title: Bacteria-immune system interactions. VIII. Modulation of human cytotoxic reactions by crude lipoteichoic acid extracts of Bacillus globigii.
abstract: Crude lipoteichoic acid (LTA)1 extracts were prepared from Bacillus globigii (Bg-LTA). The addition of Bg-LTA to mixed lymphocyte reactions (MLR) produced a dose dependent inhibition of specific cytotoxic reactions and of tritiated thymidine (3H-TdR) incorporation. Much less Bg-LTA was needed to inhibit the initiation (addition at day 0) than the effector phase (addition at day 6) of the cytotoxic reactions. None of the LTA quantities used had a toxic effect on the lymphocytes. LTA pretreated stimulator cells also had a modulatory effect on the cytotoxic reactions. Stimulators pretreated with very low or very high LTA concentrations had no effect; however, pretreatment with intermediate concentrations induced a drastic inhibition of cytotoxicity. LTA pretreated stimulator cells did not significantly affect 3H-TdR incorporation. Suppression of the cytotoxic reaction could also be obtained by LTA-pretreatment of the effector cells.
mesh_terms: D001407:Bacillus / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects; D007111:Immunity, Cellular / Q000187:drug effects; D008070:Lipopolysaccharides; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D010712:Phosphatidic Acids / Q000276:immunology* / Q000494:pharmacology; D013682:Teichoic Acids / Q000276:immunology* / Q000494:pharmacology; D013997:Time Factors
chemical_list: D008070:Lipopolysaccharides; D010712:Phosphatidic Acids; D013682:Teichoic Acids; C009900:lipoteichoic acid