EFFECT OF ADENOSINE ON MITOGENESIS OF ADA-DEFICIENT LYMPHOCYTES

We have determined the effects of adenosine on intrinsically adenosine deaminase-deficient lymphocytes. These cells are circulating peripheral lymphocytes from a patient with T-cell immunodeficiency. The patient has been successfully treated with normal red cell transfusions. The lymphocytes contain about 8% of the normal adenosine deaminase level. Mitogen response is nearly normal but is inhibited by adenosine at one tenth the level required for inhibition of normal lymphocytes. Determination of the disappearance of exogenously added adenosine to lymphocytes cultured in horse serum suggest that (1) ADA-deficient cells are more sensitive to adenosine toxicity because of an impaired ability to deaminate adenosine and (2) that adenosine inhibits mitogenesis only if it is present during the first 24 hr of mitogen stimulation. © 1978.