EXPRESSION OF THE 4C5 ANTIGEN DURING DEVELOPMENT AND AFTER INJURY OF THE RAT SCIATIC-NERVE

We have previously reported the production of monoclonal antibody 4C5 that recognizes a cell surface neuron specific antigen, the 4C5 antige n (Thomaidou and Patsavoudi: Neuroscience 53:813-827, 1993), Antibody perturbation experiments have suggested that the 4C5 antigen is involv ed in granule cell migration processes in vitro (Thomaidou et al: J Ne urochem 64:1937-1944, 1995), In the present study, we have used monocl onal antibody 4C5 to investigate the cellular distribution and the exp ression of the corresponding antigen during development, and after inj ury of the rat sciatic nerve, Immunocytochemistry revealed presence of the protein both in myelin and non-myelin forming Schwann cells, West ern blot analysis showed that monoclonal antibody 4C5 recognizes the s ame 94 kdalton polypeptide in the sciatic nerve as in the brain, Immun ocytochemical analysis revealed an age-dependent decline of the 4C5 an tigen expression, Moreover, following adult sciatic nerve crush, 4C5 i mmunoreactivity becomes intense in Schwann cells of the distal segment , as early as 4 days after injury and remains at relatively high level s up to 2 weeks after the crush, By the 3rd week, 4C5 immunoreactivity is greatly reduced, and by the 4th week it is hardly detectable, Our results concerning the cellular localization and temporal expression o f the 4C5 antigen during development and after injury of the rat sciat ic nerve, suggest that it may participate in Schwann cell migrations t hat occur during such processes. (C) 1996 Wiley-Liss, Inc.