(A) One cytometry data set is plotted on the first three principal component axes (a representative PMA+ ionomycin-stimulated CD8+ T cell sample) and shown from three different perspectives (rotated around the PC2-axis). After gating by surface marker phenotype, naive (green), central memory (Tcm, yellow), effector memory (Tem, blue), and short lived effector (Tslec, red) cell populations are overlaid to identify the main phenotypic clusters. (B and C) To analyze only memory cells, cells in the principal components PC1 versus PC2 plot in(A) were gated to exclude the naive compartment (cells with low value for PC1) and subjected to further analysis. To determine the average expression for a number of different phenotypic markers and functional capacities across the entire range of PC2 values, small bins of cells with similar PC2 values were pooled and the average intensity of each marker was determined. These average expression for each phenotypic (B) and functional (C) parameters were normalized and plotted as a function of normalized PC2 values. In this way, the phenotypic progression of CD8+ memory T cells are represented by the x axis and the y axis represents the average expression of each marker. See also