scholarly journals Toxoplasma gondii Infection of Neurons Induces Neuronal Cytokine and Chemokine Production, but Gamma Interferon- and Tumor Necrosis Factor-Stimulated Neurons Fail To Inhibit the Invasion and Growth of T. gondii

2001 ◽  
Vol 69 (12) ◽  
pp. 7889-7893 ◽  
Author(s):  
D. Schlüter ◽  
M. Deckert ◽  
H. Hof ◽  
K. Frei
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Transforming Growth Factor ◽  
Interleukin 1 ◽  
Gamma Interferon ◽  
Chemokine Production ◽  
Ifn Γ ◽  
Tgf Β1 ◽  
Necrosis Factor

ABSTRACT The intracellular parasite Toxoplasma gondii has the capacity to persist in the brain within neurons. In this study we demonstrated that T. gondiiinfected murine cerebellar neurons in vitro and replicated within these cells. Stimulation with gamma interferon (IFN-γ) and/or tumor necrosis factor (TNF) did not enable neurons to inhibit parasite invasion and replication. Cultured neurons constitutively produced interleukin 1 (IL-1), IL-6, macrophage inflammatory protein 1α (MIP-1α), and MIP-1β but not transforming growth factor β1 (TGF-β1), IL-10, and granulocyte-macrophage colony-stimulating factor. Neuronal expression of some cytokines (IL-6, TGF-β1) and chemokines (MIP-1β) was regulated by infection and/or by IFN-γ and TNF.

scholarly journals Gamma Interferon Augments Macrophage Activation by Lipopolysaccharide by Two Distinct Mechanisms, at the Signal Transduction Level and via an Autocrine Mechanism Involving Tumor Necrosis Factor Alpha and Interleukin-1

1999 ◽  
Vol 67 (1) ◽  
pp. 206-212 ◽  
Author(s):  
Thomas K. Held ◽  
Xiao Weihua ◽  
Liang Yuan ◽  
Dhananjaya V. Kalvakolanu ◽  
Alan S. Cross
Keyword(s):  
Nitric Oxide ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Gamma Interferon ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT When given in the presence of gamma interferon (IFN-γ), otherwise nontoxic doses of lipopolysaccharide (LPS or endotoxin) become highly lethal for mice. The mechanisms of this synergistic toxicity are not known. We considered the possibility that an interaction between the LPS-induced NF-κB and IFN-γ-induced JAK-STAT pathways at the pretranscriptional level may enhance the LPS-induced signals. To test this hypothesis, we incubated murine macrophage RAW 264.7 cells with IFN-γ for 2 h before addition of different doses of LPS. Consistent with the synergistic induction of inducible nitric oxide synthase mRNA and nitric oxide production by a combination of LPS and IFN-γ, IFN-γ strongly augmented LPS-induced NF-κB activation and accelerated the binding of NF-κB to DNA to as early as 5 min. In agreement with this, IFN-γ pretreatment promoted rapid degradation of IκB-α but not that of IκB-β. Inhibition of protein synthesis during IFN-γ treatment suppressed LPS-initiated NF-κB binding. A rapidly induced protein appeared to be involved in IFN-γ priming. Preincubation of cells with antibodies to tumor necrosis factor alpha or the interleukin-1 receptor partially reduced the priming effect of IFN-γ. In a complementary manner, LPS enhanced the activation of signal-transducing activator of transcription 1 by IFN-γ. These data suggest novel mechanisms for the synergy between IFN-γ and LPS by which they cross-regulate the signal-transducing molecules. Through this mechanism, IFN-γ may transform a given dose of LPS into a lethal stimulus capable of causing sepsis. It may also serve a beneficial purpose by enabling the host to respond quickly to relatively low doses of LPS and thereby activating antibacterial defenses.

scholarly journals Splenectomy improves liver fibrosis via tumor necrosis factor superfamily 14 (LIGHT) through the JNK/TGF-β1 signaling pathway

2021 ◽  
Author(s):  
Qing-shan Liang ◽  
Jian-Gang Xie ◽  
ChaoPing Yu ◽  
ZhuSheng Feng ◽  
JingChang Ma ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Liver Fibrosis ◽  
Tumor Necrosis ◽  
Transforming Growth Factor ◽  
Jnk Signaling ◽  
Hepatic Macrophages ◽  
Tumor Necrosis Factor Superfamily ◽  
Tgf Β1 ◽  
Necrosis Factor

