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Immunogenic profiling in mice of a HIV/AIDS vaccine candidate (MVA-B) expressing four HIV-1 antigens and potentiation by specific gene deletions.

García-Arriaza J, Nájera JL, Gómez CE, Sorzano CO, Esteban M - PLoS ONE (2010)

Bottom Line: Both vectors were capable of producing similar levels of antibodies against Env.These findings revealed that MVA-B and MVA-B DeltaA41L/DeltaB16R induced in mice robust, polyfunctional and durable T-cell responses to HIV-1 antigens, but the double deletion mutant showed enhanced magnitude and quality of HIV-1 adaptive and memory responses.Our observations are relevant in the immune evaluation of MVA-B and on improvements of MVA vectors as HIV-1 vaccines.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.

ABSTRACT

Background: The immune parameters of HIV/AIDS vaccine candidates that might be relevant in protection against HIV-1 infection are still undefined. The highly attenuated poxvirus strain MVA is one of the most promising vectors to be use as HIV-1 vaccine. We have previously described a recombinant MVA expressing HIV-1 Env, Gag, Pol and Nef antigens from clade B (referred as MVA-B), that induced HIV-1-specific immune responses in different animal models and gene signatures in human dendritic cells (DCs) with immunoregulatory function.

Methodology/principal findings: In an effort to characterize in more detail the immunogenic profile of MVA-B and to improve its immunogenicity we have generated a new vector lacking two genes (A41L and B16R), known to counteract host immune responses by blocking the action of CC-chemokines and of interleukin 1beta, respectively (referred as MVA-B DeltaA41L/DeltaB16R). A DNA prime/MVA boost immunization protocol was used to compare the adaptive and memory HIV-1 specific immune responses induced in mice by the parental MVA-B and by the double deletion mutant MVA-B DeltaA41L/DeltaB16R. Flow cytometry analysis revealed that both vectors triggered HIV-1-specific CD4(+) and CD8(+) T cells, with the CD8(+) T-cell compartment responsible for >91.9% of the total HIV-1 responses in both immunization groups. However, MVA-B DeltaA41L/DeltaB16R enhanced the magnitude and polyfunctionality of the HIV-1-specific CD4(+) and CD8(+) T-cell immune responses. HIV-1-specific CD4(+) T-cell responses were polyfunctional and preferentially Env-specific in both immunization groups. Significantly, while MVA-B induced preferentially Env-specific CD8(+) T-cell responses, MVA-B DeltaA41L/DeltaB16R induced more GPN-specific CD8(+) T-cell responses, with an enhanced polyfunctional pattern. Both vectors were capable of producing similar levels of antibodies against Env.

Conclusions/significance: These findings revealed that MVA-B and MVA-B DeltaA41L/DeltaB16R induced in mice robust, polyfunctional and durable T-cell responses to HIV-1 antigens, but the double deletion mutant showed enhanced magnitude and quality of HIV-1 adaptive and memory responses. Our observations are relevant in the immune evaluation of MVA-B and on improvements of MVA vectors as HIV-1 vaccines.

