Fig. 1

Age is associated with alterations in phenotypic profiles of human LP CD4 T cells. LPMC were isolated from colonic tissue samples obtained from younger (Y; ≤45 yrs) and older (O; ≥65 yrs) persons (N = 9/age group unless otherwise stated) and multi-color flow cytometry used to evaluate a baseline frequencies and baseline expression of b Bcl-2, c CD38 and HLA-DR (Y N = 8; O N = 7), CD25, Ki67 (O N = 8), CD57 (Y N = 8; O N = 7) or d CTLA-4 (Y N = 8; O N = 8) and PD-1 (Y N = 8; O N = 7). Frequency values are shown as a percentage of LP CD4 T cells in viable, CD45⁺ LPMC or as absolute number per gram and phenotypic expression as the percentage of LP CD4 T cells expressing each marker or as total expression levels on LP CD4 T cells (Geometric Mean Fluorescence Intensity; GMFI). Isotype control (Bcl-2, CD38, Ki67, CTLA-4), Fluorescence minus one (FMO; CD25) or FM4 (HLA-DR, CD57, PD-1) values have been removed (net). Bar graphs represent mean ± SEM with individual samples shown as open squares. Statistical analysis: unpaired t-tests