title: A two-step screening approach for the identification of blood donors with highly and broadly neutralizing capacities against human cytomegalovirus.
abstract: Hyperimmunoglobulins are frequently applied for prophylaxis and treatment of human cytomegalovirus (HCMV) infections but were only marginally effective in meta-analyses of clinical studies. This might be partially due to selection of donors rather for total anti-HCMV titers than for neutralizing capacities. To improve efficacy against HCMV infection, we aimed at developing a high-throughput screening method for identification of blood donors with highly and broadly neutralizing capacities.
  
  
  
  Using a Gaussia luciferase-expressing reporter virus, 1000 HCMV immunoglobulin (Ig)G-positive plasma samples with known anti-HCMV immunoglobulin titers were analyzed regarding their neutralization titers against fibroblast and endothelial cell infection. Based on these results, a high-throughput screening was designed. Highly neutralizing plasma samples were further tested 1) by an enzyme-linked immunosorbent assay-based neutralization assay regarding efficiency against different HCMV strains and 2) for their efficiency compared to commercially available hyperimmunoglobulins.
  
  
  
  Total anti-HCMV immunoglobulin titers did not correlate with neutralization. Mean neutralization capacities were 15-fold higher in endothelial cells compared to fibroblasts. All plasma samples neutralizing fibroblast infection were at least equally effective against infection of endothelial cells, providing the possibility to simplify our screening method by testing only fibroblasts as target cells with a plasma dilution of 1 in 400. Of the nine tested top HCMV neutralizers, four were broadly effective against different HCMV strains. All nine were significantly superior to hyperimmunoglobulins.
  
  
  
  Donors with highly and broadly neutralizing capacities can be identified by a two-step high-throughput screening approach. This may provide a basis for improved antibody-based treatment or prophylaxis of HCMV infections.
authors.affiliation: Institute for Virology, University Hospital Ulm, Ulm.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Falk
authors.affiliation: University Hospital Ulm.|Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, Ulm, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Winkelmann
authors.affiliation: Institute for Transfusion Medicine, University Hospital Ulm, Ulm.|University Hospital Ulm.|Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, Ulm, Germany.|German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Schrezenmeier
authors.affiliation: Institute for Virology, University Hospital Ulm, Ulm.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Stöhr
authors.affiliation: Institute for Virology, University Hospital Ulm, Ulm.
authors.forename: Christian
authors.initials: C
authors.lastname: Sinzger
authors.affiliation: Institute for Transfusion Medicine, University Hospital Ulm, Ulm.|University Hospital Ulm.|Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, Ulm, Germany.|German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen, Germany.
authors.forename: Ramin
authors.initials: R
authors.lastname: Lotfi
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood / Q000276:immunology / Q000494:pharmacology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology / Q000494:pharmacology; D001782:Blood Donors; D002461:Cell Line, Transformed; D003587:Cytomegalovirus / Q000276:immunology / Q000378:metabolism; D003586:Cytomegalovirus Infections / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism; D046148:Donor Selection / Q000379:methods*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology / Q000494:pharmacology; D008297:Male
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G