Objective and design: The impaired function of T cells is characteristic of HIV infection. It contributes to disease pathogenesis and is associated with disease prognosis. Our aim was to describe a biochemical basis for this impairment and a pharmacological way of restoring function.
Methods: Measurement of intracellular cAMP, protein kinase A (PKA) activity and proliferative capacity of T cells to recall antigens.
Results: HIV-seropositive individuals without AIDS showed significant increases in intracellular cAMP levels and PKA activity (inhibitors of lymphocyte function). The proliferative capacity of T cells to recall antigens correlated inversely with initial cAMP levels: poor proliferation was associated with high cAMP level in HIV infection. Moreover, drugs that reduced intracellular cAMP levels led to significant restoration of specific T-cell proliferation and cytotoxicity.
Conclusions: Our findings indicate that high intracellular cAMP concentrations contribute to pathogenesis of T-cell anergy in HIV infection and that drugs that decrease intracellular cAMP levels may be beneficial in the treatment of AIDS.