Fig 2.

Characterization of MS^C69A expressed from VSV. (A) Western blot analysis with anti-HBsAg monoclonal antibody was used to assay for MS expression. BHK cells were infected with VSV-MS or VSV-MS^C69A, and 4 h postinfection, cells were treated with lactacystin or left untreated. Cells were harvested 8 h postinfection for analysis. Un, unglycosylated form; single, single-glycosylated form; double, double-glycosylated form. (B) Proteins in the lysate from VSV-MS^C69A-infected cells, both untreated and treated with lactacystin, were deglycosylated using an EndoH reaction. Numbers at right of panel A and left of panel B are molecular masses in kilodaltons. (C) Alternatively, infected BHK cell lysate and media as well as infected cultured bone marrow cell (BMC) media were collected 8 or 6 h postinfection, respectively. MS expression following infection was then determined by HBsAg ELISA. Background (measurements from empty VSV-infected cells) has been subtracted from all represented values. (D) At 8 (n = 5) and 24 (n = 5) hours after infection with VSV-MS or VSV-MS^C69A, BAL was performed on euthanized animals. An HBsAg ELISA was conducted to detect MS in the BAL fluid. The dashed horizontal line represents the background optical density value for the negative control in this assay (optical density at 450 nm = 0.027). All values are presented as the average of each group; error bars represent standard errors.