P2RX7 and infection: To investigate the “cross-talk” between P2X7 and P2Y receptors in the course of L. amazonensis infection in vivo, P2X7−/− and WT mice were infected subcutaneously (in the footpad) with 106 promastigotes of L. amazonensis, and then treated with six shots of UTP at the infected footpad, at intervals of 3 at 4 days, from 7 days post-infection.