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Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells.

Li Causi E, Parikh SC, Chudley L, Layfield DM, Ottensmeier CH, Stevenson FK, Di Genova G - PLoS ONE (2015)

Bottom Line: Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype.These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs.Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines.

View Article: PubMed Central - PubMed

Affiliation: Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.

ABSTRACT
CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines.

No MeSH data available.


Related in: MedlinePlus

Flow cytometric analysis of vaccine-specific and bystander CD4+ T cell responses to TT recall vaccination detected by combined CD40L and cytokine intracellular staining.After a short term (6h) in vitro culture in the absence (CTRL) or in the presence of either TT (10μg/ml), PPD (15μg/ml) or C.Alb (10μg/ml), PBMNC were first stained for surface CD3 and CD4, then permeabilized and stained intracellularly with fluorescent antibodies specific for CD40L and the cytokines IL-2 and IFN-γ. (A) Data from one of the individuals (subject 1) show the gating strategy (top three dot plots) and the detection of vaccine-specific (TT) and bystander (PPD and C.Alb) CD4+ T cell responses before (pre-vaccination) and one week after (week 1) a booster injection of TT. Percentages indicate the frequency of positive events within the CD3+CD4+ lymphocyte population. (B) Kinetics of vaccine-specific and bystander CD4+ T cell responses detected by intracellular CD40L and cytokine staining in the same individual who received a booster vaccination (Wk 0) with TT. Data indicate the frequency of positive cells within the CD3+CD4+ population, obtained from the antigen-stimulated samples after subtracting the frequency of events in the control cultures. Responses were considered positive if they met the criteria described in Materials and Methods. The dotted line shows the cut off value of 0.01%.
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pone.0136717.g002: Flow cytometric analysis of vaccine-specific and bystander CD4+ T cell responses to TT recall vaccination detected by combined CD40L and cytokine intracellular staining.After a short term (6h) in vitro culture in the absence (CTRL) or in the presence of either TT (10μg/ml), PPD (15μg/ml) or C.Alb (10μg/ml), PBMNC were first stained for surface CD3 and CD4, then permeabilized and stained intracellularly with fluorescent antibodies specific for CD40L and the cytokines IL-2 and IFN-γ. (A) Data from one of the individuals (subject 1) show the gating strategy (top three dot plots) and the detection of vaccine-specific (TT) and bystander (PPD and C.Alb) CD4+ T cell responses before (pre-vaccination) and one week after (week 1) a booster injection of TT. Percentages indicate the frequency of positive events within the CD3+CD4+ lymphocyte population. (B) Kinetics of vaccine-specific and bystander CD4+ T cell responses detected by intracellular CD40L and cytokine staining in the same individual who received a booster vaccination (Wk 0) with TT. Data indicate the frequency of positive cells within the CD3+CD4+ population, obtained from the antigen-stimulated samples after subtracting the frequency of events in the control cultures. Responses were considered positive if they met the criteria described in Materials and Methods. The dotted line shows the cut off value of 0.01%.

Mentions: Antigen-specific cells were identified within the CD3+CD4+ population through assessment of CD40L expression, after a short (6h) in vitro antigen re-stimulation. This method ensures stability of phenotypic features and allows analysis of a broader population of antigen-specific cells, compared to longer protocols based on cytokine production only [22–24]. Cells were functionally characterized by evaluating cytokine (IFN-γ, IL-2) production. An example of the gating strategy and data relative to the pre-vaccination and week 1 time points for subject 1, are shown in Fig 2A; the response kinetics up to week 8 from the same individual are shown in Fig 2B.


Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells.

Li Causi E, Parikh SC, Chudley L, Layfield DM, Ottensmeier CH, Stevenson FK, Di Genova G - PLoS ONE (2015)

Flow cytometric analysis of vaccine-specific and bystander CD4+ T cell responses to TT recall vaccination detected by combined CD40L and cytokine intracellular staining.After a short term (6h) in vitro culture in the absence (CTRL) or in the presence of either TT (10μg/ml), PPD (15μg/ml) or C.Alb (10μg/ml), PBMNC were first stained for surface CD3 and CD4, then permeabilized and stained intracellularly with fluorescent antibodies specific for CD40L and the cytokines IL-2 and IFN-γ. (A) Data from one of the individuals (subject 1) show the gating strategy (top three dot plots) and the detection of vaccine-specific (TT) and bystander (PPD and C.Alb) CD4+ T cell responses before (pre-vaccination) and one week after (week 1) a booster injection of TT. Percentages indicate the frequency of positive events within the CD3+CD4+ lymphocyte population. (B) Kinetics of vaccine-specific and bystander CD4+ T cell responses detected by intracellular CD40L and cytokine staining in the same individual who received a booster vaccination (Wk 0) with TT. Data indicate the frequency of positive cells within the CD3+CD4+ population, obtained from the antigen-stimulated samples after subtracting the frequency of events in the control cultures. Responses were considered positive if they met the criteria described in Materials and Methods. The dotted line shows the cut off value of 0.01%.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4557947&req=5

pone.0136717.g002: Flow cytometric analysis of vaccine-specific and bystander CD4+ T cell responses to TT recall vaccination detected by combined CD40L and cytokine intracellular staining.After a short term (6h) in vitro culture in the absence (CTRL) or in the presence of either TT (10μg/ml), PPD (15μg/ml) or C.Alb (10μg/ml), PBMNC were first stained for surface CD3 and CD4, then permeabilized and stained intracellularly with fluorescent antibodies specific for CD40L and the cytokines IL-2 and IFN-γ. (A) Data from one of the individuals (subject 1) show the gating strategy (top three dot plots) and the detection of vaccine-specific (TT) and bystander (PPD and C.Alb) CD4+ T cell responses before (pre-vaccination) and one week after (week 1) a booster injection of TT. Percentages indicate the frequency of positive events within the CD3+CD4+ lymphocyte population. (B) Kinetics of vaccine-specific and bystander CD4+ T cell responses detected by intracellular CD40L and cytokine staining in the same individual who received a booster vaccination (Wk 0) with TT. Data indicate the frequency of positive cells within the CD3+CD4+ population, obtained from the antigen-stimulated samples after subtracting the frequency of events in the control cultures. Responses were considered positive if they met the criteria described in Materials and Methods. The dotted line shows the cut off value of 0.01%.
Mentions: Antigen-specific cells were identified within the CD3+CD4+ population through assessment of CD40L expression, after a short (6h) in vitro antigen re-stimulation. This method ensures stability of phenotypic features and allows analysis of a broader population of antigen-specific cells, compared to longer protocols based on cytokine production only [22–24]. Cells were functionally characterized by evaluating cytokine (IFN-γ, IL-2) production. An example of the gating strategy and data relative to the pre-vaccination and week 1 time points for subject 1, are shown in Fig 2A; the response kinetics up to week 8 from the same individual are shown in Fig 2B.

Bottom Line: Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype.These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs.Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines.

View Article: PubMed Central - PubMed

Affiliation: Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.

ABSTRACT
CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines.

No MeSH data available.


Related in: MedlinePlus