Limits...
Infection of human monocyte-derived dendritic cells by ANDES Hantavirus enhances pro-inflammatory state, the secretion of active MMP-9 and indirectly enhances endothelial permeability.

Marsac D, García S, Fournet A, Aguirre A, Pino K, Ferres M, Kalergis AM, Lopez-Lastra M, Veas F - Virol. J. (2011)

Bottom Line: Currently, neither specific therapy nor vaccines are available against this pathogen.Moreover, this infection induces an enhanced expression of soluble pro-inflammatory factors, including TNF-α and the active gMMP-9, as well as a decreased expression of anti-inflammatory cytokines, such as IL-10 and TGF-β.Primary human DCs, that are primarily targeted by hantaviruses can productively be infected by ANDV and subsequently induce direct effects favoring a proinflammatory phenotype of infected DCs.

View Article: PubMed Central - HTML - PubMed

Affiliation: UMR-MD3-University Montpellier 1, Comparative Molecular Immuno-Physiopathology Lab, Faculté de Pharmacie, 34093 Montpellier, France.

ABSTRACT

Background: Andes virus (ANDV), a rodent-borne Hantavirus, is the major etiological agent of Hantavirus cardiopulmonary syndrome (HCPS) in South America, which is mainly characterized by a vascular leakage with high rate of fatal outcomes for infected patients. Currently, neither specific therapy nor vaccines are available against this pathogen. ANDV infects both dendritic and epithelial cells, but in despite that the severity of the disease directly correlates with the viral RNA load, considerable evidence suggests that immune mechanisms rather than direct viral cytopathology are responsible for plasma leakage in HCPS. Here, we assessed the possible effect of soluble factors, induced in viral-activated DCs, on endothelial permeability. Activated immune cells, including DC, secrete gelatinolytic matrix metalloproteases (gMMP-2 and -9) that modulate the vascular permeability for their trafficking.

Methods: A clinical ANDES isolate was used to infect DC derived from primary PBMC. Maturation and pro-inflammatory phenotypes of ANDES-infected DC were assessed by studying the expression of receptors, cytokines and active gMMP-9, as well as some of their functional status. The ANDES-infected DC supernatants were assessed for their capacity to enhance a monolayer endothelial permeability using primary human vascular endothelial cells (HUVEC).

Results: Here, we show that in vitro primary DCs infected by a clinical isolate of ANDV shed virus RNA and proteins, suggesting a competent viral replication in these cells. Moreover, this infection induces an enhanced expression of soluble pro-inflammatory factors, including TNF-α and the active gMMP-9, as well as a decreased expression of anti-inflammatory cytokines, such as IL-10 and TGF-β. These viral activated cells are less sensitive to apoptosis. Moreover, supernatants from ANDV-infected DCs were able to indirectly enhance the permeability of a monolayer of primary HUVEC.

Conclusions: Primary human DCs, that are primarily targeted by hantaviruses can productively be infected by ANDV and subsequently induce direct effects favoring a proinflammatory phenotype of infected DCs. Finally, based on our observations, we hypothesize that soluble factors secreted in ANDV-infected DC supernatants, importantly contribute to the endothelial permeability enhancement that characterize the HCPS.

Show MeSH

Related in: MedlinePlus

Inflammatory state of ANDV-infected iDCs. The level of TNF-α (A) IL-10 (B), and TGF-β (C) in supernatants of uninfected DCs (Mock), ANDV-infected iDCs (MOI = 1) (ANDV), or LPS-pulsed DCs, was assessed by ELISA respectively at 3 h (A) and 48 h (B and C) post-ANDV infection. In (B) and (C), bar graphs depict the fold-increase of cytokine production relatively to mock. Data are means of five to eight independent experiments *, p< 0.05; **, p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3104372&req=5

Figure 3: Inflammatory state of ANDV-infected iDCs. The level of TNF-α (A) IL-10 (B), and TGF-β (C) in supernatants of uninfected DCs (Mock), ANDV-infected iDCs (MOI = 1) (ANDV), or LPS-pulsed DCs, was assessed by ELISA respectively at 3 h (A) and 48 h (B and C) post-ANDV infection. In (B) and (C), bar graphs depict the fold-increase of cytokine production relatively to mock. Data are means of five to eight independent experiments *, p< 0.05; **, p < 0.01.

Mentions: The presence of high levels of pro-inflammatory cytokines both in plasma and lungs have been reported as pathological markers associated with HCPS in humans. These excesses of pro-inflammatory cytokines are secreted in patients by both hantavirus-activated macrophages and specific T cells [28]. Particularly, the levels of the pro-inflammatory cytokine TNF-α in HCPS patient sera are the dramatically elevated [29,30]. Infection of iDCs by other Hantaviruses induces the production of pro-inflammatory cytokines as well [7]. Therefore, we sought to evaluate whether ANDV infection induces a similar DC phenotype. Supernatants of Mock-DCs, ANDV-infected DCs (3 h post-viral infection), and LPS-pulsed DCs were assessed for the production of the pro-inflammatory cytokine, TNF-α. In agreement with what has been described for other Hantaviruses, supernatants harvested from ANDV-infected DCs display a significant increase in TNF-α as compared with supernatants from uninfected iDCs (Figure 3A). In a similar experimental setting, we also evaluated the expression of IL-10 and TGF-β, two anti-inflammatory cytokines [31]. Interestingly, in supernatants harvested from ANDV-infected DCs, IL-10 levels were weakly altered as compared with uninfected DCs, while TGF-β levels decrease was more pronounced (Figure 3B and 3C). Thus, our observations suggest that ANDV-infected DCs exhibit a pro-inflammatory cytokine profile.


