scholarly journals Role of Flagellin and the Two-Component CheA/CheY System of Listeria monocytogenes in Host Cell Invasion and Virulence

2004 ◽  
Vol 72 (6) ◽  
pp. 3237-3244 ◽  
Author(s):  
Lone Dons ◽  
Emma Eriksson ◽  
Yuxuan Jin ◽  
Martin E. Rottenberg ◽  
Krister Kristensson ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Wild Type Strain ◽  
Tumor Necrosis Factor Receptor ◽  
Soft Agar ◽  
Initial Contact ◽  
Wild Type ◽  
Chemotaxis Proteins ◽  
Deficient Mice ◽  
Necrosis Factor

ABSTRACT The flagellum protein flagellin of Listeria monocytogenes is encoded by the flaA gene. Immediately downstream of flaA, two genes, cheY and cheA, encoding products with homology to chemotaxis proteins of other bacteria, are located. In this study we constructed deletion mutants with mutations in flaA. cheY, and cheA to elucidate their role in the biology of infection with L. monocytogenes. The ΔcheY, ΔcheA, and double-mutant ΔcheYA mutants, but not ΔflaA mutant, were motile in liquid media. However, the ΔcheA mutant had impaired swarming and the ΔcheY and ΔcheYA mutants were unable to swarm on soft agar plates, suggesting that cheY and cheA genes encode proteins involved in chemotaxis. The ΔflaA, ΔcheY, ΔcheA, and ΔcheYA mutants (grown at 24°C) showed reduced association with and invasion of Caco-2 cells compared to the wild-type strain. However, spleens from intragastrically infected BALB/c and C57BL/6 mice showed larger and similar numbers of the ΔflaA and ΔcheYA mutants, respectively, compared to the wild-type controls. Such a discrepancy could be explained by the fact that tumor necrosis factor receptor p55 deficient mice showed dramatically exacerbated susceptibility to the wild-type but unchanged or only slightly increased levels of the ΔflaA or ΔcheYA mutant. In summary, we show that listerial flaA. cheY, and cheA gene products facilitate the initial contact with epithelial cells and contribute to effective invasion but that flaA could also be involved in the triggering of immune responses.

scholarly journals Role of TNFR1 in the innate airway hyperresponsiveness of obese mice

2012 ◽  
Vol 113 (9) ◽  
pp. 1476-1485 ◽  
Author(s):  
Ming Zhu ◽  
Alison S. Williams ◽  
Lucas Chen ◽  
Allison P. Wurmbrand ◽  
Erin S. Williams ◽  
...  
Keyword(s):  
Airway Hyperresponsiveness ◽  
Bronchoalveolar Lavage Fluid ◽  
Pulmonary Inflammation ◽  
Tumor Necrosis Factor Receptor ◽  
Lavage Fluid ◽  
Forced Oscillation Technique ◽  
Obese Mice ◽  
Wild Type ◽  
Necrosis Factor

The purpose of this study was to examine the role of tumor necrosis factor receptor 1 (TNFR1) in the airway hyperresponsiveness characteristic of obese mice. Airway responsiveness to intravenous methacholine was measured using the forced oscillation technique in obese Cpe fat mice that were either sufficient or genetically deficient in TNFR1 ( Cpe fat and Cpe fat/TNFR1−/− mice) and in lean mice that were either sufficient or genetically deficient in TNFR1 [wild-type (WT) and TNFR1−/− mice]. Compared with lean WT mice, Cpe fat mice exhibited airway hyperresponsiveness. Airway hyperresponsives was also greater in Cpe fat/TNFR1−/− than in Cpe fat mice. Compared with WT mice, Cpe fat mice had increases in bronchoalveolar lavage fluid concentrations of several inflammatory moieties including eotaxin, IL-9, IP-10, KC, MIG, and VEGF. These factors were also significantly elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice. Additional moieties including IL-13 were also elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice but not in Cpe fat vs. WT mice. IL-17A mRNA expression was greater in Cpe fat/TNFR1−/− vs. Cpe fat mice and in TNFR1−/− vs. WT mice. Analysis of serum indicated that obesity resulted in systemic as well as pulmonary inflammation, but TNFR1 deficiency had little effect on this systemic inflammation. Our results indicate that TNFR1 is protective against the airway hyperresponsiveness associated with obesity and suggest that effects on pulmonary inflammation may be contributing to this protection.

