Production of 5′AMP, ADO, and inosine by human CD19⁺ B cells and CD4⁺CD39⁺ T cells. B cells and T cells were isolated from PBMC as described in Methods and materials and incubated in the presence of 20 µM ATP for various time periods before collecting supernatants for mass spectrometry. The data are means ± standard deviation from 3 independent experiments with cells of different donors.