The host response to Listeria monocytogenes mutants defective in genes encoding phospholipases C (plcA, plcB) and actin assembly (actA).
Several genes involved in the determination of Listeria monocytogenes pathogenesis have been identified. Among them, plcA gene encodes phosphatidylinositol-specific phospholipase C (PI-PLC), plcB gene encodes a broad-range phospholipase C (PC-PLC), and actA encodes a protein contributing to actin assembly in infected cells. The interaction of L. monocytogenes wild type (LO 28) strain and two derivative mutants, plcA- (BUG 206) and actA-/plcB- (LUT 12), with macrophages and T lymphocytes was investigated in a mouse model of listeriosis. Both mutants showed evidence of attenuation. The plcA- mutant, but not the plcB- mutant, expressed an increase in susceptibility to the anti-listerial activity of macrophages. Both mutants showed a decreased ability to induce IL-12 production by bone marrow macrophages when co-stimulated with E. coli LPS or IFN-gamma. In vivo, L. monocytogenes plcA- mutant was found to be a more effective stimulator of T cells than the wild LO 28 strain.
Rudnicka
W
W
Department of Infectious Biology, University of Lódź, Poland.
Kaczmarek
M
M
Szeliga
J
J
Germann
T
T
Wieckowska
M
M
Rózalska
B
B
D000199:Actins / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D004926:Escherichia coli; D005260:Female; D005798:Genes, Bacterial; D018664:Interleukin-12 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D008088:Listeriosis / Q000276:immunology* / Q000382:microbiology; D008213:Lymphocyte Activation; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000382:microbiology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D010587:Phagocytosis; D010716:Phosphatidylinositols; D013154:Spleen / Q000382:microbiology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D010738:Type C Phospholipases / Q000096:biosynthesis / Q000235:genetics*
D000199:Actins; D008070:Lipopolysaccharides; D010716:Phosphatidylinositols; D018664:Interleukin-12; D010738:Type C Phospholipases