scholarly journals Distinct Roles of Lymphotoxin α and the Type I Tumor Necrosis Factor (TNF) Receptor in the Establishment of Follicular Dendritic Cells from Non–Bone Marrow–derived Cells

1997 ◽  
Vol 186 (12) ◽  
pp. 1997-2004 ◽  
Author(s):  
Mitsuru Matsumoto ◽  
Yang-Xin Fu ◽  
Hector Molina ◽  
Guangming Huang ◽  
Jinho Kim ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Tumor Necrosis ◽  
Type I ◽  
Follicular Dendritic Cells ◽  
Wild Type ◽  
Lymphotoxin Α ◽  
Deficient Mice ◽  
Necrosis Factor

In mice deficient in either lymphotoxin α (LT-α) or type I tumor necrosis factor receptor (TNFR-I), organized clusters of follicular dendritic cells (FDC) and germinal centers (GC) are absent from the spleen. We investigated the role of LT-α and TNFR-I in the establishment of spleen FDC and GC structure by using reciprocal bone marrow (BM) transfer. When LT-α–deficient mice were reconstituted with wild-type BM, FDC organization and the ability to form GC were restored, indicating that the LT-α–expressing cells required to establish organized FDC are derived from BM. The role of LT-α in establishing organized FDC structure was further investigated by the transfer of complement receptor 1 and 2 (CR1/2)–deficient BM cells into LT-α–deficient mice. Organized FDC were identified with both the FDC-M1 and anti-CR1 monoclonal antibodies in these BM-chimeric mice, indicating that these cells were derived from the LT-α–deficient recipient. Thus, expression of LT-α in the BM-derived cells, but not in the non–BM-derived cells, is required for the maturation of FDC from non-BM precursor cells. In contrast, when TNFR-I–deficient mice were reconstituted with wild-type BM, they showed no detectable FDC clusters or GC formation. This indicates that TNFR-I expression on non–BM-derived cellular components is necessary for the establishment of these lymphoid structures. TNFR-I–deficient BM was able to restore FDC organization and GC formation in LT-α–deficient mice, indicating that formation of these structures does not require TNFR-I expression on BM-derived cells. The data in this study demonstrate that FDC organization and GC formation are controlled by both LT-α–expressing BM-derived cells and by TNFR-I-expressing non–BM-derived cells.

scholarly journals Crucial Role of Tumor Necrosis Factor Receptor 1 Expression on Nonhematopoietic Cells for B Cell Localization within the Splenic White Pulp

1998 ◽  
Vol 187 (4) ◽  
pp. 469-477 ◽  
Author(s):  
Maria Tkachuk ◽  
Stephan Bolliger ◽  
Bernhard Ryffel ◽  
Gerd Pluschke ◽  
Theresa A. Banks ◽  
...  
Keyword(s):  
B Cells ◽  
Tumor Necrosis ◽  
Plasma Cells ◽  
Tumor Necrosis Factor Receptor ◽  
White Pulp ◽  
Splenic White Pulp ◽  
Initial Activation ◽  
Deficient Mice ◽  
Necrosis Factor

During immune responses the initial activation of B cells takes place in T cell zones of periarteriolar lymphoid sheaths (PALS) of the splenic white pulp. After initial activation, B cells migrate into the primary follicles and, in association with follicular dendritic cells (FDCs), undergo clonal expansion and differentiation giving rise to germinal centers (GCs). Peanut agglutinin binding (PNA+) cells of the GC differentiate further into memory or plasma cells. Here we report that in tumor necrosis factor receptor 1–deficient mice (TNFR1−/−), the location of B cells was altered and that plasma cells were abnormally distributed in the splenic PALS. In contrast to lymphotoxin α–deficient mice (LTα−/−), bone marrow or fetal liver transplantation did not correct the abnormal organization of the spleen, location of B cells, the lack of an FDC network, nor the antibody response in TNFR1−/− mice. These results argue for a crucial role of TNFR1 expression on nonhematopoietic cells for the maintenance of the splenic architecture and proper B cell location. In addition, the lack in development of an FDC network after adoptive transfer suggests that either FDCs are not of bone marrow origin or that they depend on signals from nonhematopoietic cells for maturation.

scholarly journals Apparently Normal Tumor Necrosis Factor Receptor 1 Signaling in the Absence of the Silencer of Death Domains

2003 ◽  
Vol 23 (18) ◽  
pp. 6609-6617 ◽  
Author(s):  
Robert Endres ◽  
Georg Häcker ◽  
Inge Brosch ◽  
Klaus Pfeffer
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Receptor ◽  
Death Receptor ◽  
High Dose ◽  
Wild Type ◽  
Induced Apoptosis ◽  
Necrosis Factor

ABSTRACT The silencer of death domains (SODD) has been proposed to prevent constitutive signaling of tumor necrosis factor receptor 1 (TNFR1) in the absence of ligand. Besides TNFR1, death receptor 3 (DR3), Hsp70/Hsc70, and Bcl-2 have been characterized as binding partners of SODD. In order to investigate the in vivo role of SODD, we generated mice congenitally deficient in expression of the sodd gene. No spontaneous inflammatory infiltrations were observed in any organ of these mice. Consistent with this finding, in the absence of SODD no alteration in the activation patterns of nuclear factor κB (NF-κB), stress kinases, or ERK1 or -2 was observed after stimulation with tumor necrosis factor (TNF). Activation of NF-κB by DR3 was also unchanged. The extents of DR3- and TNF-induced apoptosis were comparable in gene-deficient and wild-type cells. Protection of cells against heat shock as mediated by the Hsp70 system and against staurosporine-induced apoptosis was independent of SODD. Furthermore, resistance to high-dose lipopolysaccharide (LPS) injections, LPS-d-GalN injections, and infection with listeriae was similar in wild-type and gene-deficient mice. In conclusion, our data do not support the concept of a unique, nonredundant role of SODD for the functions of TNFR1, Hsp70, and DR3.

scholarly journals Essential Role of Nuclear Factor (NF)-κB–Inducing Kinase and Inhibitor of κb (Iκb) Kinase α in Nf-κb Activation through Lymphotoxin β Receptor, but Not through Tumor Necrosis Factor Receptor I

2001 ◽  
Vol 193 (5) ◽  
pp. 631-636 ◽  
Author(s):  
Akemi Matsushima ◽  
Tsuneyasu Kaisho ◽  
Paul D. Rennert ◽  
Hiroyasu Nakano ◽  
Kyoko Kurosawa ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Essential Role ◽  
Nuclear Factor ◽  
Wild Type ◽  
Embryonic Fibroblasts ◽  
Iκb Kinase ◽  
Β Receptor ◽  
Deficient Mice ◽  
Necrosis Factor

Both nuclear factor (NF)-κB–inducing kinase (NIK) and inhibitor of κB (IκB) kinase (IKK) have been implicated as essential components for NF-κB activation in response to many external stimuli. However, the exact roles of NIK and IKKα in cytokine signaling still remain controversial. With the use of in vivo mouse models, rather than with enforced gene-expression systems, we have investigated the role of NIK and IKKα in signaling through the type I tumor necrosis factor (TNF) receptor (TNFR-I) and the lymphotoxin β receptor (LTβR), a receptor essential for lymphoid organogenesis. TNF stimulation induced similar levels of phosphorylation and degradation of IκBα in embryonic fibroblasts from either wild-type or NIK-mutant mice. In contrast, LTβR stimulation induced NF-κB activation in wild-type mice, but the response was impaired in embryonic fibroblasts from NIK-mutant and IKKα-deficient mice. Consistent with the essential role of IKKα in LTβR signaling, we found that development of Peyer's patches was defective in IKKα-deficient mice. These results demonstrate that both NIK and IKKα are essential for the induction of NF-κB through LTβR, whereas the NIK–IKKα pathway is dispensable in TNFR-I signaling.

scholarly journals Essential Roles of Receptor-Interacting Protein and TRAF2 in Oxidative Stress-Induced Cell Death

