Figure 1.

Representative flow cytometry plots demonstrating detection of DURT cell populations in a typical infant. Plots represent live, CD3+ T cells co-stained with the indicated antibody-conjugate on the X-axis and the indicated tetramer reagent or antibody-conjugate on the Y-axis. (a) MR1-restricted MAIT cells (MR1-5-OP-RU tetramer on the left and MR1-6FP tetramer as negative control on the right). (b) CD1d-restricted NKT cells (CD1d-PBS57 tetramer on the left and unloaded [empty] CD1d tetramer as negative control on the right). (c) γδ T cells, defined as CD3 T cells that stained positive with anti-pan γδ TCR antibody. (d) Definition of CD1b-restricted glucose monomycolate (GMM)-specific T cells and germline-encoded mycolyl-reactive (GEM) cells in an infant sample (top plots) or a PBMC sample that was spiked with GEM T cell clone cells (bottom plots). GMM-specific T cells (left plots) were defined as CD1b-GMM tetramer⁺ T cells and GEM cells were defined as CD1b-GMM tetramer⁺ T cells that co-expressed CD4 and the TCR variable chain TRAV1–2 (red dots in right plots). Red numbers in all plots denote the percentages of T cells in that plot that stain positive for each population-defining marker out of CD3+ T cells. The red numbers in parentheses in the top, right plot in panel d denote the percentage of GEM cells out of all CD3+ T cells.