title: Neutralizing activities of caprine antibodies towards conserved regions of the HCV envelope glycoprotein E2.
abstract: Anti HCV vaccine is not currently available and the present antiviral therapies fail to cure approximately half of the treated HCV patients. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 and test their neutralizing activities in a step towards developing therapeutic and/or prophylactic immunogens against HCV infection. Antibodies were generated by vaccination of goats with synthetic peptides derived from HCV E2. Viral neutralizing capacity of the generated anti E2 antibodies was tested using in vitro assays. Goats immunized with E2 synthetic peptides termed p412 [a.a 412-419], p430 [a.a 430-447] and p517 [a.a 517-531] generated high titers of antibody responses 2 to 4.5 fold higher than comparable titers of antibodies to the same epitopes in chronic HCV patients. In post infection experiments of native HCV into cultured Huh7.5 cells anti p412 and anti p 517 were proven to be neutralizing to HCV genotype 4a from patients' sera (87.5% and 75% respectively). On the contrary anti p430 exhibited weak viral neutralization capacity on the same samples (31.25%). Furthermore Ab mixes containing anti p430 exhibited reduced viral neutralization properties. From these experiments one could predict that neutralization by Abs towards different E2-epitopes varies considerably and success in the enrichment of neutralization epitope-specific antibodies may be accompanied by favorable results in combating HCV infection. Also, E2 conserved peptides p517 and p412 represent potential components of a candidate peptide vaccine against HCV infection.
authors.affiliation: Department of Microbial Biotechnology, National Research Center, Giza, Egypt.
authors.forename: Yasmine S
authors.initials: YS
authors.lastname: El Abd
authors.forename: Ashraf A
authors.initials: AA
authors.lastname: Tabll
authors.forename: Noha G Bader
authors.initials: NG
authors.lastname: El Din
authors.forename: Alaa El-Dien S
authors.initials: Ael-D
authors.lastname: Hosny
authors.forename: Rehab I
authors.initials: RI
authors.lastname: Moustafa
authors.forename: Reem
authors.initials: R
authors.lastname: El-Shenawy
authors.forename: Khaled
authors.initials: K
authors.lastname: Atef
authors.forename: Mostafa K
authors.initials: MK
authors.lastname: El-Awady
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D057134:Antibodies, Neutralizing / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D000918:Antibody Specificity; D000940:Antigenic Variation; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000276:immunology / Q000473:pathology / Q000821:virology; D045744:Cell Line, Tumor; D017124:Conserved Sequence / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D006041:Goats / Q000276:immunology* / Q000821:virology; D016174:Hepacivirus / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D006526:Hepatitis C / Q000188:drug therapy / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D018937:Hepatitis C Antibodies / Q000276:immunology* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D009500:Neutralization Tests; D010455:Peptides / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology; D014611:Vaccination; D022223:Vaccines, Subunit / Q000737:chemistry / Q000276:immunology; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000737:chemistry / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000939:Epitopes; C400562:HVR1 protein, Hepatitis C virus; D018937:Hepatitis C Antibodies; D010455:Peptides; D022223:Vaccines, Subunit; D014759:Viral Envelope Proteins; D014761:Viral Hepatitis Vaccines; D014764:Viral Proteins; C091015:glycoprotein E2, Hepatitis C virus