Immunosenescence phenotypes in Ews^−/− mice. (A) Peripheral blood leukocytes from Ews^+/+ and Ews^−/− recipients were stained with anti-B220 and anti-CD11b antibodies at 4 weeks (top panel) and 5 months (bottom panel) after transplant. (B) One week after immunization with TNP-Ovalbumin, spleen cells were prepared from Ews^+/+ and Ews^−/− mice, and then challenged with different concentrations of ovalbumin as indicated. Concentrations of the indicated cytokines were determined by enzyme-linked immunosorbent assay. The means were derived from 3 independent experiments: 2-tailed Student t test, n = 3, ***P = .0008.