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Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults.

Szpakowski P, Biet F, Locht C, Paszkiewicz M, Rudnicka W, Druszczyńska M, Allain F, Fol M, Pestel J, Kowalewicz-Kulbat M - J Immunol Res (2015)

Bottom Line: We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective.In contrast, both BCG strains decreased the DC-SIGN expression on human DCs.The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, Banacha Street 12/19, 90-237 Lodz, Poland.

ABSTRACT
Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

No MeSH data available.


Related in: MedlinePlus

DC-SIGN surface expression of MoDCs. Human MoDCs were pulsed either with PPD (10 μg/mL), BCG (1 : 1), rBCGhIL-18 (1 : 1), or LPS (1 μg/mL) for 24 h or were left unstimulated (DC). (a) One representative experiment out of 20 independent ones is shown. Grey histograms represent the cell reactivity to fluorochrome-matched isotype control antibodies. The white histograms represent the reactivity with the anti-DC-SIGN antibody. The vertical broken lines represent the upregulation obtained by LPS stimulation; (b) percentage of positive cells with the DC-SIGN expression; (c) median fluorescence intensity (MFI) values (median ± SEM of 20 independent donors). Fluorescence intensity was calculated by the MFI of the receptor expression from which the MFI obtained with a nonrelevant, isotype-matched antibody was substracted. Statistical analyses were performed using the Kruskal-Wallis test. *P < 0.05; **P < 0.01.
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fig5: DC-SIGN surface expression of MoDCs. Human MoDCs were pulsed either with PPD (10 μg/mL), BCG (1 : 1), rBCGhIL-18 (1 : 1), or LPS (1 μg/mL) for 24 h or were left unstimulated (DC). (a) One representative experiment out of 20 independent ones is shown. Grey histograms represent the cell reactivity to fluorochrome-matched isotype control antibodies. The white histograms represent the reactivity with the anti-DC-SIGN antibody. The vertical broken lines represent the upregulation obtained by LPS stimulation; (b) percentage of positive cells with the DC-SIGN expression; (c) median fluorescence intensity (MFI) values (median ± SEM of 20 independent donors). Fluorescence intensity was calculated by the MFI of the receptor expression from which the MFI obtained with a nonrelevant, isotype-matched antibody was substracted. Statistical analyses were performed using the Kruskal-Wallis test. *P < 0.05; **P < 0.01.

Mentions: To investigate the effect of rBCGIL-18 on human monocyte-derived DC maturation, the DCs were pulsed with rBCGhIL-18, BCG, or PPD and compared to control conditions (i.e., unstimulated DCs as a negative control, and LPS-pulsed DCs as a positive control). Various T cell costimulation surface markers (CD86, CD80, and CD40), as well as HLA-DR expression, were assessed by flow cytometry. LPS induced the upregulation of CD86 (Figure 3(a)) and CD80 (Figure 4(a)) as well as CD40 and HLA-DR (data not shown), and the downregulation of DC-SIGN. DC incubation with PPD did not modify the expression of CD86, CD80, CD40, and HLA-DR, but downregulated the expression of DC-SIGN. In contrast, the incubation with either of the two BCG strains at an MOI of 1 : 1 induced the upregulation of some of these surface markers and again the downregulation of DC-SIGN. Moreover, we could detect a higher proportion of BCG- and rBCGhIL-18-stimulated MoDCs with CD86 expression, as compared to unstimulated DC, and those incubated with PPD (Figure 3(b)). This difference was not observed in the case of CD80 (Figure 4(b)), HLA-DR, CD40 markers (data not shown) and DC-SIGN (Figure 5(a)). When the median of 20 different donors was analyzed, a significant increase in CD86 expression was observed upon incubation with BCG or with rBCGhIL-18 compared with untreated DC and those incubated with PPD (Figure 3(c)). In parallel, a significant decrease in DC-SIGN expression was observed upon incubation with BCG, rBCGhIL-18, PPD or LPS, consistent with a DC maturation phenotype. However, there was no significant difference between BCG and rBCGhIL-18. (Figure 5(c)).


Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults.

