Hepatitis C virus (HCV) E1 and E2 protein regions that specifically bind to HepG2 cells.
OBJECTIVE
Identify hepatitis C virus (HCV) sequences in E1 and E2 protein binding to HepG2.


METHODS
Synthetic 20-mer long, ten-residue overlapped peptides, from E1 and E2 proteins, were tested in HepG2 or Raji cell-binding assays. Affinity constants, binding site number per cell and Hill coefficients were determined by saturation assay for high activity binding peptides (HABPs). Receptors for HepG2 cell were determined by cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.


RESULTS
Twelve HABPs were found in HCV genotype 1a, allowing six hepatocyte-binding sequences (HBSs) to be defined: two peptide-binding regions in E1 HABPs 4913 (YQVRNSTGLYHVTNDCPNSS) and 4918 (MTPTVATRDGKLPATQLRRHY). Four hepatocyte-binding regions were defined in E2: region-I, peptide 4931 (ETHVTGGSAGHTVSGFVSLLY); region-II, 4937-4939 (HHKFNSSGCPERLASCRPLTDFDQGWGPISYANGSGPDQR); region-III, 4943-4945 (PVYCFTPSPVVVGTTDRSGAPTYSWGENDTDVFVLNNTR) and region-IV, 4949-4952 (CGAPPCVIGGAGNNTLHCPTDCFRKHPDATYSRCGSGPWITPRCLVDYPY). The underlined sequences are most relevant in the binding process. HABPs 4913 and 4938 also bind to CD81 positive Raji cells. Region-II 4938 HABPs bind to 50 and 60kDa HepG2 cell membrane surface proteins.


CONCLUSIONS
Six HVRs to the HepG2 were identified. Some HABPs have been previously found to be antigenic and immunogenic. HABPs, 4918 (from E1), 4938, 4949, 4950, 4951 and 4952 (from E2) have not been previously recognised. These HABPs could be relevant to HCV invasion of hepatocytes.
Garcia
Javier Eduardo
JE
Fundación Instituto de Inmunologia de Colombia, Universidad Nacional de Colombia, Avda. Calle 26 No. 51-60 Bogota, Colombia. javgar22@hotmail.com
Puentes
Alvaro
A
Súarez
Jorge
J
López
Ramses
R
Vera
Ricardo
R
Rodríguez
Luis Eduardo
LE
Ocampo
Marisol
M
Curtidor
Hernando
H
Guzman
Fanny
F
Urquiza
Mauricio
M
Patarroyo
Manuel Elkin
ME
D000595:Amino Acid Sequence; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000821:virology*; D006801:Humans; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000235:genetics; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000821:virology; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
C087035:E1 protein, Hepatitis C virus; C400562:HVR1 protein, Hepatitis C virus; D007457:Iodine Radioisotopes; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C091015:glycoprotein E2, Hepatitis C virus