Figure 2.

Gating strategy Flow cytometric analysis of bacillus Calmette-Guérin (BCG)–induced T cell cytokine production. Whole blood was incubated with BCG for 12 hours. Representative dot plots from a single participant are shown. (A) Gating strategy used to identify CD4, CD8, and γδ T cells. From left to right, leukocytes from whole blood were acquired and cell doublets excluded with forward scatter area versus forward scatter height parameters. T cells were identified by assessing CD3 expression against IFN-γ expression, which enables inclusion of any T cells that may have down-regulated CD3 expression upon activation. Subsequently, CD3⁺ T cells were differentiated into conventional T cells, which did not express γδ T cell receptor, and γδ T cells, by assessing γδ expression against CD8 expression. Finally, the conventional T cell population was divided into CD4⁺ and CD8⁺ T cells. (B) Representative dot plots of cytokine coexpression patterns in CD4 T cells from unstimulated, BCG, and staphylococcal enterotoxin B (SEB)–stimulated conditions. APC = allophycocyanin; Cy5.5PerCP-A = cyanine peridinin chlorophyll protein; FSC = forward scatter.