title: Hyperthermic enhancement of antibody-complement cytotoxicity against normal mouse B lymphocytes and its relation to capping.
abstract: Normal mouse B lymphocytes were exposed to water-bath hyperthermia in vitro and examined for susceptibility to antibody-complement (Ab-C) cytotoxicity. Enhancement of Ab-C cytotoxicity was observed during heat treatment at 42 or 43 degrees C. Sensitivity to Ab-C cytotoxicity returned to normal levels by 2-3 hr post exposure to 42 degrees C. No such recovery was observed when cells were preheated at 43 degrees C for 40 min. The mechanism responsible for heat-induced enhancement of Ab-C cytotoxicity may be related to the way heat affects the redistribution of membrane-bound antigen-antibody (Ag-Ab) complexes. To investigate this possibility, cells were preheated at 37, 42, or 43 degrees C. The Ab-C assay was then performed at 37 degrees C immediately or 2.5 hr after hyperthermia. The distribution of Ag-Ab complexes was evaluated by immunofluorescence. A direct correlation was found between the hyperthermic enhancement of Ab-C cytotoxicity and the hyperthermic inhibition of capping, a process where membrane-bound Ag-Ab complexes coalesce into a polar cap on the cell surface. Sensitivity to Ab-C cytotoxicity returned to normal levels when cells restored the ability to cap Ag-Ab complexes following 42 degrees C hyperthermia. Cells heated at 43 degrees C were still sensitive to Ab-C cytotoxicity and did not recover the capping ability even 2.5 hr after heat treatment.
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity / Q000528:radiation effects*; D000936:Antigen-Antibody Complex / Q000276:immunology / Q000528:radiation effects; D001402:B-Lymphocytes / Q000276:immunology / Q000528:radiation effects*; D003165:Complement System Proteins / Q000276:immunology / Q000528:radiation effects*; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D006979:Hyperthermia, Induced; D007152:Immunologic Capping / Q000528:radiation effects*; D066298:In Vitro Techniques; D051379:Mice; D013696:Temperature; D013997:Time Factors
chemical_list: D000936:Antigen-Antibody Complex; D003165:Complement System Proteins