Towards an in vitro model for acute hemorrhagic conjunctivitis: cytokine-mediated vascular endothelial cell activation triggered by enterovirus type 70 infection.
BACKGROUND
Little is known of the pathogenetic mechanisms of enterovirus type 70 (EV70), a causative agent of acute hemorrhagic conjunctivitis. However, virus- or cytokine-induced perturbation of vascular endothelial cells are potential triggering events.


OBJECTIVE
To determine whether EV70 infection of human umbilical vascular endothelial cells (HUVECs) and human corneal epithelial cells (HCEs) causes the release of vasoactive cytokines, capable of triggering vascular endothelial cell activation.


METHODS
Susceptibility of cultured HUVECs and HCEs to EV70 was tested by observing the appearance of cytopathic effect or immunoprecipitation of viral protein in infected cells. The culture fluids from the virus-infected cells were tested for their ability to stimulate the expression of intercellular adhesion molecule-1 (ICAM-1) on uninfected HUVECs. Anti-cytokine antibodies were used to identify ICAM-1-activating cytokine(s).


RESULTS
Both HUVECs and HCEs were susceptible to EV70 infection. Culture fluids from EV70-infected HUVECs and HCEs stimulated ICAM-l expression on uninfected HUVECs, which was completely blocked by anti-interleukin-1alpha (IL-1alpha) antibody but not by interleukin-1beta (IL-1beta) or anti-tumor necrosis factor alpha (TNFalpha) antibodies.


CONCLUSIONS
This study provides the first evidence of EV70 infection of both HCEs and HUVECs, and furthermore, identifies IL-1alpha as the predominant endothelial cell-activating factor produced by EV70-infected cells. Since endothelial cell activation is often an initiating step towards vascular permeability and/or inflammation, the perturbation of endothelial cell function through EV70 induced IL-1alpha is thus a potential contributory factor in the pathogenesis of EV70-associated hemorrhagic conjunctivitis.
Chang
Cheng-Hsien
CH
Department of Ophthalmology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Lin
Kuei-Hsiang
KH
Anderson
Robert
R
D000906:Antibodies; D002199:Capillary Permeability; D002478:Cells, Cultured; D003232:Conjunctivitis, Acute Hemorrhagic / Q000276:immunology / Q000821:virology*; D003588:Cytopathogenic Effect, Viral; D042783:Endothelial Cells / Q000276:immunology* / Q000821:virology*; D030016:Enterovirus D, Human / Q000254:growth & development / Q000472:pathogenicity*; D004847:Epithelial Cells / Q000276:immunology / Q000821:virology; D019573:Epithelium, Corneal / Q000276:immunology / Q000821:virology*; D005786:Gene Expression Regulation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D007375:Interleukin-1 / Q000276:immunology* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D000906:Antibodies; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1