The adenosine receptor mediated accumulation of cyclic AMP in Jurkat cells is enhanced by a lectin and by phorbol esters.

The accumulation of cyclic AMP in Jurkat cells was stimulated by adenosine and adenosine analogues. The accumulation of cyclic AMP induced by these agents was competitively antagonized by the adenosine receptor antagonist 8-p-sulphophenyl-theophylline (KD appr 1.9 microM). The lectin PHA, the diacylglycerol OAG as well as tumor promoting phorbol esters enhanced the accumulation of cyclic AMP induced by the adenosine analogue NECA. The results suggest that activation of CD2/CD3 receptors by lectins could potentiate the endogenous cyclic AMP stimulator adenosine via activation of protein kinase C.