Fig 7. Increased intracellular levels of BMP promote fusion of LASV pseudoviruses.

(A) Images of CHO and CHO.NPC1mut cells permeabilized and stained for cholesterol with filipin and for BMP with anti-BMP antibody. Cell nuclei were stained with far-red dye. (B) Quantification of the levels of cholesterol and BMP based on fluorescence intensity per cell after background subtraction. 6 fields of view, each containing ~30 cells were analyzed. (C) Fusion activity of LASVpp, EBOVpp, IAVpp and VSVpp in CHO and CHO.NPC1mut cells measured by a BlaM assay. As negative controls, fusion experiments were carried out in the presence of 40 mM NH₄Cl. Data are means and SD of two independent experiments performed in triplicate. NS, not significant. (# denotes that, although promotion of IAVpp fusion did not reach significance due to variation between independent experiments, enhancement of IAV fusion was significant in each experiment performed in triplicate).