FIG 6.
oBST2B reduces the incorporation of JSRV Env into virions. (A) Representative Western blots of concentrated viral particles from supernatants (virus) and cellular extracts (lysates) of mock-CPT-Tert-transfected cells (M) or cells transfected with expression plasmids for full-length JSRV21 and 1 μg of expression plasmids for oBST2B (2B) or oBST2B-HA (2B-HA) or an empty pcDNA3.1 control (−). Blots were incubated with the appropriate antisera as indicated in each panel. (B) Viral-particle release and Env incorporation in the presence of an increasing amount of oBST2B or oBST2B-HA (0.25 μg to 2 μg) were detected with an anti-Gag (CA) and anti-Env (SU) antibodies and quantified by chemifluorescence. (C and D) Values for CA and SU expression were related to values obtained for cells cotransfected with an expression plasmid for JSRV21 and the empty pcDNA3.1 plasmid (taken as 100). Blots represent the ratios of SU/CA expression calculated from three independent experiments. (C) A two-way statistical ANOVA shows that there is no difference in the relative SU/CA ratios between cells transfected with oBST2B- and oBST2B-HA-expressing plasmids (P = 0.74). (D) These ratios are negatively correlated with the quantity of transfected plasmids (P = 0.006). Open circles are ratio values; black circles (C) or horizontal bars (D) represent the mean ratios of the data obtained.