NGF retards apoptosis in chick embryo bursal cell in vitro.

Recent studies have demonstrated that the action of nerve growth factor (NGF) is not restricted to neuronal cells but also affects cells of the immune system. In a previous work on the effect of NGF on the chick embryo bursa of Fabricius both in vivo and in vitro, we observed that NGF prolongs bursal cell survival in vitro. In the present study we report that the increase of viable cells in NGF-treated cultures is not due to a proliferative effect of NGF on bursal cells but to a reduction of cell mortality. The morphological analysis revealed that bursal cells in cultures die by apoptosis, which was also shown by the typical pattern of DNA fragmentation, a hallmark of this cell death process. It is concluded that NGF, with an action similar to that described in sympathetic neurons and PC12, could retard bursal cell death by influencing apoptosis.