Fig. 1.
Exhausted CD8 T cells expressed elevated levels of Dopamine Receptor D1 (DRD1). (A) Dopamine levels were assessed by enzyme-linked immuno sorbent assay in plasma collected from C57BL/6 mice infected orally with 10 cysts of Toxoplasma gondii (ME49 strain). (B) PD-1 and DRD1 expressions were evaluated by polychromatic flow cytometry on brain CD8 T cells from chronically infected mice (week 6). The top panel depicts the percentage of CD8 T cells that stain for PD-1 and DRD1 (or control antibody) as contour plots. The bottom panel represents as bar graphs the percentage of DRD1 expressing CD8 T cells in healthy (PD-1intermediate/low) and exhausted (PD-1high) CD8 subsets. The data is representative of 2 experiments with at least 4 mice per condition. Error bars represent SE throughout.