title: Low temperature-induced cell surface membrane vesicle shedding is associated with DNA fragmentation.
abstract: Temperature shift conditions of 0 degree to 22 degrees C or 0 degree to 37 degrees C induce the formation and shedding of membrane vesicles (MV) from P815 tumor cell surfaces. When the MV shedding process takes place at 22 degrees C it occurs without changes in cell surface membrane permeability, whereas at 37 degrees C, changes in permeability to 51Cr and trypan blue do occur, thus mimicking the lymphocyte-mediated lytic process of tumor cells [1]. The present studies demonstrate that nuclear DNA fragmentation also occurs in both 0 degree to 22 degrees C and 0 degree to 37 degrees C temperature shifts but cell surface membrane permeability to DNA fragments occurs only in the latter condition, i.e., 0 degree to 37 degrees C. The microtubule-stabilizing agent deuterium oxide (D2O) inhibited the MV shedding process, the changes in membrane permeability, and DNA fragmentation. When P815 cells which had been induced to shed MV by the 0 degree to 22 degrees C temperature shift were labeled with 51Cr and used as targets for alloimmune lymphocytes, they were found to be as susceptible to T-cell lysis as control P815 cells. This result indicates that the lytic effect of alloimmune T lymphocytes can be exerted at the target cell surface membrane level independently of nuclear DNA fragmentation.
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000648:ultrastructure*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002467:Cell Nucleus / Q000032:analysis; D003602:Cytotoxicity, Immunologic; D004273:DNA, Neoplasm / Q000378:metabolism*; D003903:Deuterium / Q000494:pharmacology; D017666:Deuterium Oxide; D012515:Mast-Cell Sarcoma / Q000648:ultrastructure*; D051379:Mice; D008870:Microtubules / Q000187:drug effects; D013601:T-Lymphocytes / Q000276:immunology; D013696:Temperature; D014867:Water / Q000494:pharmacology
chemical_list: D004273:DNA, Neoplasm; D014867:Water; D003903:Deuterium; D017666:Deuterium Oxide