The effect of nerve growth factor on DNA synthesis, cyclic AMP and cyclic GMP accumulation by mouse spleen lymphocytes

Nerve growth factor (NGF), a trophic neuropeptide, is known to stimulate development, and to be important in the maintenance and survival of sympathetic and sensory neurons. Considering the presence of specific receptors on the surface of spleen cells, the effect of 2.5s nerve growth factor on 3H-thymidine uptake, cAMP and cAMP accumulation in mouse spleen lymphocytes has been studied. It was found that NGF added in vitro at the concentrations between 4 × 10 −7 and 4 × 10 −8 M significantly inhibited the incorporation of 3H-thymidine into lymphocytes DNA and increased cAMP levels in a dose-dependent manner but had no effect on cGMP levels. The maximal stimulation of cAMP synthesis occurred between 5 and 30 min after the NGF addition to the culture medium. When NGF was administered in vivo a significant dose-dependent inhibition of the lymphocytes proliferation was observed. These results indicate that an early increase of cAMP concentration is responsible for the antiproliferative action of NGF on mouse spleen lymphocytes and suggest that NGF could play an important role in the regulation of immune system function.