Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity
Modified vaccinia virus Ankara (MVA) is a highly attenuated strain of vaccinia virus, which has been used as a recombinant vaccine vector in many vaccine development programmes. The loss of many immunosuppressive and host-range genes resulted in a safe and immunogenic vaccine vector. However it stil...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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Public Library of Science
2015
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| _version_ | 1797078370532458496 |
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| author | Alharbi, N Spencer, A Hill, A Gilbert, S |
| author_facet | Alharbi, N Spencer, A Hill, A Gilbert, S |
| author_sort | Alharbi, N |
| collection | OXFORD |
| description | Modified vaccinia virus Ankara (MVA) is a highly attenuated strain of vaccinia virus, which has been used as a recombinant vaccine vector in many vaccine development programmes. The loss of many immunosuppressive and host-range genes resulted in a safe and immunogenic vaccine vector. However it still retains some immunomodulatory genes that may reduce MVA immunogenicity. Earlier reports demonstrated that the deletion of the A41L, B15R, C6L, or C12L open reading frames (ORFs) enhanced cellular immune responses in recombinant MVA (rMVA) by up to 2-fold. However, previously, we showed that deletion of the C12L, A44L, A46R, B7R, or B15R ORFs from rMVA, using MVA-BAC recombineering technology, did not enhance rMVA immunogenicity at either peak or memory cellular immune responses. Here, we extend our previous study to examine the effect of deleting clusters of genes on rMVA cellular immunogenicity. Two clusters of fifteen genes were deleted in one rMVA mutant that encodes either the 85A antigen of Mycobacterium tuberculosis or an immunodominant H2-Kd-restricted murine malaria epitope (pb9). The deletion mutants were tested in prime only or prime and boost vaccination regimens. The responses showed no improved peak or memory CD8+ T cell frequencies. Our results suggest that the reported small increases in MVA deletion mutants could not be replicated with different antigens, or epitopes. Therefore, the gene deletion strategy may not be taken as a generic approach for improving the immunogenicity of MVA-based vaccines, and should be carefully assessed for every individual recombinant antigen. |
| first_indexed | 2024-03-07T00:30:59Z |
| format | Journal article |
| id | oxford-uuid:7fcb1293-b491-4e02-914d-6fe947ef92b6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:30:59Z |
| publishDate | 2015 |
| publisher | Public Library of Science |
| record_format | dspace |
| spelling | oxford-uuid:7fcb1293-b491-4e02-914d-6fe947ef92b62022-03-26T21:19:10ZDeletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7fcb1293-b491-4e02-914d-6fe947ef92b6EnglishSymplectic Elements at OxfordPublic Library of Science2015Alharbi, NSpencer, AHill, AGilbert, SModified vaccinia virus Ankara (MVA) is a highly attenuated strain of vaccinia virus, which has been used as a recombinant vaccine vector in many vaccine development programmes. The loss of many immunosuppressive and host-range genes resulted in a safe and immunogenic vaccine vector. However it still retains some immunomodulatory genes that may reduce MVA immunogenicity. Earlier reports demonstrated that the deletion of the A41L, B15R, C6L, or C12L open reading frames (ORFs) enhanced cellular immune responses in recombinant MVA (rMVA) by up to 2-fold. However, previously, we showed that deletion of the C12L, A44L, A46R, B7R, or B15R ORFs from rMVA, using MVA-BAC recombineering technology, did not enhance rMVA immunogenicity at either peak or memory cellular immune responses. Here, we extend our previous study to examine the effect of deleting clusters of genes on rMVA cellular immunogenicity. Two clusters of fifteen genes were deleted in one rMVA mutant that encodes either the 85A antigen of Mycobacterium tuberculosis or an immunodominant H2-Kd-restricted murine malaria epitope (pb9). The deletion mutants were tested in prime only or prime and boost vaccination regimens. The responses showed no improved peak or memory CD8+ T cell frequencies. Our results suggest that the reported small increases in MVA deletion mutants could not be replicated with different antigens, or epitopes. Therefore, the gene deletion strategy may not be taken as a generic approach for improving the immunogenicity of MVA-based vaccines, and should be carefully assessed for every individual recombinant antigen. |
| spellingShingle | Alharbi, N Spencer, A Hill, A Gilbert, S Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title | Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title_full | Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title_fullStr | Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title_full_unstemmed | Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title_short | Deletion of fifteen open reading frames from modified vaccinia virus Ankara fails to improve immunogenicity |
| title_sort | deletion of fifteen open reading frames from modified vaccinia virus ankara fails to improve immunogenicity |
| work_keys_str_mv | AT alharbin deletionoffifteenopenreadingframesfrommodifiedvacciniavirusankarafailstoimproveimmunogenicity AT spencera deletionoffifteenopenreadingframesfrommodifiedvacciniavirusankarafailstoimproveimmunogenicity AT hilla deletionoffifteenopenreadingframesfrommodifiedvacciniavirusankarafailstoimproveimmunogenicity AT gilberts deletionoffifteenopenreadingframesfrommodifiedvacciniavirusankarafailstoimproveimmunogenicity |