Daan Pieren

130 Chapter 5 KIR + RA + T cells NKG2A + RA + T cells C 0 20 40 60 80 100 0 10 20 30 40 Age (years) % CD45RA + KIR + and/or NKG2A + within CD8 + T cells r = 0.32 p = 0.02 CD45RA + KIR + and/or NKG2A + in CD8 + T cells A 0 20 40 60 80 100 0 10 20 30 40 Age (years) % KIR + RA + T cells within CD8 + T cells r = 0.362 p = 0.01 0 20 40 60 80 100 0 1 2 3 4 Age (years) % NKG2A + RA + T cells within CD8 + T cells r = -0.403 p = 0.004 D B 64.2% 35.6% Total CD8 + T cells CD45RA (BV605) CD27 (BV510) KIR (PE) NKG2A (APC) 30 years 82 years NKG2A + RA + 0.45% KIR + RA + 13.6% NKG2A + RA + 1.69% KIR + RA + 2.03% E KIR + RA + NKG2A + RA + KIR + RA + NKG2A + RA + 0 20 40 60 80 100 % KIR + RA + or NKG2A + RA + within classical T NAIVE and T EMRA subsets NAIVE EMRA CD8 + T-cell subsets F T NAIVE T CM T EM T EMRA KIR + RA + NKG2A + RA + 0 20 40 60 80 % subset within total CD8 + T cells 30 years 79 years CD8 + T-cell subsets G Classical T IVE Classical T E R T NAIVE T CM T EM T EMRA KIR + RA + NKG2A + RA + Figure 1. KIR + RA + T cells accumulate with age, whereas NKG2A + RA + T cells decline with age. KIR and NKG2A expression by CD45RA + CD8 + T cells was analyzed in a cohort of healthy individuals ranging from 20-82 years of age (n=50) using flow cytometry. ( A ) Relationship between the proportion of the virtual memory cell subset (CD45RA + cells expressing KIR + and/ or NKG2A + ) within the CD8 + T-cell population and age. ( B ) Gating strategy to separate the virtual memory cell subset into KIR + NKG2A - CD45RA + CD8 + T cells (KIR + RA + T cells, blue gate, % in total CD8 + T cells) and KIR - NKG2A + CD45RA + CD8 + T cells (NKG2A + RA + T cells, orange gate). Relationship between ( C ) KIR + RA + and ( D ) NKG2A + RA + cell proportions within the total CD8 + T-cell population and age. ( E ) Proportions of KIR + RA + and NKG2A + RA + T cells within the classically defined T NAIVE (CD45RA + CD27 + CD8 + T cells) and T EMRA (CD45RA + CD27 - CD8 + T cells) subsets. ( F ) Proportions of the six CD8 + T-cell subsets among the CD8 + T-cell population. ( G ) The proportional change with age of each cell subset within the CD8 + T-cell population of representative individuals at young and older age. Correlations ( r values) were assessed by Spearman test. Bar graphs show means ± s.d.