γδ T cells and αβ T cells in peripheral blood differ fundamentally in their respective chemokine receptor expression profiles. (A) Dot plot diagrams show double staining data for CD45RO and chemokine receptors in freshly isolated peripheral blood γδ T cells (upper row) and αβ T cells (lower row). The data are representative of a study that included peripheral blood from a total of 19 donors. (B) γδ T cells and αβ T cells from the same donor blood differ substantially in their levels of cell surface CCR7 and CXCR5. Chemokine receptor staining data (open histograms) are plotted over control stainings with isotype-matched Abs (filled histograms). Bars define gates for receptor-positive cells, and numbers refer to the percent of receptor-positive cells. The Abs used in flow cytometric analysis are listed in parentheses and include 1 rat mAb (3D12) and 2 mouse mAbs (2H12, 150503) against CCR7 and 1 mouse mAb (51505.111) against CXCR5. The data are representative of a comparative analysis with peripheral blood T cells from 3 healthy individuals.