FIG 4.

Detection of cell associated and soluble truncated and full-length IFN-αβ decoy receptors. (A) Uninfected HeLa cells and HeLa cells infected for 16 to 18 h with ACAM or CL3 were incubated without (-) or with (+) IFN-α-2Fc followed by anti-Fc-APC, and fluorescence was detected in a flow cytometer. A total of 10,000 to 70,000 events were collected for each sample. The percentages of cells above the gate are indicated. (B) The medium from HeLa cells that were uninfected or infected with ACAM or CL3 for 16 to 18 h was collected and clarified by centrifugation. Uninfected HeLa cells were incubated with the medium followed by IFN-α-2Fc and anti-Fc-APC. The percentages of cells above the gate are indicated. (C) HeLa cells were infected with ectromelia (ECTV), ACAM, or CL3 for 24 h. The lower panels show staining with MAb 10G7 (+) followed by APC-conjugated anti-mouse secondary antibody. The upper panels are controls in which the 10G7 MAb was omitted (-) and staining was just with the secondary antibody. The percentages of cells above the gate are indicated.