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Multiple epitopes of hepatitis B virus surface antigen targeted by human plasma-derived immunoglobulins coincide with clinically observed escape mutations.

Sreya TarafdarMaria Luisa VirataHailing YanLilin ZhongLu DengYanqun XuYong HeEvi StrublePei Zhang
Published in: Journal of medical virology (2021)
Hepatitis B immune globulin (HBIG) is a human plasma-derived immunoglobulin G concentrate that contains a high titer of neutralizing antibodies (anti-HBs) to the hepatitis B virus (HBV) surface antigen (HBsAg). HBIG is known to be highly effective in treating HBV infections, however, a more systematic characterization of the antibody binding sites on HBsAg and their correlation with emerging "escape" mutations in HBsAg was lacking. By using anti-HBs antibodies from HBIG lots to screen random peptide phage display libraries, we identified five clusters of peptides that corresponded to five distinct anti-HBs binding sites on the HBsAg. Three sites, Site II (C121-C124), Site III (M133-P135), and Site IV (T140-G145), were mapped within the "a" determinant, while the two other sites, Site I (Q101-M103) and Site V (I152-S154), were outside the "a" determinant. We then tested in binding assays HBsAg peptides containing clinically relevant mutations previously reported within these sites, such as Y134S, P142S, and G145R, and observed a significant reduction in anti-HBs binding activity to the mutated sites, suggesting a mechanism the virus may use to avoid HBIG-mediated neutralization. The current HBIG treatment could be improved by supplementing it with site-specific neutralizing monoclonal antibodies that target these mutations for control of HBV infections.
Keyphrases
  • hepatitis b virus
  • liver failure
  • high throughput
  • dengue virus
  • pseudomonas aeruginosa
  • binding protein
  • cystic fibrosis
  • cancer therapy
  • aedes aegypti