Novel E2 Glycoprotein Tetramer Detects Hepatitis C Virus-Specific Memory B Cells

J Immunol. 2016 Dec 15;197(12):4848-4858. doi: 10.4049/jimmunol.1600763. Epub 2016 Nov 14.


Acute hepatitis C virus (HCV) infection culminates in viral persistence in the majority of cases. Abs that recognize the envelope glycoproteins E1 and E2 are generated during the late stages of acute infection, yet their contribution to spontaneous viral clearance remains controversial. Investigation of the humoral responses during acute HCV infection have been limited by the inability to directly identify and characterize HCV-specific B cells. In this study we describe the development of a novel tetramer of the E2 glycoprotein ectodomain (J6, genotype 2a strain), which allowed us to visualize E2-specific B cells longitudinally in the peripheral blood of HCV-infected individuals. HCV-specific class-switched memory B cells were detected in 3 out of 7 participants during late acute infection, with a mean frequency of 0.63% for positive samples (range 0.16-0.67%) and in 7 out of 7 participants with chronic infection with a mean frequency of 0.47% (range 0.20-0.78%). In a cross-sectional study, E2 tetramer positive population was detected in 28 out of 31 chronically infected individuals. Deep sequencing of the BCR from E2-specific class-switched memory B cells sorted from two independent participants revealed a focused repertoire suggestive of clonal selection. Tetramer-specific B cells exhibited skewed CDR3 length distribution and increased mutation frequency compared with naive B cells. This BCR profile is indicative of clonal expansion and affinity maturation. E2 tetramer allows for specific and sensitive ex vivo characterization of rare HCV-specific B cells in infected individuals, and will enable researchers to gain a better understanding of humoral immunity in HCV infection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / virology
  • Cross-Sectional Studies
  • Female
  • HEK293 Cells
  • Hepacivirus / immunology*
  • Hepatitis C / diagnosis*
  • Hepatitis C / immunology
  • Humans
  • Immunity, Humoral
  • Immunologic Memory
  • Immunologic Tests / methods*
  • Male
  • Protein Binding
  • Protein Engineering
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / immunology
  • Viral Envelope Proteins / metabolism*


  • Viral Envelope Proteins
  • glycoprotein E2, Hepatitis C virus