TARGET-CELL MEMBRANE ALTERATIONS INDUCED BY LYMPHOTOXIN - ULTRASTRUCTURAL OBSERVATIONS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 86  (1) , 149-162
Abstract
Upon in vitro stimulation by antigens or mitogens, lymphocytes release a series of lymphokines. One such lymphocyte mediator is lymphotoxin, which appears to be responsible for in vitro lymphocyte-mediated cytolysis. Employing immunological EM with ferritin- or peroxidase-labeled antibody, patchy localization of the mediator was observed on the plasma membranes of target L cells exposed to [human] lymphotoxin, often in areas overlying a microfilament web. When studying lymphotoxin-affected cells by EM of freeze-fracture replicas, aggregation of particles was observed in both the cytoplasmic and extracellular leaflets of the plasma membrane, with intervening areas which were frequently particle free. Sometimes the affected cells revealed plasma-membrane lesions suggesting intramembranous blisters. [Antilymphotoxin serum was made in rabbits.].