The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen

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dc.contributor.authorChapman, Rosamunden_ZA
dc.contributor.authorBourn, William Ren_ZA
dc.contributor.authorShephard, Eniden_ZA
dc.contributor.authorStutz, Helenen_ZA
dc.contributor.authorDouglass, Nicolaen_ZA
dc.contributor.authorMgwebi, Thandien_ZA
dc.contributor.authorMeyers, Annen_ZA
dc.contributor.authorChin'ombe, Nyashaen_ZA
dc.contributor.authorWilliamson, Anna-Liseen_ZA
dc.date.accessioned2016-01-11T06:48:37Z
dc.date.available2016-01-11T06:48:37Z
dc.date.issued2014en_ZA
dc.description.abstractNumerous features make Mycobacterium bovis BCG an attractive vaccine vector for HIV. It has a good safety profile, it elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable. Despite these advantages it is often difficult to express viral antigens in BCG, which results in genetic instability and low immunogenicity. The aim of this study was to generate stable recombinant BCG (rBCG) that express high levels of HIV antigens, by modification of the HIV genes. A directed evolution process was applied to recombinant mycobacteria that expressed HIV-1 Gag fused to the green fluorescent protein (GFP). Higher growth rates and increased GFP expression were selected for. Through this process a modified Gag antigen was selected. Recombinant BCG that expressed the modified Gag (BCG[pWB106] and BCG[pWB206]) were more stable, produced higher levels of antigen and grew faster than those that expressed the unmodified Gag (BCG[pWB105]). The recombinant BCG that expressed the modified HIV-1 Gag induced 2 to 3 fold higher levels of Gag-specific CD4 T cells than those expressing the unmodified Gag (BCG[pWB105]). Mice primed with 10 7 CFU BCG[pWB206] and then boosted with MVA-Gag developed Gag-specific CD8 T cells with a frequency of 1343±17 SFU/10 6 splenocytes, 16 fold greater than the response induced with MVA-Gag alone. Levels of Gag-specific CD4 T cells were approximately 5 fold higher in mice primed with BCG[pWB206] and boosted with MVA-Gag than in those receiving the MVA-Gag boost alone. In addition mice vaccinated with BCG[pWB206] were protected from a surrogate vaccinia virus challenge.en_ZA
dc.identifier.apacitationChapman, R., Bourn, W. R., Shephard, E., Stutz, H., Douglass, N., Mgwebi, T., ... Williamson, A. (2014). The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen. <i>PLoS One</i>, http://hdl.handle.net/11427/16227en_ZA
dc.identifier.chicagocitationChapman, Rosamund, William R Bourn, Enid Shephard, Helen Stutz, Nicola Douglass, Thandi Mgwebi, Ann Meyers, Nyasha Chin'ombe, and Anna-Lise Williamson "The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen." <i>PLoS One</i> (2014) http://hdl.handle.net/11427/16227en_ZA
dc.identifier.citationChapman, R., Bourn, W. R., Shephard, E., Stutz, H., Douglass, N., Mgwebi, T., ... & Williamson, A. L. (2013). The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen. PloS one, 9(7), e103314. doi:10.1371/journal.pone.0103314en_ZA
dc.identifier.ris TY - Journal Article AU - Chapman, Rosamund AU - Bourn, William R AU - Shephard, Enid AU - Stutz, Helen AU - Douglass, Nicola AU - Mgwebi, Thandi AU - Meyers, Ann AU - Chin'ombe, Nyasha AU - Williamson, Anna-Lise AB - Numerous features make Mycobacterium bovis BCG an attractive vaccine vector for HIV. It has a good safety profile, it elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable. Despite these advantages it is often difficult to express viral antigens in BCG, which results in genetic instability and low immunogenicity. The aim of this study was to generate stable recombinant BCG (rBCG) that express high levels of HIV antigens, by modification of the HIV genes. A directed evolution process was applied to recombinant mycobacteria that expressed HIV-1 Gag fused to the green fluorescent protein (GFP). Higher growth rates and increased GFP expression were selected for. Through this process a modified Gag antigen was selected. Recombinant BCG that expressed the modified Gag (BCG[pWB106] and BCG[pWB206]) were more stable, produced higher levels of antigen and grew faster than those that expressed the unmodified Gag (BCG[pWB105]). The recombinant BCG that expressed the modified HIV-1 Gag induced 2 to 3 fold higher levels of Gag-specific CD4 T cells than those expressing the unmodified Gag (BCG[pWB105]). Mice primed with 10 7 CFU BCG[pWB206] and then boosted with MVA-Gag developed Gag-specific CD8 T cells with a frequency of 1343±17 SFU/10 6 splenocytes, 16 fold greater than the response induced with MVA-Gag alone. Levels of Gag-specific CD4 T cells were approximately 5 fold higher in mice primed with BCG[pWB206] and boosted with MVA-Gag than in those receiving the MVA-Gag boost alone. In addition mice vaccinated with BCG[pWB206] were protected from a surrogate vaccinia virus challenge. DA - 2014 DB - OpenUCT DO - 10.1371/journal.pone.0103314 DP - University of Cape Town J1 - PLoS One LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 T1 - The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen TI - The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen UR - http://hdl.handle.net/11427/16227 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/16227
dc.identifier.urihttp://dx.doi.org/10.1371/journal.pone.0103314
dc.identifier.vancouvercitationChapman R, Bourn WR, Shephard E, Stutz H, Douglass N, Mgwebi T, et al. The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen. PLoS One. 2014; http://hdl.handle.net/11427/16227.en_ZA
dc.language.isoengen_ZA
dc.publisherPublic Library of Scienceen_ZA
dc.publisher.departmentDivision of Virologyen_ZA
dc.publisher.facultyFaculty of Health Sciencesen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en_ZA
dc.rights.holder© 2014 Chapman et alen_ZA
dc.rights.urihttp://creativecommons.org/licenses/by/4.0en_ZA
dc.sourcePLoS Oneen_ZA
dc.source.urihttp://journals.plos.org/plosoneen_ZA
dc.subject.otherCytotoxic T cellsen_ZA
dc.subject.otherRecombinant proteinsen_ZA
dc.subject.otherT cellsen_ZA
dc.subject.otherPlasmid constructionen_ZA
dc.subject.otherImmune responseen_ZA
dc.subject.otherCloningen_ZA
dc.subject.otherVaccinesen_ZA
dc.subject.otherRecombinant vaccinesen_ZA
dc.titleThe use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigenen_ZA
dc.typeJournal Articleen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceArticleen_ZA
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