Figure 3

ILFs from aged mice contain a population of CD4+ CD8αα+ T-lymphocytes. ILF, PP, and splenocyte populations from young and aged mice were isolated and evaluated by multi-color flow cytometry for the presence of CD4+ and CD8α+ T-lymphocytes (panel a). ILFs from aged mice contained a significant population of CD4+ CD8α+ T-cells, which was largely absent from the spleen and PP of aged mice and from the ILFs of young mice (panel a). Further analysis of the CD4+ CD8α+ population within ILFs from aged mice revealed that this population was CD8β-, and therefore CD8αα+ (black line histogram panel b). This CD4+ CD8αα+ T-lymphocyte population was also present in PP from aged mice, but absent from the splenocyte population of aged mice (black line histogram panel b). Within the ILF and PP population from aged mice the CD4- CD8α+ T-lymphocytes were both CD8β+ and CDβ-, while in the spleen this population was only CD8β+ (gray line histograms panel b). Data shown are representative of two or more experiments.