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Prime-boost vaccination using chemokine-fused gp120 DNA and HIV envelope peptides activates both immediate and long-term memory cellular responses in rhesus macaques.

Qin H, Nehete PN, He H, Nehete B, Buchl S, Cha SC, Sastry JK, Kwak LW - J. Biomed. Biotechnol. (2010)

Bottom Line: HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed.With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted.Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Lymphoma and Myeloma, M. D. Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA.

ABSTRACT
HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed. A prime-boost strategy using a novel HIV glycoprotein 120 DNA vaccine was employed to immunize rhesus macaques. The DNA vaccine encoded a chimeric gp120 protein in fusion with monocyte chemoattractant protein-3, which was hypothesized to improve the ability of antigen-presenting cells to capture viral antigen through chemokine receptor-mediated endocytosis. DNA vaccination induced virus-reactive T cells in peripheral blood, detectable by T cell proliferation, INFgamma ELISPOT and sustained IL-6 production, without humoral responses. With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted. Surprisingly, long-term and peptide-specific mucosal memory T-cell immunity was detected in both vaccinated macaques after one year. Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

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The immunization strategy elicited mucosal long term memory T-cell immune responses. Production of IFN-γ by CD3+CD4+ or CD3+CD8+memory T cells isolated from colon was analyzed in the vaccinated macaques one year after final peptide-cocktail boost.  Lamina propria lymphocytes (LPL) from colon biopsy samples were stimulated with peptide-mix or mitogens for 6 h. Both untreated (control) and stimulated cells were stained for surface markers, followed by fixation, permeabilization, and intracellular staining of IFN-γ. Live cells were identified by gating on Aqua-negative cells. The cells gated on CD3+CD4+ and CD3+CD8+ were further separated as memory population according to the expression of CD95 (data not shown). The percentage values indicate the population of IFN-γ—producing CD3+CD95+CD4+ or CD3+CD95+CD8+ lymphocytes.
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fig2: The immunization strategy elicited mucosal long term memory T-cell immune responses. Production of IFN-γ by CD3+CD4+ or CD3+CD8+memory T cells isolated from colon was analyzed in the vaccinated macaques one year after final peptide-cocktail boost. Lamina propria lymphocytes (LPL) from colon biopsy samples were stimulated with peptide-mix or mitogens for 6 h. Both untreated (control) and stimulated cells were stained for surface markers, followed by fixation, permeabilization, and intracellular staining of IFN-γ. Live cells were identified by gating on Aqua-negative cells. The cells gated on CD3+CD4+ and CD3+CD8+ were further separated as memory population according to the expression of CD95 (data not shown). The percentage values indicate the population of IFN-γ—producing CD3+CD95+CD4+ or CD3+CD95+CD8+ lymphocytes.

Mentions: We analyzed colon biopsy samples collected from the macaques one year after the final peptide-cocktail boost. During this year-long rest period the two vaccinated macaques received no further treatment. Surprisingly, antigen-specific CD4 and CD8 memory T cells were detected in lamina propria lymphocytes (LPL) isolated from the colon, suggesting long-term mucosal immunity. Specifically, after in vitro stimulation with the peptide-mix, subsets of IFN-γ-producing CD3+CD4+CD95+ and CD3+CD8+CD95+ T cells were readily detected in both vaccinated macaques (Figure 2). The memory T cell response was found only in LPL samples, but not in PBMC (Figure 2). These results suggest that the immunization regimen induced mucosal memory cellular immune responses, which likely resulted from directly delivering viral antigen to the gastrointestinal mucosa by nasogastric administration of the peptide-cocktail.


Prime-boost vaccination using chemokine-fused gp120 DNA and HIV envelope peptides activates both immediate and long-term memory cellular responses in rhesus macaques.

Qin H, Nehete PN, He H, Nehete B, Buchl S, Cha SC, Sastry JK, Kwak LW - J. Biomed. Biotechnol. (2010)

The immunization strategy elicited mucosal long term memory T-cell immune responses. Production of IFN-γ by CD3+CD4+ or CD3+CD8+memory T cells isolated from colon was analyzed in the vaccinated macaques one year after final peptide-cocktail boost.  Lamina propria lymphocytes (LPL) from colon biopsy samples were stimulated with peptide-mix or mitogens for 6 h. Both untreated (control) and stimulated cells were stained for surface markers, followed by fixation, permeabilization, and intracellular staining of IFN-γ. Live cells were identified by gating on Aqua-negative cells. The cells gated on CD3+CD4+ and CD3+CD8+ were further separated as memory population according to the expression of CD95 (data not shown). The percentage values indicate the population of IFN-γ—producing CD3+CD95+CD4+ or CD3+CD95+CD8+ lymphocytes.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2864514&req=5

fig2: The immunization strategy elicited mucosal long term memory T-cell immune responses. Production of IFN-γ by CD3+CD4+ or CD3+CD8+memory T cells isolated from colon was analyzed in the vaccinated macaques one year after final peptide-cocktail boost. Lamina propria lymphocytes (LPL) from colon biopsy samples were stimulated with peptide-mix or mitogens for 6 h. Both untreated (control) and stimulated cells were stained for surface markers, followed by fixation, permeabilization, and intracellular staining of IFN-γ. Live cells were identified by gating on Aqua-negative cells. The cells gated on CD3+CD4+ and CD3+CD8+ were further separated as memory population according to the expression of CD95 (data not shown). The percentage values indicate the population of IFN-γ—producing CD3+CD95+CD4+ or CD3+CD95+CD8+ lymphocytes.
Mentions: We analyzed colon biopsy samples collected from the macaques one year after the final peptide-cocktail boost. During this year-long rest period the two vaccinated macaques received no further treatment. Surprisingly, antigen-specific CD4 and CD8 memory T cells were detected in lamina propria lymphocytes (LPL) isolated from the colon, suggesting long-term mucosal immunity. Specifically, after in vitro stimulation with the peptide-mix, subsets of IFN-γ-producing CD3+CD4+CD95+ and CD3+CD8+CD95+ T cells were readily detected in both vaccinated macaques (Figure 2). The memory T cell response was found only in LPL samples, but not in PBMC (Figure 2). These results suggest that the immunization regimen induced mucosal memory cellular immune responses, which likely resulted from directly delivering viral antigen to the gastrointestinal mucosa by nasogastric administration of the peptide-cocktail.

Bottom Line: HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed.With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted.Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

View Article: PubMed Central - PubMed

Affiliation: Department of Lymphoma and Myeloma, M. D. Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA.

ABSTRACT
HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed. A prime-boost strategy using a novel HIV glycoprotein 120 DNA vaccine was employed to immunize rhesus macaques. The DNA vaccine encoded a chimeric gp120 protein in fusion with monocyte chemoattractant protein-3, which was hypothesized to improve the ability of antigen-presenting cells to capture viral antigen through chemokine receptor-mediated endocytosis. DNA vaccination induced virus-reactive T cells in peripheral blood, detectable by T cell proliferation, INFgamma ELISPOT and sustained IL-6 production, without humoral responses. With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted. Surprisingly, long-term and peptide-specific mucosal memory T-cell immunity was detected in both vaccinated macaques after one year. Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

Show MeSH