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Improving the MVA vaccine potential by deleting the viral gene coding for the IL-18 binding protein.
- Source :
-
PloS one [PLoS One] 2012; Vol. 7 (2), pp. e32220. Date of Electronic Publication: 2012 Feb 22. - Publication Year :
- 2012
-
Abstract
- Background: Modified Vaccinia Ankara (MVA) is an attenuated strain of Vaccinia virus (VACV) currently employed in many clinical trials against HIV/AIDS and other diseases. MVA still retains genes involved in host immune response evasion, enabling its optimization by removing some of them. The aim of this study was to evaluate cellular immune responses (CIR) induced by an IL-18 binding protein gene (C12L) deleted vector (MVAΔC12L).<br />Methodology/principal Findings: BALB/c and C57BL/6 mice were immunized with different doses of MVAΔC12L or MVA wild type (MVAwt), then CIR to VACV epitopes in immunogenic proteins were evaluated in spleen and draining lymph nodes at acute and memory phases (7 and 40 days post-immunization respectively). Compared with parental MVAwt, MVAΔC12L immunization induced a significant increase of two to three-fold in CD8(+) and CD4(+) T-cell responses to different VACV epitopes, with increased percentage of anti-VACV cytotoxic CD8(+) T-cells (CD107a/b(+)) during the acute phase of the response. Importantly, the immunogenicity enhancement was also observed after MVAΔC12L inoculation with different viral doses and by distinct routes (systemic and mucosal). Potentiation of MVA's CIR was also observed during the memory phase, in correlation with a higher protection against an intranasal challenge with VACV WR. Of note, we could also show a significant increase in the CIR against HIV antigens such as Env, Gag, Pol and Nef from different subtypes expressed from two recombinants of MVAΔC12L during heterologous DNA prime/MVA boost vaccination regimens.<br />Conclusions/significance: This study demonstrates the relevance of IL-18 bp contribution in the immune response evasion during MVA infection. Our findings clearly show that the deletion of the viral IL-18 bp gene is an effective approach to increase MVA vaccine efficacy, as immunogenicity improvements were observed against vector antigens and more importantly to HIV antigens.
- Subjects :
- AIDS Vaccines chemistry
Animals
CD8-Positive T-Lymphocytes metabolism
Chickens
Female
Gene Deletion
Genetic Vectors
Immunologic Memory
Intercellular Signaling Peptides and Proteins genetics
Interferon-gamma metabolism
Interleukin-18
Interleukin-2 metabolism
Lymph Nodes pathology
Mice
Mice, Inbred BALB C
Mice, Inbred C57BL
Spleen metabolism
AIDS Vaccines therapeutic use
Intercellular Signaling Peptides and Proteins chemistry
Vaccinia virus metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 7
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 22384183
- Full Text :
- https://doi.org/10.1371/journal.pone.0032220