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A DNA vaccine encoding multiple HIV CD4 epitopes elicits vigorous polyfunctional, long-lived CD4+ and CD8+ T cell responses.

Rosa DS, Ribeiro SP, Almeida RR, Mairena EC, Postól E, Kalil J, Cunha-Neto E - PLoS ONE (2011)

Bottom Line: Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection.The vaccine also generated long-lived central and effector memory CD4(+) T cells, a desirable feature for T-cell based vaccines.By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+) T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+) T cells and antibody responses- elicited by other HIV immunogens.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Clinical Immunology and Allergy-LIM60, Division of Clinical Immunology and Allergy, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil.

ABSTRACT
T-cell based vaccines against HIV have the goal of limiting both transmission and disease progression by inducing broad and functionally relevant T cell responses. Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection. CD4(+) T cells are important for the generation and maintenance of functional CD8(+) cytotoxic T cells. We have recently developed a DNA vaccine encoding 18 conserved multiple HLA-DR-binding HIV-1 CD4 epitopes (HIVBr18), capable of eliciting broad CD4(+) T cell responses in multiple HLA class II transgenic mice. Here, we evaluated the breadth and functional profile of HIVBr18-induced immune responses in BALB/c mice. Immunized mice displayed high-magnitude, broad CD4(+)/CD8(+) T cell responses, and 8/18 vaccine-encoded peptides were recognized. In addition, HIVBr18 immunization was able to induce polyfunctional CD4(+) and CD8(+) T cells that proliferate and produce any two cytokines (IFNγ/TNFα, IFNγ/IL-2 or TNFα/IL-2) simultaneously in response to HIV-1 peptides. For CD4(+) T cells exclusively, we also detected cells that proliferate and produce all three tested cytokines simultaneously (IFNγ/TNFα/IL-2). The vaccine also generated long-lived central and effector memory CD4(+) T cells, a desirable feature for T-cell based vaccines. By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+) T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+) T cells and antibody responses- elicited by other HIV immunogens.

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Immunization with HIVBr18 induces specific CD4+ and CD8+ T cells that proliferate and produce type 1 cytokines simultaneously.Two weeks after the last immunization with HIVBr18 or the empty vector pVAX1, spleen cells from 6 BALB/c mice were labeled with CFSE (1.25 µM) and cultured for 4 days in the presence of pooled HIV-1 peptides or medium only. On day 4, cells were pulsed for 12 hours with pooled peptides or medium, in the presence of costimulatory antibody and Brefeldin A. (A) CFSE and intracellular cytokine staining were used to simultaneously assess proliferation and IFNγ, TNFα or IL2 production. Frequencies of antigen-specific cytokine-producing T cells in proliferating (CFSElow) and non-proliferating (CFSEhi) gates are displayed; (B) Proportion of proliferating cells (CFSElow) in the total cytokine gate (sum of % of cytokine producing cells in gated CFSEhi and CFSElow cells); (C) Percentage of cytokine producing CD4+ and CD8+ T cells in proliferating cells (CFSElow) (values of cytokine producing cells in CFSElow population ×100 divided by total CFSElow population).
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pone-0016921-g004: Immunization with HIVBr18 induces specific CD4+ and CD8+ T cells that proliferate and produce type 1 cytokines simultaneously.Two weeks after the last immunization with HIVBr18 or the empty vector pVAX1, spleen cells from 6 BALB/c mice were labeled with CFSE (1.25 µM) and cultured for 4 days in the presence of pooled HIV-1 peptides or medium only. On day 4, cells were pulsed for 12 hours with pooled peptides or medium, in the presence of costimulatory antibody and Brefeldin A. (A) CFSE and intracellular cytokine staining were used to simultaneously assess proliferation and IFNγ, TNFα or IL2 production. Frequencies of antigen-specific cytokine-producing T cells in proliferating (CFSElow) and non-proliferating (CFSEhi) gates are displayed; (B) Proportion of proliferating cells (CFSElow) in the total cytokine gate (sum of % of cytokine producing cells in gated CFSEhi and CFSElow cells); (C) Percentage of cytokine producing CD4+ and CD8+ T cells in proliferating cells (CFSElow) (values of cytokine producing cells in CFSElow population ×100 divided by total CFSElow population).

Mentions: We next examined whether antigen-specific proliferating T cells were the major cytokine producers. As shown in Figures 4A and B, the vast majority (ca. 80%) of CD4+ and CD8+ T cells that produced the effector cytokines IFNγ and TNFα are within the proliferating (CFSElow) population. In contrast, 50% of IL-2 producing T cells also proliferated (Figure 4B). These experiments also showed that mice immunized with HIVBr18 displayed 2.31, 0.37 and 2.80% of HIV-specific CD4+ T cells that proliferated (CFSElow) and produced either IFNγ, IL-2 or TNFα, respectively. A similar response was observed in CD8+ T cells, showing that 0.60, 0.22 and 0.64% of CD8+ T cells proliferated and produced either IFNγ, IL-2 or TNFα, respectively. In contrast, splenocytes from mice immunized with the control pVAX1 displayed a negligible percentage of specific proliferating/cytokine producing T cells (Figure S4).


A DNA vaccine encoding multiple HIV CD4 epitopes elicits vigorous polyfunctional, long-lived CD4+ and CD8+ T cell responses.

