title: Isolation of human monoclonal antibodies that potently neutralize human cytomegalovirus infection by targeting different epitopes on the gH/gL/UL128-131A complex.
abstract: Human cytomegalovirus (HCMV) is a widely circulating pathogen that causes severe disease in immunocompromised patients and infected fetuses. By immortalizing memory B cells from HCMV-immune donors, we isolated a panel of human monoclonal antibodies that neutralized at extremely low concentrations (90% inhibitory concentration [IC(90)] values ranging from 5 to 200 pM) HCMV infection of endothelial, epithelial, and myeloid cells. With the single exception of an antibody that bound to a conserved epitope in the UL128 gene product, all other antibodies bound to conformational epitopes that required expression of two or more proteins of the gH/gL/UL128-131A complex. Antibodies against gB, gH, or gM/gN were also isolated and, albeit less potent, were able to neutralize infection of both endothelial-epithelial cells and fibroblasts. This study describes unusually potent neutralizing antibodies against HCMV that might be used for passive immunotherapy and identifies, through the use of such antibodies, novel antigenic targets in HCMV for the design of immunogens capable of eliciting previously unknown neutralizing antibody responses.
authors.affiliation: Institute for Research in Biomedicine, Via Vincenzo Vela 6, CH-6500 Bellinzona, Switzerland. annalisa.macagno@irb.unisi.ch
authors.forename: Annalisa
authors.initials: A
authors.lastname: Macagno
authors.forename: Nadia L
authors.initials: NL
authors.lastname: Bernasconi
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Vanzetta
authors.forename: Erica
authors.initials: E
authors.lastname: Dander
authors.forename: Antonella
authors.initials: A
authors.lastname: Sarasini
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Revello
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gerna
authors.forename: Federica
authors.initials: F
authors.lastname: Sallusto
authors.forename: Antonio
authors.initials: A
authors.lastname: Lanzavecchia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000302:isolation & purification; D057134:Antibodies, Neutralizing / Q000276:immunology / Q000302:isolation & purification; D000914:Antibodies, Viral / Q000276:immunology / Q000302:isolation & purification; D002460:Cell Line; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000821:virology; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000821:virology; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000939:Epitopes; D008562:Membrane Glycoproteins; C532797:UL128 protein, human cytomegalovirus; D014759:Viral Envelope Proteins; C071440:glycoprotein H, Cytomegalovirus