Impact of IL-7 on CD45RO and Ki67 expression.

(A) CD45RA⁺CD45RO⁻ T cells were isolated and left untreated or treated with IL-7 (1000 U/mL), IL-2 (100 U/mL), or PHA (4 μg/mL). The cells were stained for CD45RO, CD4, CD8, and intracellular Ki67 and analyzed by flow cytometry by gating on total lymphocytes (panels Ai, Aiv, Avii), on CD4⁺ T cells (panels Aii, Av, Aviii), or on CD8⁺ T cells (panels Aiii, Avi, Aix). The top panel represents CD45RO⁻Ki67⁺cells; the middle panel represents CD45RO⁺Ki67⁺cells; and the bottom panel represents CD45RO⁺Ki67⁻ cells. Cell surface and intracellular staining was performed on day 0 and day 6 after treatment. All values represent the median of 5 different donors treated in triplicates. *P < .05 (significant) of IL-7 (panels Ai-Aiii) or PHA (panels Aiv-Aix) treatments over the other culture conditions, which were based on the Kruskal Wallis test. **P < .05 (significant) PHA induction of percentage of expression of CD8⁺CD45RO⁺Ki67⁺cells over untreated and IL-7–treated cultures but not IL-2–treated naive T cells. (B) A representative Ki67 staining of naive T cells untreated (panel Bi), treated with IL-7 (panel Bii), treated with IL-2 (panel Biii), or treated with PHA (panel Biv).