In vitro assay for neutralizing antibody to hepatitis C virus: evidence for broadly conserved neutralization epitopes.
Our understanding of the humoral immune response to hepatitis C virus (HCV) is limited because the virus can be studied only in humans and chimpanzees and because previously described neutralization assays have not been robust or simple to perform. Nevertheless, epidemiologic and laboratory studies suggested that neutralizing Ab to HCV might be important in preventing infection. We have recently described a neutralization assay based on the neutralization of pseudotyped murine retrovirus constructs bearing HCV envelope glycoproteins on their surface. We have applied the assay to well characterized clinical samples from HCV-infected patients and chimpanzees, confirmed the existence of neutralizing Ab to HCV, and validated most previously reported neutralizations of the virus. We did not find neutralizing anti-HCV in resolving infections but did find relatively high titers (>1:320) of such Ab in chronic infections. Neutralizing Ab was directed not only to epitope(s) in the hypervariable region of the E2 envelope protein but also to one or more epitopes elsewhere in the envelope of the virus. Neutralizing Ab was broadly reactive and could neutralize pseudotype particles bearing the envelope glycoproteins of two different subgenotypes (1a and 1b). The ability to assay neutralizing anti-HCV should permit an assessment of the prospects for successful Ab-mediated passive and active immunoprophylaxis against hepatitis C.
Bartosch
Birke
B
Laboratoire de Vectorologie Rétrovirale et Thérapie Génique, Institut National de la Santé et de la Recherche Médicale U412, IFR 128, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
Bukh
Jens
J
Meunier
Jean-Christophe
JC
Granier
Christelle
C
Engle
Ronald E
RE
Blackwelder
William C
WC
Emerson
Suzanne U
SU
Cosset
François-Loïc
FL
Purcell
Robert H
RH
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D017124:Conserved Sequence; D000939:Epitopes / Q000235:genetics; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000032:analysis* / Q000097:blood; D018936:Hepatitis C Antigens / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D002679:Pan troglodytes; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology
C087035:E1 protein, Hepatitis C virus; D000939:Epitopes; D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus