Daan Pieren

134 Chapter 5 0 20 40 60 80 100 0 20 40 60 80 100 Age (years) % TIGIT + cells inCD8 + T cells 0 20 40 60 80 100 0 10 20 30 40 % TIGIT + cells in CD8 + T cells % KIR + RA + T cells in CD8 + T cells TIGIT (PE-eFluor610) CD8 (BUV395) 31 years 45 years 71 years 16.2% 52.9% 77.6% A G B C D r = 0.51 p <0.001 r = 0.729 p <0.001 E F -20 0 20 40 60 T N T CM T EM T EMRA KIR + RA + NKG2A + RA + Ratio TIGIT/CD226 (MFI) CD226 TIGIT *** T NAIVE T CM T EM KIR + RA + NKG2A + RA + T EMRA NKG2A + RA + KIR + RA + T NAIVE T EM T CM T EMRA TIGIT (PE-eFluor610) CD226 (BV786) 5.1 3.1 45.9 46.0 17.6 33.3 40.6 8.6 3.2 23.7 62.7 10.4 29.5 17.4 39.9 13.2 73.4 19.5 5.7 1.4 1.0 13.6 83.5 1.9 T NAIVE T CM T EM T EMRA KIR + RA + NKG2A + RA + 0 20 40 60 80 100 % TIGIT + cells of subset *** * *** ****** 0 20 40 60 80 100 0 20 40 60 80 100 %CD226 + cells of subset % TIGIT + cells of subset Figure 3. TIGIT Hi CD226 Low KIR + RA + T cells contribute to age-related TIGIT expression in CD8 + T cells. ( A ) Flow cytometry plots show TIGIT expression by total CD8 + T cells in selected individuals of different ages. ( B ) Relationship between the frequency of TIGIT + cells within the total CD8 + T-cell population and age in healthy individuals (n=50). ( C ) Relationship between the frequency of KIR + RA + cells and the frequency of TIGIT + cells within the CD8 + T-cell population. ( D ) The frequency TIGIT + cells within the indicated CD8 + T-cell subsets. ( E ) Representative flow cytometry plots of TIGIT and CD226 expression within each of the six CD8 + T-cell subsets. ( F ) Relationship between TIGIT + and CD226 + cell frequencies for each cell subset, as well as ( G ) the ratio between TIGIT and CD226 per cell subset based on the median expression per cell (MFI) of these markers. Correlations ( r values) were assessed by Spearman test. Statistical significance of data presented in the bar graph (means ± s.d.) was determined using Friedman test (with Dunn’s post-test). (* p <0.05, *** p <0.001).