Figure 3.
Phenotypic characterization of MAIT cells in blood and oesophageal tissues. MAIT cell (CD3+/Vα7.2+/CD161high) and T cell (CD3+) populations were gated and percentage positive expression for PD-1, NKG2A, NKG2D, and CD8 was analyzed in blood (open circles) and oesophageal tissue specimens (filled circles). BO-adjacent oesophageal tissue from n = 22 donors was used as a tissue control, and n = 11 healthy age-matched donors were used for blood controls. PD-1 expression was higher in all tissue compartments compared to blood, for both MAIT cells (A) and T cells (B). Expression of inhibitory marker NKG2A by MAIT cells (C) and T cells (D), and costimulatory marker NKG2D (E,F), respectively, for n = 23 BO and n = 51 OAC blood samples, and n = 22 BO and n = 32 OAC oesophageal tissue biopsies. (G) Representative flow cytometry plots depicting PD-1 and NKG2A co-expression gating for a single representative OAC biopsy donor. (H) Co-expression of NKG2A and PD-1 by different OAC T cell compartments. (I) CD8 expression by MAIT cells was similarly high in blood and OAC tumor tissue, for n = 13 matched OAC donors, and MAIT cells account for a substantial proportion of CD8+ T cells in blood and OAC tumors (J). Datasets were analyzed by ANOVA (Kruskal-Wallis test followed by Dunn's Multiple Comparison Test). Horizontal bars indicate median values. *p < 0.05, ***p < 0.001.