Figure 6. Jurkat T cells generates adenosine from NAD⁺. (A) The enzymatic conversion of NAD⁺ to AMP (a CD38/CD203a-dependent reaction) and to adenosine (ADO) (a CD73-dependent reaction) was evaluated. Activated Jurkat/CD73⁻ cells were incubated for 60 min in buffer supplemented with 100 µM NAD⁺ and the resulting supernatant transferred to Jurkat/CD73⁺ cells, followed by further incubation for 30 min. (B) Supernatants from each step depicted in (A) were analyzed by HPLC for the presence of NAD⁺ catabolites. The identity of peaks was confirmed by the co-migration and absorbance spectra of reference standards using a retention time (R_t) window of ± 5%. Representative R_t plots of metabolites in a single HPLC run are shown.