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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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Related in: MedlinePlus

DC subsets from BCG-infected mice show similar BCG load.A real-time RT-PCR using the green fluorescent dye SYBR Green I was applied to determine the relative concentration of BCG mRNA in iCD8+DC and iCD8−DC. The BCG mRNA in different DC subsets was amplified as described in Materials and Methods. The BCG mRNA level was normalized to GAPDH mRNA in different DC subsets demonstrated as ΔCt. ΔCt = Ct (BCG)–Ct (GAPDH), the threshold cycle of a BCG and the threshold cycle of the corresponding GAPDH in the same sample.
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pone-0009281-g009: DC subsets from BCG-infected mice show similar BCG load.A real-time RT-PCR using the green fluorescent dye SYBR Green I was applied to determine the relative concentration of BCG mRNA in iCD8+DC and iCD8−DC. The BCG mRNA in different DC subsets was amplified as described in Materials and Methods. The BCG mRNA level was normalized to GAPDH mRNA in different DC subsets demonstrated as ΔCt. ΔCt = Ct (BCG)–Ct (GAPDH), the threshold cycle of a BCG and the threshold cycle of the corresponding GAPDH in the same sample.

Mentions: A question which needed to be addressed was if the differences observed above for the DC subsets isolated from infected mice in generating protective immunity was due to the potential difference of the subsets in BCG loads, thus the amount of antigens carried. To answer this question, we further analyzed the bacterial loads of the CD8+DC and CD8−DC subsets from BCG infected mice using quantitative RT-PCR. As shown in Figure 9, the BCG mRNA levels in the two DC subsets demonstrated in real-time PCR analysis were comparable. The in vitro culture of either DC subsets showed negative results for viable BCG. The data suggest that the DC subsets are not significantly different in carrying BCG and possibly its antigens.


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)

DC subsets from BCG-infected mice show similar BCG load.A real-time RT-PCR using the green fluorescent dye SYBR Green I was applied to determine the relative concentration of BCG mRNA in iCD8+DC and iCD8−DC. The BCG mRNA in different DC subsets was amplified as described in Materials and Methods. The BCG mRNA level was normalized to GAPDH mRNA in different DC subsets demonstrated as ΔCt. ΔCt = Ct (BCG)–Ct (GAPDH), the threshold cycle of a BCG and the threshold cycle of the corresponding GAPDH in the same sample.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2823775&req=5

pone-0009281-g009: DC subsets from BCG-infected mice show similar BCG load.A real-time RT-PCR using the green fluorescent dye SYBR Green I was applied to determine the relative concentration of BCG mRNA in iCD8+DC and iCD8−DC. The BCG mRNA in different DC subsets was amplified as described in Materials and Methods. The BCG mRNA level was normalized to GAPDH mRNA in different DC subsets demonstrated as ΔCt. ΔCt = Ct (BCG)–Ct (GAPDH), the threshold cycle of a BCG and the threshold cycle of the corresponding GAPDH in the same sample.
Mentions: A question which needed to be addressed was if the differences observed above for the DC subsets isolated from infected mice in generating protective immunity was due to the potential difference of the subsets in BCG loads, thus the amount of antigens carried. To answer this question, we further analyzed the bacterial loads of the CD8+DC and CD8−DC subsets from BCG infected mice using quantitative RT-PCR. As shown in Figure 9, the BCG mRNA levels in the two DC subsets demonstrated in real-time PCR analysis were comparable. The in vitro culture of either DC subsets showed negative results for viable BCG. The data suggest that the DC subsets are not significantly different in carrying BCG and possibly its antigens.

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