Pathogenic Hantaviruses Andes Virus and Hantaan Virus Induce Adherens Junction Disassembly by Directing Vascular Endothelial Cadherin Internalization in Human Endothelial Cells

Abstract

Hantaviruses infect endothelial cells and cause 2 vascular permeability-based diseases. Pathogenic hantaviruses enhance the permeability of endothelial cells in response to vascular endothelial growth factor (VEGF). However, the mechanism by which hantaviruses hyperpermeabilize endothelial cells has not been defined. The paracellular permeability of endothelial cells is uniquely determined by the homophilic assembly of vascular endothelial cadherin (VE-cadherin) within adherens junctions, which is regulated by VEGF receptor-2 (VEGFR2) responses. Here, we investigated VEGFR2 phosphorylation and the internalization of VE-cadherin within endothelial cells infected by pathogenic Andes virus (ANDV) and Hantaan virus (HTNV) and nonpathogenic Tula virus (TULV) hantaviruses. We found that VEGF addition to ANDV-and HTNV-infected endothelial cells results in the hyperphosphorylation of VEGFR2, while TULV infection failed to increase VEGFR2 phosphorylation. Concomitant with the VEGFR2 hyperphosphorylation, VE-cadherin was internalized to intracellular vesicles within ANDV-or HTNV-, but not TULV-, infected endothelial cells. Addition of angiopoietin-1 (Ang-1) or sphingosine-1-phosphate (S1P) to ANDV-or HTNV-infected cells blocked VEcadherin internalization in response to VEGF. These findings are consistent with the ability of Ang-1 and S1P to inhibit hantavirus-induced endothelial cell permeability. Our results suggest that pathogenic hantaviruses disrupt fluid barrier properties of endothelial cell adherens junctions by enhancing VEGFR2-VE-cadherin pathway responses which increase paracellular permeability. These results provide a pathway-specific mechanism for the enhanced permeability of hantavirus-infected endothelial cells and suggest that stabilizing VE-cadherin within adherens junctions is a primary target for regulating endothelial cell permeability during pathogenic hantavirus infection.

Andes Virus Infection of Lymphatic Endothelial Cells Causes Giant Cell and Enhanced Permeability Responses That Are Rapamycin and Vascular Endothelial Growth Factor C Sensitive

“…HPS patients are acutely hypoxic (36,39,59,62,79), suggesting a link between pulmonary edema during HPS and enhanced endothelial cell VEGF-A responses (12,15,16,38,57,64,76). In fact, both HTNV and ANDV enhance VEGF-A-directed permeability responses, and inhibitors that antagonize this pathway block the hyperpermeability of hantavirus-infected BECs (28,29,34,35,63). Collectively, these findings tie altered VEGF-A responses following hantavirus infection to edema observed in HPS and HFRS patients.…”

“…Andes virus (ANDV) causes HPS, resulting in acute pulmonary edema and respiratory insufficiency (12,14,18,22,36,47,53,59,62,86). The means by which hantaviruses cause vascular leakage and edema are likely to be multifactorial in nature, and mechanisms by which hantaviruses alter fluid barrier properties of the vasculature are still being discovered (28,29,34,35,37,45,63,70,74). Tissue and organ edema are prominent findings in hantavirus patients, and blood vessel ECs (BECs) form a primary fluid barrier that normally restricts fluid egress into tissues and permits blood and fluid recirculation (1,19,80).…”

“…Pathogenic hantaviruses bind and inactivate ␣ v ␤ 3 receptors on capillary endothelial cells (27,31,65), and days after infection, hantaviruses inhibit ␤ 3 integrin responses and cause BEC hyperpermeability in response to vascular endothelial growth factor A (VEGF-A) (28,29,34,35,56,65). VEGF-A was originally found as a vascular permeability factor that potently causes localized vascular leakage and edema (19)(20)(21).…”

The C-Terminal 42 Residues of the Tula Virus Gn Protein Regulate Interferon Induction

“…Integrin receptor regulation further distinguishes pathogenic from nonpathogenic hantaviruses and is associated with increased vascular permeability (9,10,16,39). Only pathogenic hantaviruses use ␣ v ␤ 3 integrin endothelial cell receptors, while TULV and PHV use ␣ 5 ␤ 1 integrins for cell entry (7,11,39).…”

“…Only pathogenic hantaviruses use ␣ v ␤ 3 integrin endothelial cell receptors, while TULV and PHV use ␣ 5 ␤ 1 integrins for cell entry (7,11,39). ␤ 3 Receptors on platelets and endothelial cells regulate fluid barrier functions of the vasculature as well as permeability induced by vascular endothelial growth factor (VEGF) (8,9,16). Pathogenic hantaviruses dysregulate normal ␣ v ␤ 3 integrin functions through interactions with inactive conformations of the integrin and dramatically enhance endothelial cell permeability in response to VEGF (9,33,39).…”