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Differential expression of Toll-like receptors in dendritic cells of patients with dengue during early and late acute phases of the disease.

Torres S, Hernández JC, Giraldo D, Arboleda M, Rojas M, Smit JM, Urcuqui-Inchima S - PLoS Negl Trop Dis (2013)

Bottom Line: In addition, we found a lower expression of TLR2 in patients with DF compared to DHF.This suggests that the virus can affect the interferon response through this signaling pathway.Changes in TLRs expression could play a central role in DC activation, thereby influencing the innate immune response.

View Article: PubMed Central - PubMed

Affiliation: Grupo Inmunovirología, Sede de Investigación Universitaria, Universidad de Antioquia, Medellín, Colombia.

ABSTRACT

Background: Dengue hemorrhagic fever (DHF) is observed in individuals that have pre-existing heterotypic dengue antibodies and is associated with increased viral load and high levels of pro-inflammatory cytokines early in infection. Interestingly, a recent study showed that dengue virus infection in the presence of antibodies resulted in poor stimulation of Toll-like receptors (TLRs), thereby facilitating virus particle production, and also suggesting that TLRs may contribute to disease pathogenesis.

Methodology/principal findings: We evaluated the expression levels of TLR2, 3, 4 and 9 and the co-stimulatory molecules CD80 and CD86 by flow cytometry. This was evaluated in monocytes, in myeloid and plasmacytoid dendritic cells (mDCs and pDCs) from 30 dengue patients with different clinical outcomes and in 20 healthy controls. Increased expression of TLR3 and TLR9 in DCs of patients with dengue fever (DF) early in infection was detected. In DCs from patients with severe manifestations, poor stimulation of TLR3 and TLR9 was observed. In addition, we found a lower expression of TLR2 in patients with DF compared to DHF. Expression levels of TLR4 were not affected. Furthermore, the expression of CD80 and CD86 was altered in mDCs and CD86 in pDCs of severe dengue cases. We show that interferon alpha production decreased in the presence of dengue virus after stimulation of PBMCs with the TLR9 agonist (CpG A). This suggests that the virus can affect the interferon response through this signaling pathway.

Conclusions/significance: These results show that during dengue disease progression, the expression profile of TLRs changes depending on the severity of the disease. Changes in TLRs expression could play a central role in DC activation, thereby influencing the innate immune response.

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Related in: MedlinePlus

TLR3 and TLR9 in mDCs and TLR9 in pDCs have different expression levels depending on disease severity.Expression profile of TLR2 and TLR9 in mDCs (A and B) and pDCs (C) of dengue patients isolated at different times after the onset of disease symptoms (day 3, 5 and 15) (n = 30) and of healthy controls (n = 20). The evaluation of TLR expression was performed by flow cytometry based on mean fluorescence intensity (MFI) analysis. Data are presented as the median and 25–75 interquartile ranges Statistical analysis was performed by using the Kruskal-Wallis test followed by the Dunn's Multiple comparisons Test. *p<0.05, ** p<0.01 and ***p<0.001.
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pntd-0002060-g005: TLR3 and TLR9 in mDCs and TLR9 in pDCs have different expression levels depending on disease severity.Expression profile of TLR2 and TLR9 in mDCs (A and B) and pDCs (C) of dengue patients isolated at different times after the onset of disease symptoms (day 3, 5 and 15) (n = 30) and of healthy controls (n = 20). The evaluation of TLR expression was performed by flow cytometry based on mean fluorescence intensity (MFI) analysis. Data are presented as the median and 25–75 interquartile ranges Statistical analysis was performed by using the Kruskal-Wallis test followed by the Dunn's Multiple comparisons Test. *p<0.05, ** p<0.01 and ***p<0.001.

Mentions: The effect of DENV on intracellular TLR expression was evaluated in cell lines and in animal models [32], [33]; however, the effect of DENV infection on the modulation of intracellular TLR expression in DCs of patients with DF or DHF has not been reported. The results show that on day 5 after the beginning of symptoms, mDCs of DF patients had a higher MFI for TLR3 and TLR9 than mDCs of DHF patients (p<0.05) and HCs (p<0.001 and p<0.01), respectively; Fig. 5A and B). On day 3 of illness, mDCs from DF or DHF showed a higher MFI for TLR3 and TLR9 compared to those of HCs (Fig. 5A). In the convalescent phase, the expression levels of TLR3 and TLR9 decreased to similar levels as in HCs. The MFI results for TLR9 in pDCs of DF patients showed higher expression levels on day 3 of illness compared to those of DHF patients (p<0.05; Fig. 5A). Taken together, our results are consistent with recently published in vitro data [13], [32], [33] and suggest that the increase in TLR3 and TLR9 expression in DF patients could act as an antiviral factor.


