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Dendritic cells pulsed with intact Streptococcus pneumoniae elicit both protein- and polysaccharide-specific immunoglobulin isotype responses in vivo through distinct mechanisms.

Colino J, Shen Y, Snapper CM - J. Exp. Med. (2002)

Bottom Line: Immature bone marrow-derived myeloid dendritic cells (BMDCs) are induced to undergo phenotypic maturation and secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-12, and IL-10 when pulsed in vitro with intact Streptococcus pneumoniae.After transfer to naive mice, pulsed BMDCs induce immunoglobulin (Ig) isotype responses specific for both protein and polysaccharide pneumococcal antigens, having in common the requirement for viable BMDCs, T cells, and B7-dependent costimulation in the recipient mice.Whereas primary Ig isotype responses to bacterial proteins uniformly require BMDC expression of major histocompatibility complex class II, CD40, and B7, and the secretion of IL-6, but not IL-12, similar requirements for antipolysaccharide Ig responses were only observed for the IgG1 isotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.

ABSTRACT
Immature bone marrow-derived myeloid dendritic cells (BMDCs) are induced to undergo phenotypic maturation and secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-12, and IL-10 when pulsed in vitro with intact Streptococcus pneumoniae. After transfer to naive mice, pulsed BMDCs induce immunoglobulin (Ig) isotype responses specific for both protein and polysaccharide pneumococcal antigens, having in common the requirement for viable BMDCs, T cells, and B7-dependent costimulation in the recipient mice. Whereas primary Ig isotype responses to bacterial proteins uniformly require BMDC expression of major histocompatibility complex class II, CD40, and B7, and the secretion of IL-6, but not IL-12, similar requirements for antipolysaccharide Ig responses were only observed for the IgG1 isotype.

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S. pneumoniae uptake and BMDC responses to S. pneumoniae in vitro. (A) Time course of internalization of heat-killed S. pneumoniae (JD6/11 strain) labeled with the fluorescent tracer CM-DiI, at the bacteria: BMDC ratios indicated. The dotted line shows the estimated MFI produced by internalization of one diplococcus. (B) Concentrations of cytokine released into the media (left) or cytokine mRNA synthesis (middle) at varying times after addition of S. pneumoniae type 14, or during a 20-h period in the absence of bacteria after exposure to free bacteria for different times (right). (C) S. pneumoniae triggering of BMDC maturation. FACS® analysis of BMDC phenotype after culture for 20 h in the absence (−) or in the presence (+) of 800 heat-killed S. pneumoniae per individual BMDCs. Dotted histograms represent cells stained with isotype-matched control mAbs. The data shown is representative of three independent experiments.
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fig1: S. pneumoniae uptake and BMDC responses to S. pneumoniae in vitro. (A) Time course of internalization of heat-killed S. pneumoniae (JD6/11 strain) labeled with the fluorescent tracer CM-DiI, at the bacteria: BMDC ratios indicated. The dotted line shows the estimated MFI produced by internalization of one diplococcus. (B) Concentrations of cytokine released into the media (left) or cytokine mRNA synthesis (middle) at varying times after addition of S. pneumoniae type 14, or during a 20-h period in the absence of bacteria after exposure to free bacteria for different times (right). (C) S. pneumoniae triggering of BMDC maturation. FACS® analysis of BMDC phenotype after culture for 20 h in the absence (−) or in the presence (+) of 800 heat-killed S. pneumoniae per individual BMDCs. Dotted histograms represent cells stained with isotype-matched control mAbs. The data shown is representative of three independent experiments.

Mentions: To determine a potential role of DCs in mediating protein- and polysaccharide-specific Ig isotype responses to S. pneumoniae we prepared a relatively pure population of DCs by culturing preselected BM cells in GM-CSF. After 6–8 d of culture we obtained a ≥95% population of cells with a morphology (data not shown) and cell surface phenotype (Fig. 1 C) consistent with immature myeloid (CD11c+, CD11b+, CD8α−) DCs (28). We first wished to determine the average rate of DC uptake of CM-DiI–labeled S. pneumoniae as a function of bacterial density. As is shown in Fig. 1 A, uptake of nonopsonized S. pneumoniae (nonencapsulated variant of capsular type 3, JD6/11) by cultured BMDCs was essentially nonsaturable. Similar kinetics of uptake as a function of bacterial density were also obtained with encapsulated (type 3 or type 14) or nonencapsulated (type 2) strains (data not shown). At the higher bacterial densities a plateau in uptake was observed after a prolonged culture period (>24 h) (Fig. 1 A), most likely due to the decrease in uptake of bacteria that is typically associated with DC maturation (Fig. 1 C).


Dendritic cells pulsed with intact Streptococcus pneumoniae elicit both protein- and polysaccharide-specific immunoglobulin isotype responses in vivo through distinct mechanisms.

Colino J, Shen Y, Snapper CM - J. Exp. Med. (2002)

S. pneumoniae uptake and BMDC responses to S. pneumoniae in vitro. (A) Time course of internalization of heat-killed S. pneumoniae (JD6/11 strain) labeled with the fluorescent tracer CM-DiI, at the bacteria: BMDC ratios indicated. The dotted line shows the estimated MFI produced by internalization of one diplococcus. (B) Concentrations of cytokine released into the media (left) or cytokine mRNA synthesis (middle) at varying times after addition of S. pneumoniae type 14, or during a 20-h period in the absence of bacteria after exposure to free bacteria for different times (right). (C) S. pneumoniae triggering of BMDC maturation. FACS® analysis of BMDC phenotype after culture for 20 h in the absence (−) or in the presence (+) of 800 heat-killed S. pneumoniae per individual BMDCs. Dotted histograms represent cells stained with isotype-matched control mAbs. The data shown is representative of three independent experiments.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2196017&req=5

fig1: S. pneumoniae uptake and BMDC responses to S. pneumoniae in vitro. (A) Time course of internalization of heat-killed S. pneumoniae (JD6/11 strain) labeled with the fluorescent tracer CM-DiI, at the bacteria: BMDC ratios indicated. The dotted line shows the estimated MFI produced by internalization of one diplococcus. (B) Concentrations of cytokine released into the media (left) or cytokine mRNA synthesis (middle) at varying times after addition of S. pneumoniae type 14, or during a 20-h period in the absence of bacteria after exposure to free bacteria for different times (right). (C) S. pneumoniae triggering of BMDC maturation. FACS® analysis of BMDC phenotype after culture for 20 h in the absence (−) or in the presence (+) of 800 heat-killed S. pneumoniae per individual BMDCs. Dotted histograms represent cells stained with isotype-matched control mAbs. The data shown is representative of three independent experiments.
Mentions: To determine a potential role of DCs in mediating protein- and polysaccharide-specific Ig isotype responses to S. pneumoniae we prepared a relatively pure population of DCs by culturing preselected BM cells in GM-CSF. After 6–8 d of culture we obtained a ≥95% population of cells with a morphology (data not shown) and cell surface phenotype (Fig. 1 C) consistent with immature myeloid (CD11c+, CD11b+, CD8α−) DCs (28). We first wished to determine the average rate of DC uptake of CM-DiI–labeled S. pneumoniae as a function of bacterial density. As is shown in Fig. 1 A, uptake of nonopsonized S. pneumoniae (nonencapsulated variant of capsular type 3, JD6/11) by cultured BMDCs was essentially nonsaturable. Similar kinetics of uptake as a function of bacterial density were also obtained with encapsulated (type 3 or type 14) or nonencapsulated (type 2) strains (data not shown). At the higher bacterial densities a plateau in uptake was observed after a prolonged culture period (>24 h) (Fig. 1 A), most likely due to the decrease in uptake of bacteria that is typically associated with DC maturation (Fig. 1 C).

Bottom Line: Immature bone marrow-derived myeloid dendritic cells (BMDCs) are induced to undergo phenotypic maturation and secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-12, and IL-10 when pulsed in vitro with intact Streptococcus pneumoniae.After transfer to naive mice, pulsed BMDCs induce immunoglobulin (Ig) isotype responses specific for both protein and polysaccharide pneumococcal antigens, having in common the requirement for viable BMDCs, T cells, and B7-dependent costimulation in the recipient mice.Whereas primary Ig isotype responses to bacterial proteins uniformly require BMDC expression of major histocompatibility complex class II, CD40, and B7, and the secretion of IL-6, but not IL-12, similar requirements for antipolysaccharide Ig responses were only observed for the IgG1 isotype.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.

ABSTRACT
Immature bone marrow-derived myeloid dendritic cells (BMDCs) are induced to undergo phenotypic maturation and secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-12, and IL-10 when pulsed in vitro with intact Streptococcus pneumoniae. After transfer to naive mice, pulsed BMDCs induce immunoglobulin (Ig) isotype responses specific for both protein and polysaccharide pneumococcal antigens, having in common the requirement for viable BMDCs, T cells, and B7-dependent costimulation in the recipient mice. Whereas primary Ig isotype responses to bacterial proteins uniformly require BMDC expression of major histocompatibility complex class II, CD40, and B7, and the secretion of IL-6, but not IL-12, similar requirements for antipolysaccharide Ig responses were only observed for the IgG1 isotype.

Show MeSH
Related in: MedlinePlus