Szpakowski P, Biet F, Locht C, Paszkiewicz M, Rudnicka W, Druszczyńska M, Allain F, Fol M, Pestel J, Kowalewicz-Kulbat M - J Immunol Res (2015)

DC-SIGN surface expression of MoDCs. Human MoDCs were pulsed either with PPD (10 μg/mL), BCG (1 : 1), rBCGhIL-18 (1 : 1), or LPS (1 μg/mL) for 24 h or were left unstimulated (DC). (a) One representative experiment out of 20 independent ones is shown. Grey histograms represent the cell reactivity to fluorochrome-matched isotype control antibodies. The white histograms represent the reactivity with the anti-DC-SIGN antibody. The vertical broken lines represent the upregulation obtained by LPS stimulation; (b) percentage of positive cells with the DC-SIGN expression; (c) median fluorescence intensity (MFI) values (median ± SEM of 20 independent donors). Fluorescence intensity was calculated by the MFI of the receptor expression from which the MFI obtained with a nonrelevant, isotype-matched antibody was substracted. Statistical analyses were performed using the Kruskal-Wallis test. *P < 0.05; **P < 0.01.
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Related In: Results  -  Collection

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fig5: DC-SIGN surface expression of MoDCs. Human MoDCs were pulsed either with PPD (10 μg/mL), BCG (1 : 1), rBCGhIL-18 (1 : 1), or LPS (1 μg/mL) for 24 h or were left unstimulated (DC). (a) One representative experiment out of 20 independent ones is shown. Grey histograms represent the cell reactivity to fluorochrome-matched isotype control antibodies. The white histograms represent the reactivity with the anti-DC-SIGN antibody. The vertical broken lines represent the upregulation obtained by LPS stimulation; (b) percentage of positive cells with the DC-SIGN expression; (c) median fluorescence intensity (MFI) values (median ± SEM of 20 independent donors). Fluorescence intensity was calculated by the MFI of the receptor expression from which the MFI obtained with a nonrelevant, isotype-matched antibody was substracted. Statistical analyses were performed using the Kruskal-Wallis test. *P < 0.05; **P < 0.01.
Mentions: To investigate the effect of rBCGIL-18 on human monocyte-derived DC maturation, the DCs were pulsed with rBCGhIL-18, BCG, or PPD and compared to control conditions (i.e., unstimulated DCs as a negative control, and LPS-pulsed DCs as a positive control). Various T cell costimulation surface markers (CD86, CD80, and CD40), as well as HLA-DR expression, were assessed by flow cytometry. LPS induced the upregulation of CD86 (Figure 3(a)) and CD80 (Figure 4(a)) as well as CD40 and HLA-DR (data not shown), and the downregulation of DC-SIGN. DC incubation with PPD did not modify the expression of CD86, CD80, CD40, and HLA-DR, but downregulated the expression of DC-SIGN. In contrast, the incubation with either of the two BCG strains at an MOI of 1 : 1 induced the upregulation of some of these surface markers and again the downregulation of DC-SIGN. Moreover, we could detect a higher proportion of BCG- and rBCGhIL-18-stimulated MoDCs with CD86 expression, as compared to unstimulated DC, and those incubated with PPD (Figure 3(b)). This difference was not observed in the case of CD80 (Figure 4(b)), HLA-DR, CD40 markers (data not shown) and DC-SIGN (Figure 5(a)). When the median of 20 different donors was analyzed, a significant increase in CD86 expression was observed upon incubation with BCG or with rBCGhIL-18 compared with untreated DC and those incubated with PPD (Figure 3(c)). In parallel, a significant decrease in DC-SIGN expression was observed upon incubation with BCG, rBCGhIL-18, PPD or LPS, consistent with a DC maturation phenotype. However, there was no significant difference between BCG and rBCGhIL-18. (Figure 5(c)).

Bottom Line: We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective.In contrast, both BCG strains decreased the DC-SIGN expression on human DCs.The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology and Infectious Biology, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, Banacha Street 12/19, 90-237 Lodz, Poland.

ABSTRACT
Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

No MeSH data available.


Related in: MedlinePlus