Fig 4.
The inhibitory effect of anti-FN antibodies is determined by the receptor binding specificity of HA. Point mutants of WSN (HAD225G) and Indo5 (HAN182K) and their corresponding wild-type (WT) viruses were used to infect MDCK cells at an MOI of 1. Infected cells were treated with 2 μg of anti-FN/ml immediate after virus incubation. Cells treated with plain virus culture medium (No Ab) or medium containing anti-GFP antibodies (anti-GFP) were used as controls. Cells were harvested at 24 h postincubation and fixed in 4% PFA in PBS. Fixed cells were stained for M2 (green) and nuclei (blue). The samples were examined on a fluorescence microscope and photographed at a ×400 magnification.