Antibody responses to a highly conserved peptide in HCV E2 protein correlate with chronicity or spontaneous clearance of HCV infection

Y Yong He (Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University) L Lilin Zhong (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) A Anthony Ruvindi DeSilva (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) K Kam Sang Kwok (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) L Lu Deng (Department of Animal Nutrition and Environmental Hygiene, College of Animal Science and Technology, Northwest A&F University) M Maria Luisa Virata (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) H Hailing Yan (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) D Dorothy Scott (Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration) M Marian Major H Harvey J. Alter (Department of Transfusion Medicine, Warren Grant Magnuson Clinical Center, National Institutes of Health) P Pei Zhang (Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology)

Abstract

Hepatitis C virus (HCV) infection frequently progresses to chronicity rather than spontaneous clearance, resulting in severe liver diseases including cirrhosis and hepatocellular carcinoma. The molecular mechanisms governing infection outcomes remain poorly understood. We identified Peptide A, a highly conserved epitope (residues 442 to 451) within HCV glycoprotein E2, and demonstrated that differential antibody binding patterns to this region correlate with distinct infection outcomes. This immunogenic, nonneutralizing epitope localizes to a structurally exposed region that shares residue 442 as a boundary with the previously characterized Epitope II (residues 430 to 442) and is positioned adjacent to variable region 2 (VR2, residues 460 to 485). Antibodies requiring both F442 and F447 residues within Peptide A for binding emerged early following infection and demonstrated strong correlation with chronic HCV progression. In contrast, antibodies binding exclusively to F447 were associated with spontaneous viral clearance and consistently co-occurred with Epitope II antibodies during later phases of infection. By establishing the relationship between these distinct antibody binding patterns and divergent infection outcomes, our findings elucidate potential HCV immune evasion mechanisms and may facilitate the development of predictive tools for determining chronic versus clearance outcomes early in infection, as well as inform rational vaccine design strategies.

Article Details

Volume / Issue Vol. 123, Issue 1
Published January 06, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (11)

Y

Yong He

Department of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University

L

Lilin Zhong

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

A

Anthony Ruvindi DeSilva

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

K

Kam Sang Kwok

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

L

Lu Deng

Department of Animal Nutrition and Environmental Hygiene, College of Animal Science and Technology, Northwest A&F University

M

Maria Luisa Virata

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

H

Hailing Yan

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

D

Dorothy Scott

Division of Plasma Derivatives, Office of Plasma Protein Therapeutics, Office of Therapeutic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration

M

Marian Major

H

Harvey J. Alter

Department of Transfusion Medicine, Warren Grant Magnuson Clinical Center, National Institutes of Health

P

Pei Zhang

Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology