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Induction of IL-12 production in human peripheral monocytes by Trypanosoma cruzi Is mediated by glycosylphosphatidylinositol-anchored mucin-like glycoproteins and potentiated by IFN- γ and CD40-CD40L interactions.

Abel LC, Ferreira LR, Cunha Navarro I, Baron MA, Kalil J, Gazzinelli RT, Rizzo LV, Cunha-Neto E - Mediators Inflamm. (2014)

Bottom Line: It has been extensively described that T. cruzi or its products-like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins)-are potent inducers of proinflammatory responses (i.e., cytokines and NO production) by IFN-γ primed murine macrophages.However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells.We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, Heart Institute (InCor), School of Medicine, University of São Paulo, 05403-001 São Paulo, SP, Brazil.

ABSTRACT
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), is characterized by immunopathology driven by IFN-γ secreting Th1-like T cells. T. cruzi has a thick coat of mucin-like glycoproteins covering its surface, which plays an important role in parasite invasion and host immunomodulation. It has been extensively described that T. cruzi or its products-like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins)-are potent inducers of proinflammatory responses (i.e., cytokines and NO production) by IFN-γ primed murine macrophages. However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells. We therefore decided to further investigate the in vitro cytokine production profile from human mononuclear cells from uninfected donors exposed to T. cruzi as well as tGPI-mucins. We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ. Our findings suggest that the polarized T1-type cytokine profile seen in T. cruzi infected patients might be a long-term effect of IL-12 production induced by lifelong exposure to T. cruzi tGPI-mucins.

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Potentiation of IL-12 production induced by (a) live T. cruzi trypomastigotes or (b) tGPI-mucins is dependent on IFN-γ and CD40. Irradiated PBMC were incubated with T cell lines, PHA (5 ug/mL), and different blocking antibodies (anti-IFN-γ, anti-CD40, anti-CD28, and anti-IFN/CD40/CD28). Results come from 4 distinct experiments. Groups were compared by a nonparametrical test (Mann-Whitney Rank Sum Test) with GraphPad InStat software (version 5.0; GraphPad). Results were expressed as medians and interquartile ranges. P values were considered significant if <0.05. Significance bars are shown in comparison with trypo + PHA or tGPI-mucin + PHA.
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fig4: Potentiation of IL-12 production induced by (a) live T. cruzi trypomastigotes or (b) tGPI-mucins is dependent on IFN-γ and CD40. Irradiated PBMC were incubated with T cell lines, PHA (5 ug/mL), and different blocking antibodies (anti-IFN-γ, anti-CD40, anti-CD28, and anti-IFN/CD40/CD28). Results come from 4 distinct experiments. Groups were compared by a nonparametrical test (Mann-Whitney Rank Sum Test) with GraphPad InStat software (version 5.0; GraphPad). Results were expressed as medians and interquartile ranges. P values were considered significant if <0.05. Significance bars are shown in comparison with trypo + PHA or tGPI-mucin + PHA.

Mentions: In an attempt to study the mechanisms underlying T. cruzi-induced potentiation of IL-12 production by human monocytes, we cocultured these cells with PHA-activated T cell lines, 5 × 104 T. cruzi Y strain living trypomastigotes, or tGPI-mucins and added neutralizing/blocking antibodies to human IFN-γ, CD40, and CD28. Results indicated that blocking IFN-γ or CD40 individually caused approximately 50% and 35% of inhibition of IL-12 production, respectively, while anti-CD28 showed negligible inhibition. The combined effect of the three antibodies induced 85% of inhibition, suggesting that most of the IL-12-inducing effects of PHA-activated T cell lines are due to IFN-γ production and CD40-CD40L interactions (Figure 4(a)). Similar results were obtained when tGPI mucin was used as stimulus (Figure 4(b)) suggesting that these molecules may be the effectors in the T. cruzi-induced IL-12 production in humans, as has been previously described in mice [8].


Induction of IL-12 production in human peripheral monocytes by Trypanosoma cruzi Is mediated by glycosylphosphatidylinositol-anchored mucin-like glycoproteins and potentiated by IFN- γ and CD40-CD40L interactions.

Abel LC, Ferreira LR, Cunha Navarro I, Baron MA, Kalil J, Gazzinelli RT, Rizzo LV, Cunha-Neto E - Mediators Inflamm. (2014)

Potentiation of IL-12 production induced by (a) live T. cruzi trypomastigotes or (b) tGPI-mucins is dependent on IFN-γ and CD40. Irradiated PBMC were incubated with T cell lines, PHA (5 ug/mL), and different blocking antibodies (anti-IFN-γ, anti-CD40, anti-CD28, and anti-IFN/CD40/CD28). Results come from 4 distinct experiments. Groups were compared by a nonparametrical test (Mann-Whitney Rank Sum Test) with GraphPad InStat software (version 5.0; GraphPad). Results were expressed as medians and interquartile ranges. P values were considered significant if <0.05. Significance bars are shown in comparison with trypo + PHA or tGPI-mucin + PHA.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4120781&req=5

fig4: Potentiation of IL-12 production induced by (a) live T. cruzi trypomastigotes or (b) tGPI-mucins is dependent on IFN-γ and CD40. Irradiated PBMC were incubated with T cell lines, PHA (5 ug/mL), and different blocking antibodies (anti-IFN-γ, anti-CD40, anti-CD28, and anti-IFN/CD40/CD28). Results come from 4 distinct experiments. Groups were compared by a nonparametrical test (Mann-Whitney Rank Sum Test) with GraphPad InStat software (version 5.0; GraphPad). Results were expressed as medians and interquartile ranges. P values were considered significant if <0.05. Significance bars are shown in comparison with trypo + PHA or tGPI-mucin + PHA.
Mentions: In an attempt to study the mechanisms underlying T. cruzi-induced potentiation of IL-12 production by human monocytes, we cocultured these cells with PHA-activated T cell lines, 5 × 104 T. cruzi Y strain living trypomastigotes, or tGPI-mucins and added neutralizing/blocking antibodies to human IFN-γ, CD40, and CD28. Results indicated that blocking IFN-γ or CD40 individually caused approximately 50% and 35% of inhibition of IL-12 production, respectively, while anti-CD28 showed negligible inhibition. The combined effect of the three antibodies induced 85% of inhibition, suggesting that most of the IL-12-inducing effects of PHA-activated T cell lines are due to IFN-γ production and CD40-CD40L interactions (Figure 4(a)). Similar results were obtained when tGPI mucin was used as stimulus (Figure 4(b)) suggesting that these molecules may be the effectors in the T. cruzi-induced IL-12 production in humans, as has been previously described in mice [8].

Bottom Line: It has been extensively described that T. cruzi or its products-like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins)-are potent inducers of proinflammatory responses (i.e., cytokines and NO production) by IFN-γ primed murine macrophages.However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells.We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunology, Heart Institute (InCor), School of Medicine, University of São Paulo, 05403-001 São Paulo, SP, Brazil.

ABSTRACT
Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), is characterized by immunopathology driven by IFN-γ secreting Th1-like T cells. T. cruzi has a thick coat of mucin-like glycoproteins covering its surface, which plays an important role in parasite invasion and host immunomodulation. It has been extensively described that T. cruzi or its products-like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins)-are potent inducers of proinflammatory responses (i.e., cytokines and NO production) by IFN-γ primed murine macrophages. However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells. We therefore decided to further investigate the in vitro cytokine production profile from human mononuclear cells from uninfected donors exposed to T. cruzi as well as tGPI-mucins. We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ. Our findings suggest that the polarized T1-type cytokine profile seen in T. cruzi infected patients might be a long-term effect of IL-12 production induced by lifelong exposure to T. cruzi tGPI-mucins.

Show MeSH
Related in: MedlinePlus