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Immune evasion by Yersinia enterocolitica: differential targeting of dendritic cell subpopulations in vivo.

Autenrieth SE, Linzer TR, Hiller C, Keller B, Warnke P, Köberle M, Bohn E, Biedermann T, Bühring HJ, Hämmerling GJ, Rammensee HG, Autenrieth IB - PLoS Pathog. (2010)

Bottom Line: The decreased number of DC subsets, which was dependent on TLR4 and TRIF signaling, was the result of a faster proliferation and suppressed de novo DC generation.The data suggest that these effects might be caused directly by injection of Yops into DCs and indirectly by affecting the homeostasis of CD4(+) and CD8α(+) DCs.These events may contribute to reduced T-cell proliferation and immune evasion of Ye.

View Article: PubMed Central - PubMed

Affiliation: Interfakultäres Institut für Zellbiologie, Universität Tübingen, Tübingen, Germany. Stella.Autenrieth@medizin.uni-tuebingen.de

ABSTRACT
CD4(+) T cells are essential for the control of Yersinia enterocolitica (Ye) infection in mice. Ye can inhibit dendritic cell (DC) antigen uptake and degradation, maturation and subsequently T-cell activation in vitro. Here we investigated the effects of Ye infection on splenic DCs and T-cell proliferation in an experimental mouse infection model. We found that OVA-specific CD4(+) T cells had a reduced potential to proliferate when stimulated with OVA after infection with Ye compared to control mice. Additionally, proliferation of OVA-specific CD4(+) T cells was markedly reduced when cultured with splenic CD8α(+) DCs from Ye infected mice in the presence of OVA. In contrast, T-cell proliferation was not impaired in cultures with CD4(+) or CD4(-)CD8α(-) DCs isolated from Ye infected mice. However, OVA uptake and degradation as well as cytokine production were impaired in CD8α(+) DCs, but not in CD4(+) and CD4(-)CD8α(-) DCs after Ye infection. Pathogenicity factors (Yops) from Ye were most frequently injected into CD8α(+) DCs, resulting in less MHC class II and CD86 expression than on non-injected CD8α(+) DCs. Three days post infection with Ye the number of splenic CD8α(+) and CD4(+) DCs was reduced by 50% and 90%, respectively. The decreased number of DC subsets, which was dependent on TLR4 and TRIF signaling, was the result of a faster proliferation and suppressed de novo DC generation. Together, we show that Ye infection negatively regulates the stimulatory capacity of some but not all splenic DC subpopulations in vivo. This leads to differential antigen uptake and degradation, cytokine production, cell loss, and cell death rates in various DC subpopulations. The data suggest that these effects might be caused directly by injection of Yops into DCs and indirectly by affecting the homeostasis of CD4(+) and CD8α(+) DCs. These events may contribute to reduced T-cell proliferation and immune evasion of Ye.

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Analysis of antigen uptake and degradation by DCs from mice infected with Ye.(A–C) C57BL/6 mice were injected i.v. with 5×104 Ye pYV+ or PBS. 24 h or three days p.i. OVA-AlexaFluor647 and DQ-OVA was administered i.v.. Uptake of OVA-AlexaFluor647 and degradation of DQ-OVA by DC subpopulations in the spleen was analyzed 1 h later by flow cytometry. (A) Dot plots show OVA-AlexaFluor647+ and DQ-OVA+ DC subpopulations from the mice as indicated. The percentages of cells in the upper two quadrants are indicated. (B) The diagram shows the percentage of OVA-AlexaFluor647+ DC subpopulations as analyzed in (A, upper two quadrants). (C) DQ-OVA degradation by DC subpopulations was analyzed as the percentage of cells in the upper right quadrant/percentage of cells in the two upper quadrants x 100% as shown in A. The data are representative of 2 experiments with 5 mice per group. * indicates statistically significant differences.
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ppat-1001212-g002: Analysis of antigen uptake and degradation by DCs from mice infected with Ye.(A–C) C57BL/6 mice were injected i.v. with 5×104 Ye pYV+ or PBS. 24 h or three days p.i. OVA-AlexaFluor647 and DQ-OVA was administered i.v.. Uptake of OVA-AlexaFluor647 and degradation of DQ-OVA by DC subpopulations in the spleen was analyzed 1 h later by flow cytometry. (A) Dot plots show OVA-AlexaFluor647+ and DQ-OVA+ DC subpopulations from the mice as indicated. The percentages of cells in the upper two quadrants are indicated. (B) The diagram shows the percentage of OVA-AlexaFluor647+ DC subpopulations as analyzed in (A, upper two quadrants). (C) DQ-OVA degradation by DC subpopulations was analyzed as the percentage of cells in the upper right quadrant/percentage of cells in the two upper quadrants x 100% as shown in A. The data are representative of 2 experiments with 5 mice per group. * indicates statistically significant differences.