2004 ◽  
Vol 24 (13) ◽  
pp. 5914-5922 ◽  
Author(s):  
Han-Ming Shen ◽  
Yong Lin ◽  
Swati Choksi ◽  
Jamie Tran ◽  
Tian Jin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Tumor Necrosis Factor Receptor ◽  
Membrane Lipid ◽  
Critical Event ◽  
Wild Type ◽  
Embryonic Fibroblasts ◽  
Interacting Protein ◽  
Necrosis Factor

ABSTRACT Oxidative stress and reactive oxygen species (ROS) can elicit and modulate various physiological and pathological processes, including cell death. However, the mechanisms controlling ROS-induced cell death are largely unknown. Data from this study suggest that receptor-interacting protein (RIP) and tumor necrosis factor receptor (TNFR)-associated factor 2 (TRAF2), two key effector molecules of TNF signaling, are essential for ROS-induced cell death. We found that RIP−/− or TRAF2−/− mouse embryonic fibroblasts (MEF) are resistant to ROS-induced cell death when compared to wild-type cells, and reconstitution of RIP and TRAF2 gene expression in their respective deficient MEF cells restored their sensitivity to H2O2-induced cell death. We also found that RIP and TRAF2 form a complex upon H2O2 exposure, but without the participation of TNFR1. The colocalization of RIP with a membrane lipid raft marker revealed a possible role of lipid rafts in the transduction of cell death signal initiated by H2O2. Finally, our results demonstrate that activation of c-Jun NH2-terminal kinase 1 is a critical event downstream of RIP and TRAF2 in mediating ROS-induced cell death. Therefore, our study uncovers a novel signaling pathway regulating oxidative stress-induced cell death.

scholarly journals Disruption of the Genes for ClpXP Protease in Salmonella enterica Serovar Typhimurium Results in Persistent Infection in Mice, and Development of Persistence Requires Endogenous Gamma Interferon and Tumor Necrosis Factor Alpha

2001 ◽  
Vol 69 (5) ◽  
pp. 3164-3174 ◽  
Author(s):  
Tomoko Yamamoto ◽  
Hiroshi Sashinami ◽  
Akiko Takaya ◽  
Toshifumi Tomoyasu ◽  
Hidenori Matsui ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Type Strain ◽  
Tumor Necrosis ◽  
Wild Type Strain ◽  
Wild Type ◽  
Necrosis Factor Alpha ◽  
Serovar Typhimurium ◽  
Factor Alpha ◽  
Deficient Mice ◽  
Necrosis Factor

ABSTRACT The enteric pathogen Salmonella enterica serovar Typhimurium, similar to other facultative intracellular pathogens, has been shown to respond to the hostile conditions inside macrophages of the host organism by producing a set of stress proteins that are also induced by various environmental stresses. The stress-induced ClpXP protease is a member of the ATP-dependent proteases, which are known to be responsible for more than 90% of all proteolysis inEscherichia coli. To investigate the contribution of the ClpXP protease to the virulence of serovar Typhimurium we initially cloned the clpP and clpX operon from the pathogenic strain serovar Typhimurium χ3306 and then created insertional mutations in the clpP and/or clpXgene. The ΔclpP and ΔclpX mutants were used to inoculate BALB/c mice by either the intraperitoneal or the oral route and found to be limited in their ability to colonize organs of the lymphatic system and to cause systemic disease in the host. A variety of experiments were performed to determine the possible reasons for the loss of virulence. An oxygen-dependent killing assay using hydrogen peroxide and paraquat (a superoxide anion generator) and a serum killing assay using murine serum demonstrated that all of the serovar Typhimurium ΔclpP and ΔclpX mutants were as resistant to these killing mechanisms as the wild-type strain. On the other hand, the macrophage survival assay revealed that all these mutants were more sensitive to the intracellular environment than the wild-type strain and were unable to grow or survive within peritoneal macrophages of BALB/c mice. In addition, it was revealed that the serovar Typhimurium ClpXP-depleted mutant was not completely cleared but found to persist at low levels within spleens and livers of mice. Interferon gamma-deficient mice and tumor necrosis factor alpha-deficient mice failed to survive the attenuated serovar Typhimurium infections, suggesting that both endogenous cytokines are essential for regulation of persistent infection with serovar Typhimurium.