AbstractSplenectomy has been reported to improve liver fibrosis in patients with cirrhosis and hypersplenism. However, the mechanisms remain unclear. Tumor necrosis factor superfamily 14 (TNFSF14; also known as LIGHT) is highly expressed in the context of fibrosis and promotes disease progression in patients with fibrotic diseases such as pulmonary and skin fibrosis. Here, we determined whether splenectomy controls the production of LIGHT to improve liver fibrosis. Splenectomy reduced serum LIGHT levels in cirrhotic patients with hypersplenism and a ConA-induced liver fibrosis mouse model. Blocking LIGHT resulted in the downregulation of TGF-β1 in RAW264.7 cells. LIGHT treatment of RAW264.7 and JS1 cells in coculture regulated transforming growth factor-β1 (TGF-β1) expression through the activation of JNK signaling. Small interfering RNA-mediated silencing of lymphotoxin β receptor (LTβR) in macrophages resulted in pronounced decreases in the levels of fibrosis and αSMA in JS1 cells. These results indicated that LIGHT bound to LTβR and drove liver fibrosis in vitro. Blocking TGF-β1 abolished the effect of LIGHT in vitro. Furthermore, the administration of recombinant murine LIGHT protein-induced liver fibrosis with splenectomy, while blocking LIGHT without splenectomy improved liver fibrosis in vivo, revealing that the decrease in fibrosis following splenectomy was directly related to reduced levels of LIGHT. Thus, high levels of LIGHT derived from the spleen and hepatic macrophages activate JNK signaling and lead to increased TGF-β1 production in hepatic macrophages. Splenectomy attenuates liver fibrosis by decreasing the expression of LIGHT.

scholarly journals Gamma Interferon and Lipopolysaccharide Interact at the Level of Transcription To Induce Tumor Necrosis Factor Alpha Expression

2001 ◽  
Vol 69 (5) ◽  
pp. 2847-2852 ◽  
Author(s):  
Julia Y. Lee ◽  
Kathleen E. Sullivan
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Gamma Interferon ◽  
Necrosis Factor Alpha ◽  
Rnase Protection ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Lipopolysaccharide (LPS) is a very potent inducer of tumor necrosis factor alpha (TNF-α) expression from monocytes and macrophages. Another inflammatory cytokine, gamma interferon (IFN-γ), can potentiate the effects of LPS, but the mechanism is not thoroughly understood. Previous reports emphasized the ability of IFN-γ to upregulate CD14 expression (the receptor for LPS), and nearly all studies have utilized sequential stimulation with IFN-γ followed by LPS to exploit this phenomenon. This study demonstrates that IFN-γ can upregulate the effect of LPS at the level of transcription. Human monoblastic Mono-Mac-6 cells produced up to threefold-greater levels of TNF-α when simultaneously stimulated with LPS and IFN-γ compared to treatment with LPS alone. RNase protection studies showed a similar increase in RNA beginning as early as within 30 min. The synthesis of TNF-α mRNA in IFN-γ- and LPS-treated Mono-Mac-6 cells was also temporally prolonged even though the message turnover rate was identical to that seen in LPS stimulated cells. The modulatory effect of IFN-γ may be mediated by Jak2.

In Vitro Sensitivity of Three Human Renal Tumor Xenografts Towards Tumor Necrosis Factor and Alpha and Gamma Interferon

1989 ◽  
pp. 30-38 ◽  
Author(s):  
A. J. M. C. Beniers ◽  
R. J. A. Van Moorselaar ◽  
W. P. Peelen ◽  
B. T. Hendriks ◽  
U. Otto ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Renal Tumor ◽  
Gamma Interferon ◽  
Tumor Xenografts ◽  
In Vitro Sensitivity ◽  
Necrosis Factor

scholarly journals Gamma-interferon and tumor necrosis factor production after bone marrow transplantation is augmented by exposure to marrow fibroblasts infected with cytomegalovirus

Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 1046-1053 ◽  
Author(s):  
AS Duncombe ◽  
A Meager ◽  
HG Prentice ◽  
JE Grundy ◽  
HE Heslop ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Transplantation ◽  
Tumor Necrosis Factor ◽  
Marrow Transplantation ◽  
Tumor Necrosis ◽  
Gamma Interferon ◽  
Cmv Infection ◽  
Necrosis Factor

Abstract After bone marrow transplantation (BMT), mortality from viral infections such as cytomegalovirus (CMV) remains high. Gamma-Interferon (gamma IFN) and tumor necrosis factor (TNF) are produced constitutively after BMT and have anti-viral properties. To study the effects of these cytokines on CMV interaction with host cells, we have used patient marrow fibroblasts since marrow stroma is a target for CMV infection correlating with myelosuppression in vivo. Both gamma IFN and TNF are constitutively produced by recipient CD3+ and CD16+ lymphocytes, but not by their marrow fibroblasts. Secretion by peripheral blood mononuclear cells is increased if they are cultured with host fibroblasts infected with CMV in vitro and the levels of gamma IFN and TNF produced are within the range that protects fresh fibroblasts from CMV infection. Constitutive secretion of cytokines by lymphocytes declines by 8 weeks after BMT, a time when the risk of CMV disease increases sharply. The in vitro phenomenon that we have described needs to be evaluated in correlative studies on individual BMT recipients to determine whether such a cytokine-mediated defense mechanism against CMV may operate in vivo.

Interleukin-1 and tumor necrosis factor stimulate the formation of human osteoclastlike cells in vitro

2009 ◽  
Vol 4 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Johannes Pfeilschifter ◽  
Chantal Chenu ◽  
Andrew Bird ◽  
Gregory R. Mundy ◽  
David G. Roodman
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Necrosis Factor
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