FIG. 3.

Permeability of T cells, B cells, and gp51-positive PBMC from BLV-positive cattle. PBMC from BLV-positive cattle were incubated for 1 h with 3-kDa (A), 40-kDa (B), or 70-kDa (C) fluorescein-conjugated dextrans (green fluorescence) and analyzed by flow cytometry. Lymphocyte subpopulations were identified on the basis of staining with Tricolor-labeled monoclonal antibodies (red fluorescence) as T cells (positive for bovine CD3 and comprising 26% of the total cells), B cells (positive for CD21-like antigen and comprising 48% of the total cells), and gp51-positive cells (BLV-expressing cells positive for viral gp51 antigen and comprising 1.6% of the cells) (designations at right of each graph). Cells were assessed for dextran content by measuring green fluorescence; cells exhibiting fluorescence below 1.1 log were considered dextran negative (N) and cells exhibiting fluorescence above 1.1 log were considered dextran positive and were divided into groups of cells exhibiting low fluorescence (L; 1.1 to 2.05 log) or high fluorescence (H; 2.05 to 3.7 log). Data are histograms of dot plots (50,000 cells per sample) from a representative experiment with one BLV-positive cow. The cell numbers are relative and are not comparable between histograms, because the individual histograms were scaled independently.