heparitinsulfate lyase