0000000000373157
AUTHOR
Ingo B. Autenrieth
Activation of NF-kappaB and IL-8 by yersinia enterocolitica invasin protein is conferred by engagement of rac1 and MAP kinase cascades.
International audience; Yersinia enterocolitica triggers activation of the nuclear factor (NF)-kappaB and production of the proinflammatory chemokine interleukin (IL)-8 in intestinal epithelial cells. This activation is due to adhesion of the bacteria via their outer membrane protein invasin to the host cells. Using Clostridium difficile toxins that specifically inactivate small GTPases, and transfection of inhibitory proteins of the Rho-GTPases, we demonstrate that Rac1, but not Cdc42 or Rho, is required for activation of NF-kappaB by invasin. Invasin activated the mitogen activated protein kinases (MAPK) p38 and c-Jun N-terminal protein kinase (JNK) but not extracellular signal regulated …
Ambiguous Role of Interleukin-12 in Yersinia enterocolitica Infection in Susceptible and Resistant Mouse Strains
ABSTRACT Endogenous interleukin-12 (IL-12) mediates protection against Yersinia enterocolitica in C57BL/6 mice by triggering gamma interferon (IFN-γ) production in NK and CD4 + T cells. Administration of exogenous IL-12 confers protection against yersiniae in Yersinia -susceptible BALB/c mice but exacerbates yersiniosis in resistant C57BL/6 mice. Therefore, we wanted to dissect the different mechanisms exerted by IL-12 during Yersinia infections by using different models of Yersinia -resistant and -susceptible mice, including resistant C57BL/6 mice, susceptible BALB/c mice, intermediate-susceptible wild-type 129/Sv mice, 129/Sv IFN-γ-receptor-deficient (IFN-γR −/− ) mice and C57BL/6 tumor n…
Bacteroides vulgatus protects against escherichia coli-induced colitis in gnotobiotic interleukin-2-deficient mice
Abstract Background & Aims: The microflora plays a crucial role in inflammatory bowel diseases (IBDs). Specific pathogen-free (SPF), but not germ-free, interleukin (IL)-2-deficient (IL-2−/−) mice develop colitis. The colitogenicity of commensal bacteria was determined. Methods: Gnotobiotic IL-2−/− and IL-2+/+ mice were colonized with Escherichia coli mpk, Bacteroides vulgatus mpk, or both bacterial strains, or with E. coli strain Nissle 1917. DNA arrays were used to characterize E. coli mpk. Colitis was analyzed by histology and real-time reverse-transcription polymerase chain reaction (RT-PCR) for interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-10, and CD14 messenger RNA (mRNA) expre…