scholarly journals Delayed Mortality and Attenuated Thrombocytopenia Associated with Severe Malaria in Urokinase- and Urokinase Receptor-Deficient Mice

2000 ◽  
Vol 68 (7) ◽  
pp. 3822-3829 ◽  
Author(s):  
Pierre Francois Piguet ◽  
Chen Da Laperrousaz ◽  
Christian Vesin ◽  
Fabienne Tacchini-Cottier ◽  
Giorgio Senaldi ◽  
...  
Keyword(s):  
Severe Malaria ◽  
Plasminogen Activators ◽  
Tissue Type ◽  
Mrna Levels ◽  
Wild Type ◽  
Upa Receptor ◽  
Delayed Mortality ◽  
Deficient Mice ◽  
Necrosis Factor

ABSTRACT We explored the role of urokinase and tissue-type plasminogen activators (uPA and tPA), as well as the uPA receptor (uPAR; CD87) in mouse severe malaria (SM), using genetically deficient (−/−) mice. The mortality resulting from Plasmodium berghei ANKA infection was delayed in uPA−/− and uPAR−/−mice but was similar to that of the wild type (+/+) in tPA−/− mice. Parasitemia levels were similar in uPA−/−, uPAR−/−, and +/+ mice. Production of tumor necrosis factor, as judged from the plasma level and the mRNA levels in brain and lung, was markedly increased by infection in both +/+ and uPAR−/− mice. Breakdown of the blood-brain barrier, as evidenced by the leakage of Evans Blue, was similar in +/+ and uPAR−/− mice. SM was associated with a profound thrombocytopenia, which was attenuated in uPA−/− and uPAR−/− mice. Administration of aprotinin, a plasmin antagonist, also delayed mortality and attenuated thrombocytopenia. Platelet trapping in cerebral venules or alveolar capillaries was evident in +/+ mice but absent in uPAR−/− mice. In contrast, macrophage sequestration in cerebral venules or alveolar capillaries was evident in both +/+ and uPAR−/− mice. Polymorphonuclear leukocyte sequestration in alveolar capillaries was similar in +/+ and uPAR−/− mice. These results demonstrate that the uPAR deficiency attenuates the severity of SM, probably by its important role in platelet kinetics and trapping. These results therefore suggest that platelet sequestration contributes to the pathogenesis of SM.

Physiological and cytokine responses in IL-1 beta-deficient mice after zymosan-induced inflammation

1997 ◽  
Vol 273 (1) ◽  
pp. R400-R406 ◽  
Author(s):  
G. Fantuzzi ◽  
S. Sacco ◽  
P. Ghezzi ◽  
C. A. Dinarello
Keyword(s):  
Lavage Fluid ◽  
Inhibitory Effect ◽  
Tnf Alpha ◽  
Wild Type ◽  
Cytokine Responses ◽  
Alpha Production ◽  
Fluid Levels ◽  
Deficient Mice ◽  
Necrosis Factor

Interleukin (IL)-1 beta-deficient (IL-1 beta -/-) mice exhibited decreased zymosan-induced lethality and reduced production of IL-6 compared with wild-type controls (IL-1 beta +/+). In addition, IL-1 beta -/- mice had a diminished cellular infiltrate (33%) in the peritoneal cavity after zymosan. However, anorexia and hypoglycemia were not affected by the lack of IL-1 beta. The induction of corticosterone was only slightly reduced (14%) in IL-1 beta -/- mice. Peritoneal lavage fluid levels for IL-1 alpha, but not for tumor necrosis factor (TNF)-alpha, were also decreased. To evaluate the role of residual IL-1 alpha production in IL-1 beta -/- mice, we used IL-1-receptor antagonist (IL-1ra). In IL-1 beta +/+ mice, IL-1ra inhibited production of IL-6 after zymosan, without affecting TNF-alpha synthesis. There was no further inhibitory effect of IL-1ra on IL-6 production in IL-1 beta -/- mice, suggesting no role for IL-1 alpha in zymosan-induced IL-6. Our results demonstrate that IL-1 beta plays a significant, although not exclusive, role in the physiological and cytokine responses to zymosan-mediated inflammation.

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