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Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses.

Provine NM, Badamchi-Zadeh A, Bricault CA, Penaloza-MacMaster P, Larocca RA, Borducchi EN, Seaman MS, Barouch DH - J. Virol. (2016)

Bottom Line: Upon CD4(+)T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals.The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen.These data demonstrate that the time when CD4(+)T cell help signals must be provided is more dynamic and flexible than previously appreciated.

View Article: PubMed Central - PubMed

Affiliation: Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.

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Related in: MedlinePlus

Development of antigen-specific CD4+ T cell responses after transient depletion of CD4+ T cells. (A) Gating scheme for characterization of antigen-specific CD4+ T cells by intracellular cytokine staining. SSC, side scatter; FSC, forward scatter. (B) C57BL/6 mice were depleted of CD4+ T cells at immunization or left untreated and immunized intramuscularly with 1010 vp of Ad26-SIV Env. Spleens and iliac (draining) LNs were collected on day 60 postimmunization, and intracellular cytokine staining was performed to detect the production of IL-21, IFN-γ, and IL-2 by CD44+ CD4+ T cells following stimulation with an overlapping SIV Env peptide pool. Means ± standard errors of the means are shown. The horizontal dotted line denotes the limit of detection for the assay (n = 10/group pooled from two experiments).
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Figure 6: Development of antigen-specific CD4+ T cell responses after transient depletion of CD4+ T cells. (A) Gating scheme for characterization of antigen-specific CD4+ T cells by intracellular cytokine staining. SSC, side scatter; FSC, forward scatter. (B) C57BL/6 mice were depleted of CD4+ T cells at immunization or left untreated and immunized intramuscularly with 1010 vp of Ad26-SIV Env. Spleens and iliac (draining) LNs were collected on day 60 postimmunization, and intracellular cytokine staining was performed to detect the production of IL-21, IFN-γ, and IL-2 by CD44+ CD4+ T cells following stimulation with an overlapping SIV Env peptide pool. Means ± standard errors of the means are shown. The horizontal dotted line denotes the limit of detection for the assay (n = 10/group pooled from two experiments).

Mentions: We next sought to characterize the recovering CD4+ T cells to determine if any of the cells were specific for the SIV Env antigen. To test this, on day 60 postimmunization, CD4+ T cells from the spleen and iliac LNs were stimulated with an overlapping SIV Env peptide pool, and cytokine production was measured by intracellular cytokine staining (Fig. 6A). CD4+ T cells from both untreated control mice and mice treated with anti-CD4 antibody at priming produced modest amounts of IL-21, IFN-γ, and IL-2 in response to SIV Env peptide stimulation (Fig. 6B). Antigen-specific CD4+ T cells were detected in both the spleen and iliac LNs of mice from both groups. IL-21-producing CD4+ T cells were identified, and as CD4+ T cell-derived IL-21 is a critical cytokine for germinal center responses (35), it likely partially explains how delayed germinal center responses are induced. These data demonstrate that in the context of Ad vector immunization following transient CD4+ T cell depletion, antigen-specific CD4+ T cells expand upon recovery.


Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses.

Provine NM, Badamchi-Zadeh A, Bricault CA, Penaloza-MacMaster P, Larocca RA, Borducchi EN, Seaman MS, Barouch DH - J. Virol. (2016)

Development of antigen-specific CD4+ T cell responses after transient depletion of CD4+ T cells. (A) Gating scheme for characterization of antigen-specific CD4+ T cells by intracellular cytokine staining. SSC, side scatter; FSC, forward scatter. (B) C57BL/6 mice were depleted of CD4+ T cells at immunization or left untreated and immunized intramuscularly with 1010 vp of Ad26-SIV Env. Spleens and iliac (draining) LNs were collected on day 60 postimmunization, and intracellular cytokine staining was performed to detect the production of IL-21, IFN-γ, and IL-2 by CD44+ CD4+ T cells following stimulation with an overlapping SIV Env peptide pool. Means ± standard errors of the means are shown. The horizontal dotted line denotes the limit of detection for the assay (n = 10/group pooled from two experiments).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4836333&req=5

Figure 6: Development of antigen-specific CD4+ T cell responses after transient depletion of CD4+ T cells. (A) Gating scheme for characterization of antigen-specific CD4+ T cells by intracellular cytokine staining. SSC, side scatter; FSC, forward scatter. (B) C57BL/6 mice were depleted of CD4+ T cells at immunization or left untreated and immunized intramuscularly with 1010 vp of Ad26-SIV Env. Spleens and iliac (draining) LNs were collected on day 60 postimmunization, and intracellular cytokine staining was performed to detect the production of IL-21, IFN-γ, and IL-2 by CD44+ CD4+ T cells following stimulation with an overlapping SIV Env peptide pool. Means ± standard errors of the means are shown. The horizontal dotted line denotes the limit of detection for the assay (n = 10/group pooled from two experiments).
Mentions: We next sought to characterize the recovering CD4+ T cells to determine if any of the cells were specific for the SIV Env antigen. To test this, on day 60 postimmunization, CD4+ T cells from the spleen and iliac LNs were stimulated with an overlapping SIV Env peptide pool, and cytokine production was measured by intracellular cytokine staining (Fig. 6A). CD4+ T cells from both untreated control mice and mice treated with anti-CD4 antibody at priming produced modest amounts of IL-21, IFN-γ, and IL-2 in response to SIV Env peptide stimulation (Fig. 6B). Antigen-specific CD4+ T cells were detected in both the spleen and iliac LNs of mice from both groups. IL-21-producing CD4+ T cells were identified, and as CD4+ T cell-derived IL-21 is a critical cytokine for germinal center responses (35), it likely partially explains how delayed germinal center responses are induced. These data demonstrate that in the context of Ad vector immunization following transient CD4+ T cell depletion, antigen-specific CD4+ T cells expand upon recovery.

Bottom Line: Upon CD4(+)T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals.The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen.These data demonstrate that the time when CD4(+)T cell help signals must be provided is more dynamic and flexible than previously appreciated.

View Article: PubMed Central - PubMed

Affiliation: Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.

Show MeSH
Related in: MedlinePlus