title: 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.
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.
authors.affiliation: UMR-MD3-University Montpellier 1, Comparative Molecular Immuno-Physiopathology Lab, Faculté de Pharmacie, 34093 Montpellier, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Marsac
authors.forename: Stephanie
authors.initials: S
authors.lastname: García
authors.forename: Alexandra
authors.initials: A
authors.lastname: Fournet
authors.forename: Adam
authors.initials: A
authors.lastname: Aguirre
authors.forename: Karla
authors.initials: K
authors.lastname: Pino
authors.forename: Marcela
authors.initials: M
authors.lastname: Ferres
authors.forename: Alexis M
authors.initials: AM
authors.lastname: Kalergis
authors.forename: Marcelo
authors.initials: M
authors.lastname: Lopez-Lastra
authors.forename: Francisco
authors.initials: F
authors.lastname: Veas
mesh_terms: D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D003713:Dendritic Cells / Q000276:immunology* / Q000821:virology*; D042783:Endothelial Cells / Q000378:metabolism*; D006476:Orthohantavirus / Q000276:immunology* / Q000472:pathogenicity*; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D020780:Matrix Metalloproteinase 9