title: T-cell-independent macrophage activation in mice induced with rRNA from Listeria monocytogenes and dimethyldioctadecylammonium bromide.
abstract: Purified rRNA from Listeria monocytogenes or Pseudomonas aeruginosa injected in combination with dimethyldioctadecylammonium bromide (DDA), protects mice nonspecifically against a lethal challenge of various extra- and intracellular bacteria. In the present study vaccination of BALB/c as well as C57BL/Ka mice with listerial RNA-DDA resulted in activation of fixed-tissue macrophages, as measured by an enhanced in vivo L. monocytogenes killing in spleen and liver. Evidence was found that macrophage activation by vaccination with rRNA-DDA occurred by a T-cell-independent mechanism. Treatment of mice with cyclosporin A had no effect on the enhanced L. monocytogenes killing induced with RNA-DDA; in vitro exposure of RNA-DDA to spleen cell cultures did not give rise to any lymphocyte proliferation. No evidence could be found for a possible adjuvant activity for RNA-DDA in cellular responses; in fact, RNA-DDA had an inhibitory effect on lymphocyte proliferative responses to Listeria antigen and to concanavalin A.
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D003524:Cyclosporins / Q000494:pharmacology; D005260:Female; D008089:Listeria monocytogenes / Q000276:immunology*; D008099:Liver / Q000382:microbiology; D008213:Lymphocyte Activation; D008262:Macrophage Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D012335:RNA, Ribosomal / Q000494:pharmacology*; D013154:Spleen / Q000382:microbiology; D013601:T-Lymphocytes / Q000502:physiology*; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D003524:Cyclosporins; D000644:Quaternary Ammonium Compounds; D012335:RNA, Ribosomal; C015831:dimethyldioctadecylammonium