FIG 6.

Expression of α-Gal on A549 cells renders VSV-GP serum sensitive. (A) The human cell line A549 was stably transduced with 3Galβ1-GlcNAc-α1-galactosyltransferase (α-GT), which leads to the presence of the α-Gal epitope on the cell surface. The expression of the xenoantigen α-Gal on nontransduced A549 cells and transduced α-Gal-A549 cells was determined with an anti-α-Gal antibody, followed by incubation with a labeled secondary antibody. Subsequently, the cells were analyzed by flow cytometry. As a positive control, mouse L929 cells were used; as a negative control, an appropriate isotype control was used. (B and C) VSV-GP was produced on α-GT-transduced cells [VSV-GP(α-Gal A549)]. Serum resistance assays of VSV-GP(A549) (B) and VSV-GP(α-Gal-A549) (C) were performed in the presence or absence of soluble α-Gal. Virus titers were determined by plaque titration. The data show the results of two independent experiments with two technical replicates. Mean values are shown, and error bars indicate the SD. Data were analyzed by GraphPad Prism software using ANOVA, followed by Dunnett’s multiple-comparison test (***, significant at P < 0.001).