Figure 3.

(A) Differentiation of T_CM cell subsets in response to TCR or cytokine stimulation. Purified CD4⁺ T cell subsets were CFSE labeled and stimulated with TSST-loaded DCs or with IL-7 and IL-15 in the presence of neutralizing anti–IL-4 and anti–IL-12 antibodies. After 7 d, cells were stimulated with PdBu and ionomycin, stained with APC-labeled anti–IFN-γ and PE-labeled anti–IL-4 antibodies, and cells of the same division number were analyzed by flow cytometry. Unstimulated T cell subsets were also analyzed ex vivo as control. Numbers indicate the percentage of cells producing IFN-γ or IL-4. One respresentative experiment out of five is shown. (B and C) Modulation of homing receptor expression by cytokine-stimulated CD4⁺ memory T cell subsets. Purified CFSE-labeled CD4⁺ T cell subsets were stimulated with IL-7 and IL-15. T_CM and T_EM cells in B were sorted for CXCR5, CCR7, and CD62L expression, whereas in C they were sorted for CXCR5, CCR7, CXCR3, and CCR4 expression as indicated. After 7 d, cells in division four were analyzed for the expression of CXCR5, CCR7, and CD62L (B), or CXCR3, CCR4, and CCR5 (C). One representative donor out of four is shown.