IL-7–induced α4β7 expression is dose and time dependent. (A) Dose-response effects of IL-7 on α4β7 expression in purified naive CD4⁺ T lymphocytes after 72 hours of culture. The shaded histograms denote the staining of IL-7–treated cells; the empty profiles denote the staining of control, untreated cells. Data are representative of 3 independent experiments performed with similar results. (B) Expression of α4β7 as evaluated by flow cytometry over a period of 7 days in purified naive CD4⁺ T cells that were either untreated or treated with IL-7 at 5 ng/mL. The values of MFI are shown. Data are representative of 3 independent experiments performed with similar results.