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Polyfunctionality of HIV-1-specific CD4+ and CD8+ T-cell memory responses induced by immunization with MVA-B and MVA-B ΔA41L/ΔB16R.Polyfunctionality of HIV-1-specific CD4+ and CD8+ T memory cells against HIV-1 peptide pools Env-pool, Gag-pool and GPN-pool, on the basis of IFN-γ and IL-2 secretion, and induced in mice 53 days after the last immunization with DNA-B/MVA-B or DNA-B/MVA-B ΔA41L/ΔB16R, and measured by ICS assay. (A) Functional composition of vaccine-induced CD4+ and CD8+ T memory cells specific for Env-pool+Gag pool+GPN-pool, based on the secretion of IFN-γ and/or IL-2. All the possible combinations of the responses are shown on the X axis, whereas the percentages of the functionally distinct cell populations are shown on the Y axis. Bars correspond to the fraction of different functionally distinct T-cell population within total CD4+ and CD8+ population. Standard deviations are shown. **, represent statistically significant differences between groups, p<0.005. Responses are grouped and color-coded on the basis of the number functions. The pie chart summarizes the data and each slice of the pie correspond to the fraction of CD4+ or CD8+T cells with a given number of functions within the total CD4+ or CD8+ T-cell memory populations. The size of the pie chart represents the magnitude of the specific HIV-1 memory immune response induced. A representative experiment out of two is shown. (B) Representative flow cytometry plots. The numbers indicate the percentage of memory CD4+ or CD8+ T cells expressing cytokine(s) IFN-γ and/or IL-2. The last sample (CD8+ T memory cells GPN-specific induced after immunization with DNA-φ/MVA-WT) was lost due to contamination, and the one represented derives from another independent experiment, to show lack of response.
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pone-0012395-g005: Polyfunctionality of HIV-1-specific CD4+ and CD8+ T-cell memory responses induced by immunization with MVA-B and MVA-B ΔA41L/ΔB16R.Polyfunctionality of HIV-1-specific CD4+ and CD8+ T memory cells against HIV-1 peptide pools Env-pool, Gag-pool and GPN-pool, on the basis of IFN-γ and IL-2 secretion, and induced in mice 53 days after the last immunization with DNA-B/MVA-B or DNA-B/MVA-B ΔA41L/ΔB16R, and measured by ICS assay. (A) Functional composition of vaccine-induced CD4+ and CD8+ T memory cells specific for Env-pool+Gag pool+GPN-pool, based on the secretion of IFN-γ and/or IL-2. All the possible combinations of the responses are shown on the X axis, whereas the percentages of the functionally distinct cell populations are shown on the Y axis. Bars correspond to the fraction of different functionally distinct T-cell population within total CD4+ and CD8+ population. Standard deviations are shown. **, represent statistically significant differences between groups, p<0.005. Responses are grouped and color-coded on the basis of the number functions. The pie chart summarizes the data and each slice of the pie correspond to the fraction of CD4+ or CD8+T cells with a given number of functions within the total CD4+ or CD8+ T-cell memory populations. The size of the pie chart represents the magnitude of the specific HIV-1 memory immune response induced. A representative experiment out of two is shown. (B) Representative flow cytometry plots. The numbers indicate the percentage of memory CD4+ or CD8+ T cells expressing cytokine(s) IFN-γ and/or IL-2. The last sample (CD8+ T memory cells GPN-specific induced after immunization with DNA-φ/MVA-WT) was lost due to contamination, and the one represented derives from another independent experiment, to show lack of response.

Mentions: To have a detailed assessment of the quality of the T-cell memory responses, we evaluated secretion of two cytokines (IFN-γ and IL-2) in HIV-1-specific CD4+ and CD8+ T cells (Figure 5). In general, both immunization groups induced HIV-1-specific CD4+ and CD8+ T memory cells with a similar polyfunctional pattern consisting of cells secreting two cytokines (range between 31.6% and 56.1%). However, DNA-B/MVA-B ΔA41L/ΔB16R induced a higher magnitude of polyfunctional CD4+ and CD8+ T memory cells (Figure 5A). The percentage of polyfunctional Env-specific CD8+ T memory cells were higher in DNA-B/MVA-B immunization group compared with DNA-B/MVA-B ΔA41L/ΔB16R (2.82% vs. 1.37% of double CD8+ T memory cells that secreted IFN-γ and IL-2, p<0.005). Gag-specific T memory cells were low, thus polyfunctionality was not significant. The percentage of polyfunctional GPN-specific CD8+ T memory cells were higher in DNA-B/MVA-B ΔA41L/ΔB16R immunization group compared with DNA-B/MVA-B (5.54% vs. 0.72% of double CD8+ T memory cells that secreted IFN-γ and IL-2, p<0.005) (Figure 5B).


