0000000000349171
AUTHOR
Jacek Szeliga
The Host Response toListeria monocytogenesMutants 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 activi…
Characterization of the Adjuvant Effect of IL-12 and Efficacy of IL-12 Inhibitors in Type II Collagen-Induced Arthritis
A destructive joint disease can be induced in susceptible DBA/1 mice by immunization with type II collagen emulsified with oil and either killed Mycobacterium tuberculosis or IL-12 as adjuvant. Cellular and humoral anti-collagen immune mechanisms appear to be involved in the pathogenesis of arthritis. We have characterized the adjuvant effect or IL-12 in more detail and addressed the question whether mycobacteria might act via the induction of endogenous IL-12. Injections of IL-12 into collagen-immunized DBA/1 mice promoted the development of IFN-gamma-producing CD4+ T cells and strongly upregulated the production of complement-fixing IgG2a and IgG2b antibodies resulting in severe arthritis…