Phosphodiesterase 7A-deficient mice have functional T cells.

Phosphodiesterases (PDEs) are enzymes which hydrolyze the cyclic nucleotide second messengers, cAMP and cGMP. In leukocytes, PDEs are responsible for depletion of cAMP which broadly suppresses cell functions and cellular responses to many activation stimuli. PDE7A has been proposed to be essential for T lymphocyte activation based on its induction during cell activation and the suppression of proliferation and IL-2 production observed following inhibition of PDE7A expression using a PDE7A antisense oligonucleotide.