Ebola virus causes severe hemorrhagic fever with high mortality rates in humans and nonhuman primates. Vascular instability and dysregulation are disease-decisive symptoms during severe infection. While the transmembrane glycoprotein GP(1,2) has been shown to cause endothelial cell destruction, the role of the soluble glycoproteins in pathogenesis is largely unknown; however, they are hypothesized to be of biological relevance in terms of target cell activation and/or increase of endothelial permeability. Here we show that virus-like particles (VLPs) consisting of the Ebola virus matrix protein VP40 and GP(1,2) were able to activate endothelial cells and induce a decrease in barrier function as determined by impedance spectroscopy and hydraulic conductivity measurements. In contrast, the soluble glycoproteins sGP and delta-peptide did not activate endothelial cells or change the endothelial barrier function. The VLP-induced decrease in barrier function was further enhanced by the cytokine tumor necrosis factor alpha (TNF-alpha), which is known to induce a long-lasting decrease in endothelial cell barrier function and is hypothesized to play a key role in Ebola virus pathogenesis. Surprisingly, sGP, but not delta-peptide, induced a recovery of endothelial barrier function following treatment with TNF-alpha. Our results demonstrate that Ebola virus GP(1,2) in its particle-associated form mediates endothelial cell activation and a decrease in endothelial cell barrier function. Furthermore, sGP, the major soluble glycoprotein of Ebola virus, seems to possess an anti-inflammatory role by protecting the endothelial cell barrier function.