P55 TUMOR-NECROSIS-FACTOR RECEPTORS DISTRIBUTION IN NEUROBLASTOMA-CELLS

p55 tumour necrosis factor receptors in neuroblastoma SKNBE cells were localized by immunofluorescence microscopy. They were detected at the surface on nonpermeabilized cells and, after differential permeabiliz ation, in the Golgi area as diffuse staining and in the perinuclear re gion as clusters and punctuations. Intracytoplasmic punctuate forms we re detected after permeabilization with Triton X-100, suggesting their location within organelles. Treatment with the differentiation-induci ng agent all-trans retinoic acid (RA) greatly increased the cellular d ensity of the immunoreactive receptors and receptors were detected in the newly formed neurites, suggesting that RA promoted their transport from the cell body. The results suggest direct influences on neuronal functions of tumour necrosis factor ct released from adjacent or from target cells.