Differential expression of Toll-like receptors in dendritic cells of patients with dengue during early and late acute phases of the disease.

Torres S, Hernández JC, Giraldo D, Arboleda M, Rojas M, Smit JM, Urcuqui-Inchima S - PLoS Negl Trop Dis (2013)

TLR3 and TLR9 in mDCs and TLR9 in pDCs have different expression levels depending on disease severity.Expression profile of TLR2 and TLR9 in mDCs (A and B) and pDCs (C) of dengue patients isolated at different times after the onset of disease symptoms (day 3, 5 and 15) (n = 30) and of healthy controls (n = 20). The evaluation of TLR expression was performed by flow cytometry based on mean fluorescence intensity (MFI) analysis. Data are presented as the median and 25–75 interquartile ranges Statistical analysis was performed by using the Kruskal-Wallis test followed by the Dunn's Multiple comparisons Test. *p<0.05, ** p<0.01 and ***p<0.001.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3585035&req=5

pntd-0002060-g005: TLR3 and TLR9 in mDCs and TLR9 in pDCs have different expression levels depending on disease severity.Expression profile of TLR2 and TLR9 in mDCs (A and B) and pDCs (C) of dengue patients isolated at different times after the onset of disease symptoms (day 3, 5 and 15) (n = 30) and of healthy controls (n = 20). The evaluation of TLR expression was performed by flow cytometry based on mean fluorescence intensity (MFI) analysis. Data are presented as the median and 25–75 interquartile ranges Statistical analysis was performed by using the Kruskal-Wallis test followed by the Dunn's Multiple comparisons Test. *p<0.05, ** p<0.01 and ***p<0.001.
Mentions: The effect of DENV on intracellular TLR expression was evaluated in cell lines and in animal models [32], [33]; however, the effect of DENV infection on the modulation of intracellular TLR expression in DCs of patients with DF or DHF has not been reported. The results show that on day 5 after the beginning of symptoms, mDCs of DF patients had a higher MFI for TLR3 and TLR9 than mDCs of DHF patients (p<0.05) and HCs (p<0.001 and p<0.01), respectively; Fig. 5A and B). On day 3 of illness, mDCs from DF or DHF showed a higher MFI for TLR3 and TLR9 compared to those of HCs (Fig. 5A). In the convalescent phase, the expression levels of TLR3 and TLR9 decreased to similar levels as in HCs. The MFI results for TLR9 in pDCs of DF patients showed higher expression levels on day 3 of illness compared to those of DHF patients (p<0.05; Fig. 5A). Taken together, our results are consistent with recently published in vitro data [13], [32], [33] and suggest that the increase in TLR3 and TLR9 expression in DF patients could act as an antiviral factor.

Bottom Line: In addition, we found a lower expression of TLR2 in patients with DF compared to DHF.This suggests that the virus can affect the interferon response through this signaling pathway.Changes in TLRs expression could play a central role in DC activation, thereby influencing the innate immune response.

View Article: PubMed Central - PubMed

Affiliation: Grupo Inmunovirología, Sede de Investigación Universitaria, Universidad de Antioquia, Medellín, Colombia.

ABSTRACT

Background: Dengue hemorrhagic fever (DHF) is observed in individuals that have pre-existing heterotypic dengue antibodies and is associated with increased viral load and high levels of pro-inflammatory cytokines early in infection. Interestingly, a recent study showed that dengue virus infection in the presence of antibodies resulted in poor stimulation of Toll-like receptors (TLRs), thereby facilitating virus particle production, and also suggesting that TLRs may contribute to disease pathogenesis.

Methodology/principal findings: We evaluated the expression levels of TLR2, 3, 4 and 9 and the co-stimulatory molecules CD80 and CD86 by flow cytometry. This was evaluated in monocytes, in myeloid and plasmacytoid dendritic cells (mDCs and pDCs) from 30 dengue patients with different clinical outcomes and in 20 healthy controls. Increased expression of TLR3 and TLR9 in DCs of patients with dengue fever (DF) early in infection was detected. In DCs from patients with severe manifestations, poor stimulation of TLR3 and TLR9 was observed. In addition, we found a lower expression of TLR2 in patients with DF compared to DHF. Expression levels of TLR4 were not affected. Furthermore, the expression of CD80 and CD86 was altered in mDCs and CD86 in pDCs of severe dengue cases. We show that interferon alpha production decreased in the presence of dengue virus after stimulation of PBMCs with the TLR9 agonist (CpG A). This suggests that the virus can affect the interferon response through this signaling pathway.

Conclusions/significance: These results show that during dengue disease progression, the expression profile of TLRs changes depending on the severity of the disease. Changes in TLRs expression could play a central role in DC activation, thereby influencing the innate immune response.

Show MeSH
Related in: MedlinePlus