title: Effects of chloroquine, mefloquine and quinine on natural killer cell activity in vitro. An analysis of the inhibitory mechanism.
abstract: Natural killer (NK) cell activity against K 562 target cells was inhibited by pharmacological concentrations of chloroquine, mefloquine and quinine. The most potent were mefloquine and quinine. The drug-induced inhibition of the NK cell activity was abolished by addition of alpha-interferon (IF) or interleukin 2 (Il-2); preincubation of mononuclear cells with IF or Il-2 followed by addition of anti-malarial drugs decreased the inhibitory effects of the drugs. The drug-induced inhibition of the NK cell activity was not dependent on the presence of monocytes. Using monocyte depleted Percoll fractionated NK cell enriched populations in a single cell agarose assay, it was shown that the inhibitory effects of mefloquine, but not of chloroquine and quinine were due to an inhibition of the formation of effector/target cell conjugates.
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D002738:Chloroquine / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007113:Immunity, Innate / Q000187:drug effects*; D066298:In Vitro Techniques; D007372:Interferons / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology*; D015767:Mefloquine; D011803:Quinine / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*
chemical_list: D007376:Interleukin-2; D011804:Quinolines; D002738:Chloroquine; D007372:Interferons; D011803:Quinine; D015767:Mefloquine