Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread
Immunoglobulins are only moderately effective for the treatment of human cytomegalovirus (HCMV) infections, possibly due to ineffectiveness against cell-associated virus spread. To overcome this limitation, we aimed to identify individuals with exceptional antibodies in their plasma that can efficie...
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MDPI AG
2018-09-01
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| Series: | Viruses |
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| Online Access: | http://www.mdpi.com/1999-4915/10/9/500 |
| _version_ | 1819073599030427648 |
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| author | Jessica Julia Falk Martina Winkelmann Kerstin Laib Sampaio Caroline Paal Hubert Schrezenmeier Mira Alt Richard Stanton Adalbert Krawczyk Ramin Lotfi Christian Sinzger |
| author_facet | Jessica Julia Falk Martina Winkelmann Kerstin Laib Sampaio Caroline Paal Hubert Schrezenmeier Mira Alt Richard Stanton Adalbert Krawczyk Ramin Lotfi Christian Sinzger |
| author_sort | Jessica Julia Falk |
| collection | DOAJ |
| description | Immunoglobulins are only moderately effective for the treatment of human cytomegalovirus (HCMV) infections, possibly due to ineffectiveness against cell-associated virus spread. To overcome this limitation, we aimed to identify individuals with exceptional antibodies in their plasma that can efficiently block the cell-associated spread of HCMV. A Gaussia luciferase-secreting mutant of the cell-associated HCMV strain Merlin was generated, and luciferase activity evaluated as a readout for the extent of cell-associated focal spread. This reporter virus-based assay was then applied to screen plasma samples from 8400 HCMV-seropositive individuals for their inhibitory effect, including direct-acting antiviral drugs as positive controls. None of the plasmas reduced virus spread to the level of these controls. Even the top-scoring samples that partially reduced luciferase activity in the screening assay failed to inhibit focal growth when reevaluated with a more accurate, immunofluorescence-based assay. Selected sera with high neutralizing capacity against free viruses were analyzed separately, and none of them prevented the focal spread of three recent clinical HCMV isolates nor reduced the number of particles transmitted, as demonstrated with a fluorescent Merlin mutant. We concluded that donors with cell-to-cell-spread-inhibiting plasma are nonexistent or extremely rare, emphasizing cell-associated spread as a highly efficient immune escape mechanism of HCMV. |
| first_indexed | 2024-12-21T17:56:11Z |
| format | Article |
| id | doaj.art-654d9a670a554c3fb1009f949cb25e88 |
| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-12-21T17:56:11Z |
| publishDate | 2018-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Viruses |
| spelling | doaj.art-654d9a670a554c3fb1009f949cb25e882022-12-21T18:55:12ZengMDPI AGViruses1999-49152018-09-0110950010.3390/v10090500v10090500Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated SpreadJessica Julia Falk0Martina Winkelmann1Kerstin Laib Sampaio2Caroline Paal3Hubert Schrezenmeier4Mira Alt5Richard Stanton6Adalbert Krawczyk7Ramin Lotfi8Christian Sinzger9Institute for Virology, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Transfusion Medicine, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Virology, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Virology, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Transfusion Medicine, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Virology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, GermanyDivision of Infection and Immunity, Cardiff University School of Medicine, Cardiff CF14 4XN, UKInstitute for Virology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, GermanyInstitute for Transfusion Medicine, Ulm University Medical Center, 89081 Ulm, GermanyInstitute for Virology, Ulm University Medical Center, 89081 Ulm, GermanyImmunoglobulins are only moderately effective for the treatment of human cytomegalovirus (HCMV) infections, possibly due to ineffectiveness against cell-associated virus spread. To overcome this limitation, we aimed to identify individuals with exceptional antibodies in their plasma that can efficiently block the cell-associated spread of HCMV. A Gaussia luciferase-secreting mutant of the cell-associated HCMV strain Merlin was generated, and luciferase activity evaluated as a readout for the extent of cell-associated focal spread. This reporter virus-based assay was then applied to screen plasma samples from 8400 HCMV-seropositive individuals for their inhibitory effect, including direct-acting antiviral drugs as positive controls. None of the plasmas reduced virus spread to the level of these controls. Even the top-scoring samples that partially reduced luciferase activity in the screening assay failed to inhibit focal growth when reevaluated with a more accurate, immunofluorescence-based assay. Selected sera with high neutralizing capacity against free viruses were analyzed separately, and none of them prevented the focal spread of three recent clinical HCMV isolates nor reduced the number of particles transmitted, as demonstrated with a fluorescent Merlin mutant. We concluded that donors with cell-to-cell-spread-inhibiting plasma are nonexistent or extremely rare, emphasizing cell-associated spread as a highly efficient immune escape mechanism of HCMV.http://www.mdpi.com/1999-4915/10/9/500cytomegalovirusantibodiescell-associated spreadimmune evasion |
| spellingShingle | Jessica Julia Falk Martina Winkelmann Kerstin Laib Sampaio Caroline Paal Hubert Schrezenmeier Mira Alt Richard Stanton Adalbert Krawczyk Ramin Lotfi Christian Sinzger Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread Viruses cytomegalovirus antibodies cell-associated spread immune evasion |
| title | Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread |
| title_full | Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread |
| title_fullStr | Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread |
| title_full_unstemmed | Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread |
| title_short | Large-Scale Screening of HCMV-Seropositive Blood Donors Indicates that HCMV Effectively Escapes from Antibodies by Cell-Associated Spread |
| title_sort | large scale screening of hcmv seropositive blood donors indicates that hcmv effectively escapes from antibodies by cell associated spread |
| topic | cytomegalovirus antibodies cell-associated spread immune evasion |
| url | http://www.mdpi.com/1999-4915/10/9/500 |
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