Rosa DS, Ribeiro SP, Almeida RR, Mairena EC, Postól E, Kalil J, Cunha-Neto E - PLoS ONE (2011)

Immunization with HIVBr18 induces specific CD4+ and CD8+ T cells that proliferate and produce type 1 cytokines simultaneously.Two weeks after the last immunization with HIVBr18 or the empty vector pVAX1, spleen cells from 6 BALB/c mice were labeled with CFSE (1.25 µM) and cultured for 4 days in the presence of pooled HIV-1 peptides or medium only. On day 4, cells were pulsed for 12 hours with pooled peptides or medium, in the presence of costimulatory antibody and Brefeldin A. (A) CFSE and intracellular cytokine staining were used to simultaneously assess proliferation and IFNγ, TNFα or IL2 production. Frequencies of antigen-specific cytokine-producing T cells in proliferating (CFSElow) and non-proliferating (CFSEhi) gates are displayed; (B) Proportion of proliferating cells (CFSElow) in the total cytokine gate (sum of % of cytokine producing cells in gated CFSEhi and CFSElow cells); (C) Percentage of cytokine producing CD4+ and CD8+ T cells in proliferating cells (CFSElow) (values of cytokine producing cells in CFSElow population ×100 divided by total CFSElow population).
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3037933&req=5

pone-0016921-g004: Immunization with HIVBr18 induces specific CD4+ and CD8+ T cells that proliferate and produce type 1 cytokines simultaneously.Two weeks after the last immunization with HIVBr18 or the empty vector pVAX1, spleen cells from 6 BALB/c mice were labeled with CFSE (1.25 µM) and cultured for 4 days in the presence of pooled HIV-1 peptides or medium only. On day 4, cells were pulsed for 12 hours with pooled peptides or medium, in the presence of costimulatory antibody and Brefeldin A. (A) CFSE and intracellular cytokine staining were used to simultaneously assess proliferation and IFNγ, TNFα or IL2 production. Frequencies of antigen-specific cytokine-producing T cells in proliferating (CFSElow) and non-proliferating (CFSEhi) gates are displayed; (B) Proportion of proliferating cells (CFSElow) in the total cytokine gate (sum of % of cytokine producing cells in gated CFSEhi and CFSElow cells); (C) Percentage of cytokine producing CD4+ and CD8+ T cells in proliferating cells (CFSElow) (values of cytokine producing cells in CFSElow population ×100 divided by total CFSElow population).
Mentions: We next examined whether antigen-specific proliferating T cells were the major cytokine producers. As shown in Figures 4A and B, the vast majority (ca. 80%) of CD4+ and CD8+ T cells that produced the effector cytokines IFNγ and TNFα are within the proliferating (CFSElow) population. In contrast, 50% of IL-2 producing T cells also proliferated (Figure 4B). These experiments also showed that mice immunized with HIVBr18 displayed 2.31, 0.37 and 2.80% of HIV-specific CD4+ T cells that proliferated (CFSElow) and produced either IFNγ, IL-2 or TNFα, respectively. A similar response was observed in CD8+ T cells, showing that 0.60, 0.22 and 0.64% of CD8+ T cells proliferated and produced either IFNγ, IL-2 or TNFα, respectively. In contrast, splenocytes from mice immunized with the control pVAX1 displayed a negligible percentage of specific proliferating/cytokine producing T cells (Figure S4).

Bottom Line: Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection.The vaccine also generated long-lived central and effector memory CD4(+) T cells, a desirable feature for T-cell based vaccines.By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+) T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+) T cells and antibody responses- elicited by other HIV immunogens.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Clinical Immunology and Allergy-LIM60, Division of Clinical Immunology and Allergy, Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil.

ABSTRACT
T-cell based vaccines against HIV have the goal of limiting both transmission and disease progression by inducing broad and functionally relevant T cell responses. Moreover, polyfunctional and long-lived specific memory T cells have been associated to vaccine-induced protection. CD4(+) T cells are important for the generation and maintenance of functional CD8(+) cytotoxic T cells. We have recently developed a DNA vaccine encoding 18 conserved multiple HLA-DR-binding HIV-1 CD4 epitopes (HIVBr18), capable of eliciting broad CD4(+) T cell responses in multiple HLA class II transgenic mice. Here, we evaluated the breadth and functional profile of HIVBr18-induced immune responses in BALB/c mice. Immunized mice displayed high-magnitude, broad CD4(+)/CD8(+) T cell responses, and 8/18 vaccine-encoded peptides were recognized. In addition, HIVBr18 immunization was able to induce polyfunctional CD4(+) and CD8(+) T cells that proliferate and produce any two cytokines (IFNγ/TNFα, IFNγ/IL-2 or TNFα/IL-2) simultaneously in response to HIV-1 peptides. For CD4(+) T cells exclusively, we also detected cells that proliferate and produce all three tested cytokines simultaneously (IFNγ/TNFα/IL-2). The vaccine also generated long-lived central and effector memory CD4(+) T cells, a desirable feature for T-cell based vaccines. By virtue of inducing broad, polyfunctional and long-lived T cell responses against conserved CD4(+) T cell epitopes, combined administration of this vaccine concept may provide sustained help for CD8(+) T cells and antibody responses- elicited by other HIV immunogens.

Show MeSH
Related in: MedlinePlus