title: Selective inhibition by monosaccharides of tumor cell cytotoxicity mediated by mouse macrophages, macrophage-like cell lines, and natural killer cells.
abstract: A series of monosaccharides were tested for their ability to inhibit the effector phase of macrophage-mediated cytolysis against two susceptible murine tumor target cells, L5178Y and RL male I. Two monosaccharides, D-mannose and N-acetyl-D-galactosamine, were found to decrease cytotoxicity consistently in a dose-dependent manner. However, D-mannose preferentially inhibited lysis of RL male I target cells with little effect on lysis of L5178Y target cells, while the reverse was found with N-acetyl-D-galactosamine. Neither monosaccharide interfered with the activation of macrophages by polyinosinic:polycytidylic acid. Natural killer cell activity was decreased by a 25 mM concentration of D-mannose but not by N-acetyl-D-galactosamine, although increasing concentrations of N-acetyl-D-galactosamine were inhibitory. Neither monosaccharide affected cytotoxicity by alloimmune T cells. Cytotoxicity of macrophage-like cell lines against tumor target cells was also decreased by monosaccharides but the pattern of inhibition was different from that seen with activated macrophage effector cells. Both D-mannose and N-acetyl-D-galactosamine inhibited glucose oxidation by activated macrophages but only D-mannose significantly decreased protein synthesis of activated macrophages. These results indicate that monosaccharides can inhibit macrophage-mediated cytotoxicity in a selective manner with the pattern dependent on the tumor target cell used in the assay.
mesh_terms: D000818:Animals; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007940:Leukemia L5178 / Q000276:immunology*; D007942:Leukemia, Experimental / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D009005:Monosaccharides / Q000494:pharmacology*
chemical_list: D009005:Monosaccharides