Figure 1

Changes of CD3 and CD5 levels in old mice. A) Spleen cells from young (8-12 weeks old) and old (12-24 months old) mice were stained with anti-CD4-PE, anti-CD3-FITC and anti-CD5-APC, or anti-CD8-PE, anti-CD3-FITC and anti-CD5-APC antibodies and analyzed by flow cytometry. Shown are ratios of CD3 or CD5 mean fluorescence intensities obtained on gated CD4⁺ or CD8⁺ spleen cells from matched old and young individual mice. B) Spleen cells from the same set of mice were stained with anti-CD4-PE, anti-CD62L-FITC and anti-CD44-APC, or anti-CD8-PE, anti-CD62L-FITC and anti-CD44-APC antibodies and analyzed by flow cytometry. Shown are % of CD62L^hi or CD44^hi cells on gated CD4⁺ spleen cells. Similar results were seen in CD8⁺ T cells (data not shown). C) Dot plot showing relationship between %CD62L^hi cells found in spleens of old mice and the ratio of CD5 mean fluorescence intensities (CD4⁺ T cells in old/CD4⁺ T cells in young mice). As a reference, the value found in young mice is displayed as closed circle. Two cohorts, each consisting of 10 old mice were compared to two sets of 10 young mice and cumulative data is shown. D) Shown are representative histograms of CD3, CD5, CD44, and CD62L staining on gated CD4⁺ T cells analyzed in A-C, depicting the two patterns of CD5 expression that appear in old mice.