FIG. 2.

Effect of CAML overexpression on Tetherin expression at the surfaces of permissive Cos-7 cells. (A to C) Cos-7 cells were mock transfected or transfected with the HxBH10vpu_wt or HxBH10vpu− proviral construct. Forty-eight hours posttransfection, cell surface expression of Tetherin was evaluated after surface staining using anti-Tetherin antibodies, followed by flow cytometry. Tetherin antiserum was produced in rabbits by using a glutathione S-transferase-Tetherin fusion protein composed of Tetherin amino acids 40 to 181, produced in bacteria, thus generating a polyclonal antibody against the extracellular portion of Tetherin. In each panel, the gray-filled histogram represents results for mock-transfected cells stained with the preimmune rabbit serum (unstained control) while the other histograms represent results for cells stained with anti-Tetherin polyclonal rabbit serum. The histogram with a solid line represents data for mock-transfected cells, the histogram with a dotted line corresponds to mock-transfected cells treated with 10,000 U/ml of IFN-α, and the dashed-line histogram represents data for cells expressing hCAML. Mean fluorescence intensity (MFI) values after subtraction of the value for the unstained control are indicated for each sample. Stained cells were analyzed on a FACSCalibur instrument (BD Biosciences Immunocytometry Systems), and data analysis was performed by using CellQuest Pro (BD Biosciences) and FlowJo software version 7.25 (Tree Star). agm, African green monkey cells.