Adenosine 5′-triphosphate (ATP)-mediated stimulation and suppression of DNA synthesis in lymphoid cells. II. Suppressive effect of ATP on murine T-cell functions

The suppressive effects of ATP on murine T-cell functions were studied. The suppressive effects of ATP as well as adenosine on the DNA synthesis of spleen cells are due to the presence of mature T-cells, because ATP has no suppressive effect on athymic nu/nu spleen cells. Further characterization of the cells which are responsible for ATP-mediated suppression of DNA synthesis revealed that the cells are nylon wool-adherent T-cells and PHA-reactive T-cells. In addition, the suppressive effects of ATP on both spontaneous and mitogen-induced proliferative responses are stronger than that of adenosine, and T-cells are more sensitive to ATP than B-cells. The observation that both ATP and adenosine have unique effects on T-cells compared to B-cells may contribute toward explaining why patients with severe combined immunodeficiency (SCID) associated with adenosine deaminase (ADA) deficiency have greater T-cell than B-cell abnormalities.