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CD8+ DC, but Not CD8(-)DC, isolated from BCG-infected mice reduces pathological reactions induced by mycobacterial challenge infection.

Gao X, Wang S, Fan Y, Bai H, Yang J, Yang X - PLoS ONE (2010)

Bottom Line: The adoptive transfer of the CD8alpha(-)DC from the infected mice (iCD8(-) DC) not only failed to reduce bacterial growth, but enhanced inflammation characterized by diffuse heavy cellular infiltration.Notably, iCD8(-) DC produced significantly higher levels of IL-10 than iCD8+ DC and promoted more Th2 cytokine responses in in vitro DC-T cell co-culture and in vivo adoptive transfer experiments.The data indicate that in vivo BCG-primed CD8+ DC is the dominant DC subset in inducing protective immunity especially for reducing pathological reactions in infected tissues.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Infection and Immunity, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.

ABSTRACT

Background: Tuberculosis is a mycobacterial infection causing worldwide public health problems but the available vaccine is far from ideal. Type-1 T cell immunity has been shown to be critical for host defence against tuberculosis infection, but the role of dendritic cell (DC) subsets in pathogenesis of mycobacterial infection remains unclear.

Methodology/principal findings: We examined the effectiveness of dendritic cell (DC) subsets in BCG-infected mice in generating immune responses beneficial for pathogen clearance and reduction of pathological reactions in the tissues following challenge infection. Our data showed that only the adoptive transfer of the subset of CD8alpha+ DC isolated from infected mice (iCD8+ DC) generated significant protection, demonstrated by less mycobacterial growth and pathological changes in the lung and liver tissues in iCD8+ DC recipients than sham-treated control mice. The adoptive transfer of the CD8alpha(-)DC from the infected mice (iCD8(-) DC) not only failed to reduce bacterial growth, but enhanced inflammation characterized by diffuse heavy cellular infiltration. Notably, iCD8(-) DC produced significantly higher levels of IL-10 than iCD8+ DC and promoted more Th2 cytokine responses in in vitro DC-T cell co-culture and in vivo adoptive transfer experiments.

Conclusions/significance: The data indicate that in vivo BCG-primed CD8+ DC is the dominant DC subset in inducing protective immunity especially for reducing pathological reactions in infected tissues. The finding has implications for the rational improvement of the prophylactic and therapeutic approaches for controlling tuberculosis infection and related diseases.

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Effects of different DC subsets adoptive transfer on Th1-related cytokine production by recipient mice following challenge infection.A: The recipient mice (C57BL/6, n = 4/group) of i.v. adoptive transferred iCD8+ DC or iCD8- DC subsets and PBS treated control mice were challenged i.v. with BCG and sacrificed at day 21 post challenge as described in Materials and Methods. A, splenocytes were cultured at the concentration of 7.5×106 cells/well using HK-BCG as stimulator. Culture supernatants were harvested at 72 h and the cytokines were measured by ELISA. B&C, lungs and livers were homogenized in 10 ml cold protein-free D-PBS and centrifuged. The cytokines levels in the lung (B) and liver (C) were measured by ELISA. Data are presented as mean±SD of each group. One representative experiment of three independent experiments is shown. *p<0.05; **, p<0.01.
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pone-0009281-g007: Effects of different DC subsets adoptive transfer on Th1-related cytokine production by recipient mice following challenge infection.A: The recipient mice (C57BL/6, n = 4/group) of i.v. adoptive transferred iCD8+ DC or iCD8- DC subsets and PBS treated control mice were challenged i.v. with BCG and sacrificed at day 21 post challenge as described in Materials and Methods. A, splenocytes were cultured at the concentration of 7.5×106 cells/well using HK-BCG as stimulator. Culture supernatants were harvested at 72 h and the cytokines were measured by ELISA. B&C, lungs and livers were homogenized in 10 ml cold protein-free D-PBS and centrifuged. The cytokines levels in the lung (B) and liver (C) were measured by ELISA. Data are presented as mean±SD of each group. One representative experiment of three independent experiments is shown. *p<0.05; **, p<0.01.

Mentions: Since the type of immune responses plays a critical role in protection against mycobacterial infection, we further examined the T cell cytokine patterns and antibody responses in the recipients of different DC subsets in order to elucidate the mechanism underlying the difference in protection. As shown in Figure 7A, significant difference in the production of BCG driven type-1 related cytokines (IFN-γ and IL-12) by bulk cultured spleen cells was observed between the different groups following challenge infection. Specifically, the recipient of iCD8+ DC showed significantly higher IFN-γ production than the control mice without cell transfer. Analysis of cytokine patterns in the local tissues also showed higher IL-12 and IFN-γ levels in the lung (Figure 7B) and liver (Figure 7C) of the iCD8+ recipient mice compared to sham control groups and iCD8− DC recipient mice. Serum antibody analysis showed low titers of BCG specific IgG2a and IgG1 antibodies in all the groups and no significant difference was observed among the groups (data not shown).


