par Buscema, Marco 
;Van De Vyver, Gisèle
Référence Journal of Experimental Zoology, 229, 1, page (7-17)
Publication Publié, 1984
;Van De Vyver, Gisèle Référence Journal of Experimental Zoology, 229, 1, page (7-17)
Publication Publié, 1984
Article révisé par les pairs
| Résumé : | Allograft rejection in sponges has been repeatedly reported to be associated with cytotoxicity and tissue necrosis. The present work was undertaken in order to investigate the cellular aspects of antagonistic allograft rejection in Axinella polypoides, as part of an extended analysis of sponge immune reactions. Allografts were made by parabiosis of sponge branches, and their reaction was followed using light, transmission, and scanning electron microscopy. Rejection began paradoxically with the strong adherence of the parabionts. After three days, the zone of contact was characterized by extensive archaeocyte invasion, intensive phagocytosis, and cell lysis. Phagocytosis, achieved by the accumulated archaeocytes, involved healthy spherulous cells, and a substantial accumulation of cellular debris resulting from lysis of randomly dispersed single cells, mainly archaeocytes. The reaction lasted seven to nine days, after which cleavage of the reaction zone occurred, resulting in the separation of the parabionts. The reaction appeared to be limited to the former zone of contact, leaving a scar of denuded skeleton network. Our results clearly point out the role of archaeocytes in the rejection processes of Axinella polypoides; they suggest that cell lysis in antagonistic rejection of sponges depends on cytotoxic interactions between archaeocytes, since these cells appear to achieve both cytotoxicity, or killing activity, and phagocytosis. Some aspects of histoincompatibility in sponges and their analogies with those found in vertebrates are discussed. Copyright © 1984 Wiley‐Liss, Inc., A Wiley Company |