Mentions: To further elucidate whether antigen uptake and/or degradation by DC subpopulations is modulated by Ye in vivo, mice were co-injected i.v. 24 h or three days p.i. with AlexaFluor647-labeled OVA protein to analyze OVA uptake, and DQ-OVA, a self-quenched fluorescently-labeled OVA protein, which emits fluorescence upon proteolytic degradation in endosomes and lysosomes [41]. OVA uptake and degradation was analyzed 1 h post OVA administration by flow cytometry. In line with previous data [20], CD8α+ DCs displayed a higher uptake of OVA-Alexa647 (Fig. 2A) than CD4+ or CD4−CD8α− DCs (Fig. 2A and B). 24 h and three days p.i. with Ye, we observed 20% or 80% less OVA-Alexa647+CD8α+ DCs, respectively, compared to PBS-treated mice. The percentage of OVA-Alexa647+CD4+ and CD4−CD8α− DCs 24 h post Ye infection was similar to that of PBS-treated mice (Fig. 2A and B). Interestingly, we found that the percentage of OVA-Alexa647+CD4+ and CD4−CD8α− DCs was increased 1,5- to 4-fold three days p.i. with Ye, respectively (Fig. 2A and B).


Immune evasion by Yersinia enterocolitica: differential targeting of dendritic cell subpopulations in vivo.

Autenrieth SE, Linzer TR, Hiller C, Keller B, Warnke P, Köberle M, Bohn E, Biedermann T, Bühring HJ, Hämmerling GJ, Rammensee HG, Autenrieth IB - PLoS Pathog. (2010)

Analysis of antigen uptake and degradation by DCs from mice infected with Ye.(A–C) C57BL/6 mice were injected i.v. with 5×104 Ye pYV+ or PBS. 24 h or three days p.i. OVA-AlexaFluor647 and DQ-OVA was administered i.v.. Uptake of OVA-AlexaFluor647 and degradation of DQ-OVA by DC subpopulations in the spleen was analyzed 1 h later by flow cytometry. (A) Dot plots show OVA-AlexaFluor647+ and DQ-OVA+ DC subpopulations from the mice as indicated. The percentages of cells in the upper two quadrants are indicated. (B) The diagram shows the percentage of OVA-AlexaFluor647+ DC subpopulations as analyzed in (A, upper two quadrants). (C) DQ-OVA degradation by DC subpopulations was analyzed as the percentage of cells in the upper right quadrant/percentage of cells in the two upper quadrants x 100% as shown in A. The data are representative of 2 experiments with 5 mice per group. * indicates statistically significant differences.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2991265&req=5