CD8+ DC, but Not CD8(-)DC, isolated from BCG-infected mice reduces pathological reactions induced by mycobacterial challenge infection.

Gao X, Wang S, Fan Y, Bai H, Yang J, Yang X - PLoS ONE (2010)

Effects of different DC subsets adoptive transfer on Th1-related cytokine production by recipient mice following challenge infection.A: The recipient mice (C57BL/6, n = 4/group) of i.v. adoptive transferred iCD8+ DC or iCD8- DC subsets and PBS treated control mice were challenged i.v. with BCG and sacrificed at day 21 post challenge as described in Materials and Methods. A, splenocytes were cultured at the concentration of 7.5×106 cells/well using HK-BCG as stimulator. Culture supernatants were harvested at 72 h and the cytokines were measured by ELISA. B&C, lungs and livers were homogenized in 10 ml cold protein-free D-PBS and centrifuged. The cytokines levels in the lung (B) and liver (C) were measured by ELISA. Data are presented as mean±SD of each group. One representative experiment of three independent experiments is shown. *p<0.05; **, p<0.01.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2823775&req=5

pone-0009281-g007: Effects of different DC subsets adoptive transfer on Th1-related cytokine production by recipient mice following challenge infection.A: The recipient mice (C57BL/6, n = 4/group) of i.v. adoptive transferred iCD8+ DC or iCD8- DC subsets and PBS treated control mice were challenged i.v. with BCG and sacrificed at day 21 post challenge as described in Materials and Methods. A, splenocytes were cultured at the concentration of 7.5×106 cells/well using HK-BCG as stimulator. Culture supernatants were harvested at 72 h and the cytokines were measured by ELISA. B&C, lungs and livers were homogenized in 10 ml cold protein-free D-PBS and centrifuged. The cytokines levels in the lung (B) and liver (C) were measured by ELISA. Data are presented as mean±SD of each group. One representative experiment of three independent experiments is shown. *p<0.05; **, p<0.01.
Mentions: Since the type of immune responses plays a critical role in protection against mycobacterial infection, we further examined the T cell cytokine patterns and antibody responses in the recipients of different DC subsets in order to elucidate the mechanism underlying the difference in protection. As shown in Figure 7A, significant difference in the production of BCG driven type-1 related cytokines (IFN-γ and IL-12) by bulk cultured spleen cells was observed between the different groups following challenge infection. Specifically, the recipient of iCD8+ DC showed significantly higher IFN-γ production than the control mice without cell transfer. Analysis of cytokine patterns in the local tissues also showed higher IL-12 and IFN-γ levels in the lung (Figure 7B) and liver (Figure 7C) of the iCD8+ recipient mice compared to sham control groups and iCD8− DC recipient mice. Serum antibody analysis showed low titers of BCG specific IgG2a and IgG1 antibodies in all the groups and no significant difference was observed among the groups (data not shown).

Bottom Line: The adoptive transfer of the CD8alpha(-)DC from the infected mice (iCD8(-) DC) not only failed to reduce bacterial growth, but enhanced inflammation characterized by diffuse heavy cellular infiltration.Notably, iCD8(-) DC produced significantly higher levels of IL-10 than iCD8+ DC and promoted more Th2 cytokine responses in in vitro DC-T cell co-culture and in vivo adoptive transfer experiments.The data indicate that in vivo BCG-primed CD8+ DC is the dominant DC subset in inducing protective immunity especially for reducing pathological reactions in infected tissues.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Infection and Immunity, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.

ABSTRACT

Background: Tuberculosis is a mycobacterial infection causing worldwide public health problems but the available vaccine is far from ideal. Type-1 T cell immunity has been shown to be critical for host defence against tuberculosis infection, but the role of dendritic cell (DC) subsets in pathogenesis of mycobacterial infection remains unclear.

Methodology/principal findings: We examined the effectiveness of dendritic cell (DC) subsets in BCG-infected mice in generating immune responses beneficial for pathogen clearance and reduction of pathological reactions in the tissues following challenge infection. Our data showed that only the adoptive transfer of the subset of CD8alpha+ DC isolated from infected mice (iCD8+ DC) generated significant protection, demonstrated by less mycobacterial growth and pathological changes in the lung and liver tissues in iCD8+ DC recipients than sham-treated control mice. The adoptive transfer of the CD8alpha(-)DC from the infected mice (iCD8(-) DC) not only failed to reduce bacterial growth, but enhanced inflammation characterized by diffuse heavy cellular infiltration. Notably, iCD8(-) DC produced significantly higher levels of IL-10 than iCD8+ DC and promoted more Th2 cytokine responses in in vitro DC-T cell co-culture and in vivo adoptive transfer experiments.

Conclusions/significance: The data indicate that in vivo BCG-primed CD8+ DC is the dominant DC subset in inducing protective immunity especially for reducing pathological reactions in infected tissues. The finding has implications for the rational improvement of the prophylactic and therapeutic approaches for controlling tuberculosis infection and related diseases.

Show MeSH
Related in: MedlinePlus