FIG. 2.

Characterization of an IMV with retained EEV membrane proteins. rVV-B5R-EGFP and a nonfluorescently tagged rVV (strain IHD-J, producing predominately EEV) (42) were prepared as described in Materials and Methods and incubated with BSC40 cells at an MOI of 50 for 1 h on ice. After washing, cells were stained with an isotype control (A) or with anti-VV MAbs recognizing L1R (B) or D8L (C), specific for the IMV surface, or A56R (D), specific for the EEV surface; the cells were then analyzed by flow cytometry. BSC40 cells alone did not exhibit above-background fluorescence when stained with anti-VV MAbs (data not shown).