The number of glycosylation sites present on HA determines the virus infection rates in DC-SIGN expressing cells.

<p>MDCK (A) and Vero (B) cells, transfected with the DC-SIGN gene (black bars) or not (white bars) were treated with neuraminidase from vibrio cholerae and GolgiStop for 30 minutes to remove sialic acids from the cell surface. These cells were subsequently inoculated with A/Netherlands/26/07, A/Netherlands/26/07-Δ125, A/Netherlands/602/09, A/Netherlands/602/09-Δ276 or A/Netherlands/602/09-VN54 N125 N160. The percentage of infected cells relative to the positive control (untreated cells still possessing sialic acid) was assessed after detecting infected cells using a FITC-labeled antibody to the viral nucleoprotein and flow-cytometry.