A divalent antibody format is required for neutralization of human cytomegalovirus via antigenic domain 2 on glycoprotein B.
Glycoprotein B (gB) of human cytomegalovirus (HCMV) is the dominating protein in the envelope of this virus and gives rise to virus-neutralizing antibodies in most infected individuals. We have previously isolated a neutralizing human antibody specific for antigenic domain 2 (AD-2) on gB, a poorly immunogenic epitope, which nevertheless is capable of eliciting potent neutralizing antibodies. In order to define parameters important for the neutralization of HCMV via gB, we have investigated the virus-neutralizing capacity and the kinetics of the interaction with AD-2 of the monomeric and dimeric forms of a single chain variable fragment (scFv) corresponding to this antibody. We demonstrate here that neutralization of HCMV via AD-2 on gB can be mediated by dimeric scFv, while monomeric fragments cannot mediate neutralization of the virus, despite a slow dissociation from the intact glycoprotein. This finding is discussed in the context of possible mechanisms for antibody-mediated virus neutralization.
Lantto
Johan
J
Department of Immunotechnology, Lund University, PO Box 7031, S-220 07 Lund, Sweden1.
Fletcher
Jean M
JM
Department of Immunology, Royal Free and University College Medical School, Royal Free Campus, London NW3 2PF, UK2.
Ohlin
Mats
M
Department of Immunotechnology, Lund University, PO Box 7031, S-220 07 Lund, Sweden1.
D000595:Amino Acid Sequence; D000914:Antibodies, Viral / Q000737:chemistry* / Q000276:immunology; D000956:Antigens, Viral / Q000737:chemistry / Q000276:immunology*; D002460:Cell Line; D003587:Cytomegalovirus / Q000737:chemistry / Q000276:immunology*; D019281:Dimerization; D005455:Fluorescent Antibody Technique; D006801:Humans; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000276:immunology*; D007700:Kinetics; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D007128:Immunoglobulin Fragments; D010455:Peptides; D014759:Viral Envelope Proteins; C040495:glycoprotein B, Simplexvirus