Recombinant human monoclonal antibodies to human cytomegalovirus glycoprotein B neutralize virus in a complement-dependent manner.
Human antibodies specific for HCMV are currently considered as potential anti-HCMV therapeutic agents. In this study, we used a combinatorial human antibody library to isolate and characterize complete human monoclonal antibodies that effectively neutralize HCMV in a complement-dependent manner. One hundred and six clones were isolated in two independent screens using HCMV virions and recombinant glycoprotein B, gB654, as antigens. All of the clones recognized the same molecule gB and were classified into 14 groups based on the amino acid sequence of the V(H) region. Seven representative clones from these 14 groups had a strong gB654 binding affinity by surface plasmon resonance (SPR). A pairwise binding competition analysis suggested that there were three groups based on differences in the gB recognition sites. Although Fab fragments of the seven groups showed strong affinity for gB, none of the Fab fragments neutralized HCMV infectivity in vitro. In contrast, complete human IgG(1) antibodies of at least three groups neutralized HCMV in a complement-dependent manner. These data suggest that potent therapeutic antibodies can be obtained from a human antibody library, including most of the functional antibodies that mediate humoral immunity to the selected pathogen.
Ohta
Akane
A
21st Century COE Research Center, Toyoake, Aichi, Japan.
Fujita
Ayano
A
Murayama
Tsugiya
T
Iba
Yoshitaka
Y
Kurosawa
Yoshikazu
Y
Yoshikawa
Tetsushi
T
Asano
Yoshizo
Y
D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D057134:Antibodies, Neutralizing / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000914:Antibodies, Viral / Q000276:immunology / Q000378:metabolism; D000956:Antigens, Viral / Q000378:metabolism; D001667:Binding, Competitive; D002460:Cell Line; D003165:Complement System Proteins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D019151:Peptide Library; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D020349:Surface Plasmon Resonance; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D019151:Peptide Library; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C040495:glycoprotein B, Simplexvirus; D003165:Complement System Proteins