title: A laboratory-adapted HCV JFH-1 strain is sensitive to neutralization and can gradually escape under the selection pressure of neutralizing human plasma.
abstract: Viral replication and neutralization of hepatitis C viruses (HCV) have been studied using the infectious molecular clone JFH-1. By passaging JFH-1 in hepatoma cells in the absence or presence of HCV neutralizing antibodies (nAbs), we investigated the molecular mechanisms of cell-culture adaptation and sensitivity to nAbs. The cell culture-adapted JFH-1 virus (JFH-1-CA) became more sensitive to nAbs than its parental virus. Sequence analysis revealed that the predominant viruses in the JFH-1-CA population carried two mutations in their envelopes (I414T and V293A). Plasma that could neutralize JFH-1-CA was found in 2 of 7 HCV-infected individuals who have cleared the virus in blood. Plasma 226233 with a higher 50% neutralization titer was used for in vitro selection of neutralization resistant viruses. Under the increasing selection pressure of plasma 226233, the neutralizing sensitivity of JFH-1-CA decreased gradually. Two mutations (T414I and P500S) in envelope were found in all but one sequenced clones in the viral population after eight rounds of selection. Interestingly, the cell-culture adapted mutation I414T reverted back to the wild-type residue (I414) under the selection pressure. By introducing mutations at positions 414 and 500 into the JFH-1 clone, we confirmed that the T414I mutation alone can confer neutralization resistance. The results of this current study suggest that nAbs are present in a subset of HCV-infected individuals who have cleared the virus in blood. Our data also provide the first evidence that, the E2 residue P500, located within a previously identified highly conserved polyclonal epitope, may be a target for neutralizing antibodies present in individual who have spontaneously resolved the HCV infection.
authors: Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
authors: Hongshuo
authors: H
authors: Song
authors: Furong
authors: F
authors: Ren
authors: Jin
authors: J
authors: Li
authors: Shuang
authors: S
authors: Shi
authors: Ling
authors: L
authors: Yan
authors: Feng
authors: F
authors: Gao
authors: Kui
authors: K
authors: Li
authors: Hui
authors: H
authors: Zhuang
mesh_terms: D000328:Adult; D057134:Antibodies, Neutralizing / Q000276:immunology*; D045744:Cell Line, Tumor; D016174:Hepacivirus / Q000235:genetics* / Q000254:growth & development / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000276:immunology*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D057131:Immune Evasion; D008297:Male; D020125:Mutation, Missense; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D014776:Virus Cultivation; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D018937:Hepatitis C Antibodies; D014759:Viral Envelope Proteins