Immunogenic profiling in mice of a HIV/AIDS vaccine candidate (MVA-B) expressing four HIV-1 antigens and potentiation by specific gene deletions.

García-Arriaza J, Nájera JL, Gómez CE, Sorzano CO, Esteban M - PLoS ONE (2010)

Polyfunctionality of HIV-1-specific CD4+ and CD8+ T-cell memory responses induced by immunization with MVA-B and MVA-B ΔA41L/ΔB16R.Polyfunctionality of HIV-1-specific CD4+ and CD8+ T memory cells against HIV-1 peptide pools Env-pool, Gag-pool and GPN-pool, on the basis of IFN-γ and IL-2 secretion, and induced in mice 53 days after the last immunization with DNA-B/MVA-B or DNA-B/MVA-B ΔA41L/ΔB16R, and measured by ICS assay. (A) Functional composition of vaccine-induced CD4+ and CD8+ T memory cells specific for Env-pool+Gag pool+GPN-pool, based on the secretion of IFN-γ and/or IL-2. All the possible combinations of the responses are shown on the X axis, whereas the percentages of the functionally distinct cell populations are shown on the Y axis. Bars correspond to the fraction of different functionally distinct T-cell population within total CD4+ and CD8+ population. Standard deviations are shown. **, represent statistically significant differences between groups, p<0.005. Responses are grouped and color-coded on the basis of the number functions. The pie chart summarizes the data and each slice of the pie correspond to the fraction of CD4+ or CD8+T cells with a given number of functions within the total CD4+ or CD8+ T-cell memory populations. The size of the pie chart represents the magnitude of the specific HIV-1 memory immune response induced. A representative experiment out of two is shown. (B) Representative flow cytometry plots. The numbers indicate the percentage of memory CD4+ or CD8+ T cells expressing cytokine(s) IFN-γ and/or IL-2. The last sample (CD8+ T memory cells GPN-specific induced after immunization with DNA-φ/MVA-WT) was lost due to contamination, and the one represented derives from another independent experiment, to show lack of response.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2927552&req=5

pone-0012395-g005: Polyfunctionality of HIV-1-specific CD4+ and CD8+ T-cell memory responses induced by immunization with MVA-B and MVA-B ΔA41L/ΔB16R.Polyfunctionality of HIV-1-specific CD4+ and CD8+ T memory cells against HIV-1 peptide pools Env-pool, Gag-pool and GPN-pool, on the basis of IFN-γ and IL-2 secretion, and induced in mice 53 days after the last immunization with DNA-B/MVA-B or DNA-B/MVA-B ΔA41L/ΔB16R, and measured by ICS assay. (A) Functional composition of vaccine-induced CD4+ and CD8+ T memory cells specific for Env-pool+Gag pool+GPN-pool, based on the secretion of IFN-γ and/or IL-2. All the possible combinations of the responses are shown on the X axis, whereas the percentages of the functionally distinct cell populations are shown on the Y axis. Bars correspond to the fraction of different functionally distinct T-cell population within total CD4+ and CD8+ population. Standard deviations are shown. **, represent statistically significant differences between groups, p<0.005. Responses are grouped and color-coded on the basis of the number functions. The pie chart summarizes the data and each slice of the pie correspond to the fraction of CD4+ or CD8+T cells with a given number of functions within the total CD4+ or CD8+ T-cell memory populations. The size of the pie chart represents the magnitude of the specific HIV-1 memory immune response induced. A representative experiment out of two is shown. (B) Representative flow cytometry plots. The numbers indicate the percentage of memory CD4+ or CD8+ T cells expressing cytokine(s) IFN-γ and/or IL-2. The last sample (CD8+ T memory cells GPN-specific induced after immunization with DNA-φ/MVA-WT) was lost due to contamination, and the one represented derives from another independent experiment, to show lack of response.
Mentions: To have a detailed assessment of the quality of the T-cell memory responses, we evaluated secretion of two cytokines (IFN-γ and IL-2) in HIV-1-specific CD4+ and CD8+ T cells (Figure 5). In general, both immunization groups induced HIV-1-specific CD4+ and CD8+ T memory cells with a similar polyfunctional pattern consisting of cells secreting two cytokines (range between 31.6% and 56.1%). However, DNA-B/MVA-B ΔA41L/ΔB16R induced a higher magnitude of polyfunctional CD4+ and CD8+ T memory cells (Figure 5A). The percentage of polyfunctional Env-specific CD8+ T memory cells were higher in DNA-B/MVA-B immunization group compared with DNA-B/MVA-B ΔA41L/ΔB16R (2.82% vs. 1.37% of double CD8+ T memory cells that secreted IFN-γ and IL-2, p<0.005). Gag-specific T memory cells were low, thus polyfunctionality was not significant. The percentage of polyfunctional GPN-specific CD8+ T memory cells were higher in DNA-B/MVA-B ΔA41L/ΔB16R immunization group compared with DNA-B/MVA-B (5.54% vs. 0.72% of double CD8+ T memory cells that secreted IFN-γ and IL-2, p<0.005) (Figure 5B).

