Endothelial Galectin-1 Binds to Specific Glycans on Nipah Virus Fusion Protein and Inhibits Maturation, Mobility, and Function to Block Syncytia Formation
Figure 4
Galectin-1 inhibits NiV-F0 endocytosis and maturation.
A, Galectin-1 decreases internalization of NiV-F0 from the plasma membrane. Cells transfected with NiV-F were cell surface biotinylated, then incubated in the presence of 20µM galectin-1 (bold line), or buffer control (dashed line), for the indicated times to allow internalization. Internalized biotinylated NiV-F was quantified by ELISA. Percent internalization was determined as the amount of internalized biotinylated NiV-F compared to total biotinylated NiV-F at the initial timepoint. Data are mean ± SEM for seven replicate experiments. B, Galectin-1 inhibits NiV-F0 proteolytic processing. 293T cells expressing NiV-F were pulse-labeled with 35S-methionine, then chased for 4 or 6 hrs in the presence or absence of galectin-1. NiV-F was immunoprecipitated with anti-NiV-F polyclonal sera and proteolytic processing analyzed by immunoblotting. C, Graphic representation of data in B. Cleavage ratio was determined as the amount of processed NiV-F (F1+F2) compared to total NiV-F protein. Data are mean ± SEM of three replicate experiments.