ppat-1001212-g002: Analysis of antigen uptake and degradation by DCs from mice infected with Ye.(A–C) C57BL/6 mice were injected i.v. with 5×104 Ye pYV+ or PBS. 24 h or three days p.i. OVA-AlexaFluor647 and DQ-OVA was administered i.v.. Uptake of OVA-AlexaFluor647 and degradation of DQ-OVA by DC subpopulations in the spleen was analyzed 1 h later by flow cytometry. (A) Dot plots show OVA-AlexaFluor647+ and DQ-OVA+ DC subpopulations from the mice as indicated. The percentages of cells in the upper two quadrants are indicated. (B) The diagram shows the percentage of OVA-AlexaFluor647+ DC subpopulations as analyzed in (A, upper two quadrants). (C) DQ-OVA degradation by DC subpopulations was analyzed as the percentage of cells in the upper right quadrant/percentage of cells in the two upper quadrants x 100% as shown in A. The data are representative of 2 experiments with 5 mice per group. * indicates statistically significant differences.
Mentions: To further elucidate whether antigen uptake and/or degradation by DC subpopulations is modulated by Ye in vivo, mice were co-injected i.v. 24 h or three days p.i. with AlexaFluor647-labeled OVA protein to analyze OVA uptake, and DQ-OVA, a self-quenched fluorescently-labeled OVA protein, which emits fluorescence upon proteolytic degradation in endosomes and lysosomes [41]. OVA uptake and degradation was analyzed 1 h post OVA administration by flow cytometry. In line with previous data [20], CD8α+ DCs displayed a higher uptake of OVA-Alexa647 (Fig. 2A) than CD4+ or CD4−CD8α− DCs (Fig. 2A and B). 24 h and three days p.i. with Ye, we observed 20% or 80% less OVA-Alexa647+CD8α+ DCs, respectively, compared to PBS-treated mice. The percentage of OVA-Alexa647+CD4+ and CD4−CD8α− DCs 24 h post Ye infection was similar to that of PBS-treated mice (Fig. 2A and B). Interestingly, we found that the percentage of OVA-Alexa647+CD4+ and CD4−CD8α− DCs was increased 1,5- to 4-fold three days p.i. with Ye, respectively (Fig. 2A and B).

Bottom Line: The decreased number of DC subsets, which was dependent on TLR4 and TRIF signaling, was the result of a faster proliferation and suppressed de novo DC generation.The data suggest that these effects might be caused directly by injection of Yops into DCs and indirectly by affecting the homeostasis of CD4(+) and CD8α(+) DCs.These events may contribute to reduced T-cell proliferation and immune evasion of Ye.

View Article: PubMed Central - PubMed

Affiliation: Interfakultäres Institut für Zellbiologie, Universität Tübingen, Tübingen, Germany. Stella.Autenrieth@medizin.uni-tuebingen.de

ABSTRACT
CD4(+) T cells are essential for the control of Yersinia enterocolitica (Ye) infection in mice. Ye can inhibit dendritic cell (DC) antigen uptake and degradation, maturation and subsequently T-cell activation in vitro. Here we investigated the effects of Ye infection on splenic DCs and T-cell proliferation in an experimental mouse infection model. We found that OVA-specific CD4(+) T cells had a reduced potential to proliferate when stimulated with OVA after infection with Ye compared to control mice. Additionally, proliferation of OVA-specific CD4(+) T cells was markedly reduced when cultured with splenic CD8α(+) DCs from Ye infected mice in the presence of OVA. In contrast, T-cell proliferation was not impaired in cultures with CD4(+) or CD4(-)CD8α(-) DCs isolated from Ye infected mice. However, OVA uptake and degradation as well as cytokine production were impaired in CD8α(+) DCs, but not in CD4(+) and CD4(-)CD8α(-) DCs after Ye infection. Pathogenicity factors (Yops) from Ye were most frequently injected into CD8α(+) DCs, resulting in less MHC class II and CD86 expression than on non-injected CD8α(+) DCs. Three days post infection with Ye the number of splenic CD8α(+) and CD4(+) DCs was reduced by 50% and 90%, respectively. The decreased number of DC subsets, which was dependent on TLR4 and TRIF signaling, was the result of a faster proliferation and suppressed de novo DC generation. Together, we show that Ye infection negatively regulates the stimulatory capacity of some but not all splenic DC subpopulations in vivo. This leads to differential antigen uptake and degradation, cytokine production, cell loss, and cell death rates in various DC subpopulations. The data suggest that these effects might be caused directly by injection of Yops into DCs and indirectly by affecting the homeostasis of CD4(+) and CD8α(+) DCs. These events may contribute to reduced T-cell proliferation and immune evasion of Ye.

Show MeSH
Related in: MedlinePlus