Figure 6.

Schematic overview of how membrane-associated (a) and soluble (b) host lectins can be implicated in interactions that benefit the virus and facilitate viral infection and spread. (a.1) Binding of virion-associated glycans to membrane-associated host lectins can promote (cis-) infection of the lectin-expressing cell: host lectins may facilitate viral attachment, internalization, and fusion (depending on specific virus biology). Viral attachment to membrane-associated host lectins may trigger signaling mechanisms that facilitate viral infection, spread, and/or immune evasion. (a.2) Binding of virion-associated glycans to membrane-associated host lectins can promote presentation of the virus to susceptible target cells in trans, thereby facilitating target cell infection. Viral attachment to membrane-associated host lectins may trigger signaling mechanisms that facilitate viral infection, spread, and/or immune evasion. (b.1) Multivalent soluble host lectins may facilitate virus attachment and promote viral infection by crosslinking virus- and host cell-displayed glycans. (b.2) Virus recognition by soluble host lectins and subsequent association with target cell-expressed lectin receptors may promote cis-infection of target cells. In a similar manner, soluble host lectins may capture and concentrate virions on a cell surface for subsequent presentation to target cells in trans (not depicted). Moreover, lectin binding can trigger complement deposition on the virus (through the lectin pathway), which may potentially promote cis- or trans-infection via cell surface-expressed complement receptors (not depicted).