FIG. 1.

Flow cytometry gating scheme. This figure illustrates the gating strategy used in analysis of five-color, three-function flow cytometry data. Data are shown for rectal mononuclear cells from patient 37 stimulated with HIV Gag peptides. After initial gating on lymphocytes, cells were first selected based on CD3⁺ CD8⁺ staining and then divided into three individual response gates consisting of cells positive for CD107, IFN-γ, or TNF-α. Cells within these individual response gates were then entered into Boolean gating analysis to generate frequencies for the eight possible combinations (i.e., positive or negative) of the three functions (FlowJo software; TreeStar).