Infection of human monocyte-derived dendritic cells by ANDES Hantavirus enhances pro-inflammatory state, the secretion of active MMP-9 and indirectly enhances endothelial permeability.

Marsac D, García S, Fournet A, Aguirre A, Pino K, Ferres M, Kalergis AM, Lopez-Lastra M, Veas F - Virol. J. (2011)

Inflammatory state of ANDV-infected iDCs. The level of TNF-α (A) IL-10 (B), and TGF-β (C) in supernatants of uninfected DCs (Mock), ANDV-infected iDCs (MOI = 1) (ANDV), or LPS-pulsed DCs, was assessed by ELISA respectively at 3 h (A) and 48 h (B and C) post-ANDV infection. In (B) and (C), bar graphs depict the fold-increase of cytokine production relatively to mock. Data are means of five to eight independent experiments *, p< 0.05; **, p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104372&req=5

Figure 3: Inflammatory state of ANDV-infected iDCs. The level of TNF-α (A) IL-10 (B), and TGF-β (C) in supernatants of uninfected DCs (Mock), ANDV-infected iDCs (MOI = 1) (ANDV), or LPS-pulsed DCs, was assessed by ELISA respectively at 3 h (A) and 48 h (B and C) post-ANDV infection. In (B) and (C), bar graphs depict the fold-increase of cytokine production relatively to mock. Data are means of five to eight independent experiments *, p< 0.05; **, p < 0.01.
Mentions: The presence of high levels of pro-inflammatory cytokines both in plasma and lungs have been reported as pathological markers associated with HCPS in humans. These excesses of pro-inflammatory cytokines are secreted in patients by both hantavirus-activated macrophages and specific T cells [28]. Particularly, the levels of the pro-inflammatory cytokine TNF-α in HCPS patient sera are the dramatically elevated [29,30]. Infection of iDCs by other Hantaviruses induces the production of pro-inflammatory cytokines as well [7]. Therefore, we sought to evaluate whether ANDV infection induces a similar DC phenotype. Supernatants of Mock-DCs, ANDV-infected DCs (3 h post-viral infection), and LPS-pulsed DCs were assessed for the production of the pro-inflammatory cytokine, TNF-α. In agreement with what has been described for other Hantaviruses, supernatants harvested from ANDV-infected DCs display a significant increase in TNF-α as compared with supernatants from uninfected iDCs (Figure 3A). In a similar experimental setting, we also evaluated the expression of IL-10 and TGF-β, two anti-inflammatory cytokines [31]. Interestingly, in supernatants harvested from ANDV-infected DCs, IL-10 levels were weakly altered as compared with uninfected DCs, while TGF-β levels decrease was more pronounced (Figure 3B and 3C). Thus, our observations suggest that ANDV-infected DCs exhibit a pro-inflammatory cytokine profile.

Bottom Line: Currently, neither specific therapy nor vaccines are available against this pathogen.Moreover, this infection induces an enhanced expression of soluble pro-inflammatory factors, including TNF-α and the active gMMP-9, as well as a decreased expression of anti-inflammatory cytokines, such as IL-10 and TGF-β.Primary human DCs, that are primarily targeted by hantaviruses can productively be infected by ANDV and subsequently induce direct effects favoring a proinflammatory phenotype of infected DCs.

View Article: PubMed Central - HTML - PubMed

Affiliation: UMR-MD3-University Montpellier 1, Comparative Molecular Immuno-Physiopathology Lab, Faculté de Pharmacie, 34093 Montpellier, France.

ABSTRACT

Background: Andes virus (ANDV), a rodent-borne Hantavirus, is the major etiological agent of Hantavirus cardiopulmonary syndrome (HCPS) in South America, which is mainly characterized by a vascular leakage with high rate of fatal outcomes for infected patients. Currently, neither specific therapy nor vaccines are available against this pathogen. ANDV infects both dendritic and epithelial cells, but in despite that the severity of the disease directly correlates with the viral RNA load, considerable evidence suggests that immune mechanisms rather than direct viral cytopathology are responsible for plasma leakage in HCPS. Here, we assessed the possible effect of soluble factors, induced in viral-activated DCs, on endothelial permeability. Activated immune cells, including DC, secrete gelatinolytic matrix metalloproteases (gMMP-2 and -9) that modulate the vascular permeability for their trafficking.

Methods: A clinical ANDES isolate was used to infect DC derived from primary PBMC. Maturation and pro-inflammatory phenotypes of ANDES-infected DC were assessed by studying the expression of receptors, cytokines and active gMMP-9, as well as some of their functional status. The ANDES-infected DC supernatants were assessed for their capacity to enhance a monolayer endothelial permeability using primary human vascular endothelial cells (HUVEC).

Results: Here, we show that in vitro primary DCs infected by a clinical isolate of ANDV shed virus RNA and proteins, suggesting a competent viral replication in these cells. Moreover, this infection induces an enhanced expression of soluble pro-inflammatory factors, including TNF-α and the active gMMP-9, as well as a decreased expression of anti-inflammatory cytokines, such as IL-10 and TGF-β. These viral activated cells are less sensitive to apoptosis. Moreover, supernatants from ANDV-infected DCs were able to indirectly enhance the permeability of a monolayer of primary HUVEC.

Conclusions: Primary human DCs, that are primarily targeted by hantaviruses can productively be infected by ANDV and subsequently induce direct effects favoring a proinflammatory phenotype of infected DCs. Finally, based on our observations, we hypothesize that soluble factors secreted in ANDV-infected DC supernatants, importantly contribute to the endothelial permeability enhancement that characterize the HCPS.

Show MeSH
Related in: MedlinePlus