Endothelial galectin-1 binds to specific glycans on nipah virus fusion protein and inhibits maturation, mobility, and function to block syncytia formation.

Nipah virus targets human endothelial cells via NiV-F and NiV-G envelope glycoproteins, resulting in endothelial syncytia formation and vascular compromise. Endothelial cells respond to viral infection by releasing innate immune effectors, including galectins, which are secreted proteins that bind to specific glycan ligands on cell surface glycoproteins. We demonstrate that galectin-1 reduces NiV-F mediated fusion of endothelial cells, and that endogenous galectin-1 in endothelial cells is sufficient to inhibit syncytia formation.

Galectin-1-matured human monocyte-derived dendritic cells have enhanced migration through extracellular matrix.

Dendritic cells (DCs) are potent mediators of the immune response, and can be activated by exogenous pathogen components. Galectin-1 is a member of the conserved beta-galactoside-binding lectin family that binds galactoside residues on cell surface glycoconjugates. Galectin-1 is known to play a role in immune regulation via action on multiple immune cells.

N-glycans on Nipah virus fusion protein protect against neutralization but reduce membrane fusion and viral entry.

Nipah virus (NiV) is a deadly emerging paramyxovirus. The NiV attachment (NiV-G) and fusion (NiV-F) envelope glycoproteins mediate both syncytium formation and viral entry. Specific N-glycans on paramyxovirus fusion proteins are generally required for proper conformational integrity and biological function.

EphrinB2 is the entry receptor for Nipah virus, an emergent deadly paramyxovirus.

Nipah virus (NiV) is an emergent paramyxovirus that causes fatal encephalitis in up to 70 percent of infected patients, and there is evidence of human-to-human transmission. Endothelial syncytia, comprised of multinucleated giant-endothelial cells, are frequently found in NiV infections, and are mediated by the fusion (F) and attachment (G) envelope glycoproteins. Identification of the receptor for this virus will shed light on the pathobiology of NiV infection, and spur the rational development of effective therapeutics.

Novel innate immune functions for galectin-1: galectin-1 inhibits cell fusion by Nipah virus envelope glycoproteins and augments dendritic cell secretion of proinflammatory cytokines.

Galectin-1 (gal-1), an endogenous lectin secreted by a variety of cell types, has pleiotropic immunomodulatory functions, including regulation of lymphocyte survival and cytokine secretion in autoimmune, transplant disease, and parasitic infection models. However, the role of gal-1 in viral infections is unknown. Nipah virus (NiV) is an emerging pathogen that causes severe, often fatal, febrile encephalitis.

Constitutive and induced expression of DC-SIGN on dendritic cell and macrophage subpopulations in situ and in vitro.

DC-SIGN is a C-type lectin, highly expressed on the surface of immature dendritic cells (DCs), that mediates efficient infection of T cells in trans by its ability to bind HIV-1, HIV-2, and SIV. In addition, the ability of DC-SIGN to bind adhesion molecules on surfaces of naïve T cells and endothelium also suggests its involvement in T-cell activation and DC trafficking. To gain further insights into the range of expression and potential functions of DC-SIGN, we performed a detailed analysis of DC-SIGN expression in adult and fetal tissues and also analyzed its regulated expression on cultured DCs and macrophages.