Bottom Line: Both vectors were capable of producing similar levels of antibodies against Env.These findings revealed that MVA-B and MVA-B DeltaA41L/DeltaB16R induced in mice robust, polyfunctional and durable T-cell responses to HIV-1 antigens, but the double deletion mutant showed enhanced magnitude and quality of HIV-1 adaptive and memory responses.Our observations are relevant in the immune evaluation of MVA-B and on improvements of MVA vectors as HIV-1 vaccines.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.

ABSTRACT

Background: The immune parameters of HIV/AIDS vaccine candidates that might be relevant in protection against HIV-1 infection are still undefined. The highly attenuated poxvirus strain MVA is one of the most promising vectors to be use as HIV-1 vaccine. We have previously described a recombinant MVA expressing HIV-1 Env, Gag, Pol and Nef antigens from clade B (referred as MVA-B), that induced HIV-1-specific immune responses in different animal models and gene signatures in human dendritic cells (DCs) with immunoregulatory function.

Methodology/principal findings: In an effort to characterize in more detail the immunogenic profile of MVA-B and to improve its immunogenicity we have generated a new vector lacking two genes (A41L and B16R), known to counteract host immune responses by blocking the action of CC-chemokines and of interleukin 1beta, respectively (referred as MVA-B DeltaA41L/DeltaB16R). A DNA prime/MVA boost immunization protocol was used to compare the adaptive and memory HIV-1 specific immune responses induced in mice by the parental MVA-B and by the double deletion mutant MVA-B DeltaA41L/DeltaB16R. Flow cytometry analysis revealed that both vectors triggered HIV-1-specific CD4(+) and CD8(+) T cells, with the CD8(+) T-cell compartment responsible for >91.9% of the total HIV-1 responses in both immunization groups. However, MVA-B DeltaA41L/DeltaB16R enhanced the magnitude and polyfunctionality of the HIV-1-specific CD4(+) and CD8(+) T-cell immune responses. HIV-1-specific CD4(+) T-cell responses were polyfunctional and preferentially Env-specific in both immunization groups. Significantly, while MVA-B induced preferentially Env-specific CD8(+) T-cell responses, MVA-B DeltaA41L/DeltaB16R induced more GPN-specific CD8(+) T-cell responses, with an enhanced polyfunctional pattern. Both vectors were capable of producing similar levels of antibodies against Env.

Conclusions/significance: These findings revealed that MVA-B and MVA-B DeltaA41L/DeltaB16R induced in mice robust, polyfunctional and durable T-cell responses to HIV-1 antigens, but the double deletion mutant showed enhanced magnitude and quality of HIV-1 adaptive and memory responses. Our observations are relevant in the immune evaluation of MVA-B and on improvements of MVA vectors as HIV-1 vaccines.

Show MeSH
Related in: MedlinePlus