scholarly journals Tumor Necrosis Factor (TNF) Receptor Shedding Controls Thresholds of Innate Immune Activation That Balance Opposing TNF Functions in Infectious and Inflammatory Diseases

2004 ◽  
Vol 200 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Sofia Xanthoulea ◽  
Manolis Pasparakis ◽  
Stavroula Kousteni ◽  
Cord Brakebusch ◽  
David Wallach ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Bacterial Infections ◽  
Tumor Necrosis ◽  
Inflammatory Responses ◽  
Endotoxic Shock ◽  
Innate Immune ◽  
Disease Assessment ◽  
Recurrent Fever ◽  
Receptor Shedding ◽  
Necrosis Factor

Tumor necrosis factor (TNF) is a potent cytokine exerting critical functions in the activation and regulation of immune and inflammatory responses. Due to its pleiotropic activities, the amplitude and duration of TNF function must be tightly regulated. One of the mechanisms that may have evolved to modulate TNF function is the proteolytic cleavage of its cell surface receptors. In humans, mutations affecting shedding of the p55TNF receptor (R) have been linked with the development of the TNFR-associated periodic syndromes, disorders characterized by recurrent fever attacks and localized inflammation. Here we show that knock-in mice expressing a mutated nonsheddable p55TNFR develop Toll-like receptor–dependent innate immune hyperreactivity, which renders their immune system more efficient at controlling intracellular bacterial infections. Notably, gain of function for antibacterial host defenses ensues at the cost of disbalanced inflammatory reactions that lead to pathology. Mutant mice exhibit spontaneous hepatitis, enhanced susceptibility to endotoxic shock, exacerbated TNF-dependent arthritis, and experimental autoimmune encephalomyelitis. These results introduce a new concept for receptor shedding as a mechanism setting up thresholds of cytokine function to balance resistance and susceptibility to disease. Assessment of p55TNFR shedding may thus be of prognostic value in infectious, inflammatory, and autoimmune diseases.

scholarly journals Revisiting TNF Receptor-Associated Periodic Syndrome (TRAPS): Current Perspectives

2020 ◽  
Vol 21 (9) ◽  
pp. 3263 ◽  
Author(s):  
Cornelia Cudrici ◽  
Natalie Deuitch ◽  
Ivona Aksentijevich
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Inflammatory Responses ◽  
Treatment Options ◽  
Tumor Necrosis Factor Receptor ◽  
Periodic Syndrome ◽  
Pathogenic Variants ◽  
Tnfrsf1a Gene ◽  
Receptor Shedding ◽  
Necrosis Factor

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal dominant autoinflammatory syndrome characterized by prolonged and recurrent episodes of fever, abdominal and/or chest pain, arthralgia, myalgia, and erythematous rash. TRAPS is associated with heterozygous variants in the TNFRSF1A gene, which encodes the TNFR1 (tumor necrosis factor receptor 1) receptor. Disease-causing variants are found exclusively in the extracellular domain of TNFR1 and affect receptor structure and binding to the TNF ligand. The precise mechanism of the disease is still unclear, but it is thought that intracellular accumulation of misfolded mutant protein leads to endoplasmic reticulum stress and enhanced inflammatory responses through constitutive activation of various immune pathways. Other possible mechanisms contributing to the disease pathogenesis include defective receptor shedding, TNF-induced cell death, production of reactive oxygen species, and autophagy impairment. Patients’ leucocytes are hyperresponsive to stimulation and produce elevated levels of proinflammatory cytokines. Systemic autoimmune (AA) amyloidosis is an important cause of morbidity and mortality in TRAPS. Over the last two decades, new therapies have changed the progression and outcome of the disease. In this review, we summarize clinical data from 209 patients with validated pathogenic variants reported in the literature and discuss TRAPS diagnosis, pathogenesis, and treatment options.

Tumor Necrosis Factor Alpha Converting Enzyme (TACE) as Possible Therapeutic Target in SARS-CoV-2 Induced Acute Respiratory Distress Syndrome (ARDS)

2020 ◽  
Author(s):  
Joao Batista Junior
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Inflammatory Responses ◽  
Converting Enzyme ◽  
Necrosis Factor Alpha ◽  
Tace Inhibitors ◽  
Factor Alpha ◽  
Activity State ◽  
Necrosis Factor

<div>This study reveals, for the first time, that rosiglitazone and pioglitazone, two thiazolidinedione drugs already approved as therapeutic agents to treat type II diabetes, were found to bind favorably to tumor necrosis factor alpha converting enzyme catalytic site with highlighted binding features.</div><div><br></div>This study suggests that rosiglitazone and pioglitazone, acting as TACE inhibitors agents might avoid or attenuate the hyperexcitability proteolytic activity state of TACE, represent a new potential therapeutic approach to treat SARS-CoV-2 infection-associated severe systemic inflammatory responses observed among severely or critically ill SARS-CoV-2 patients and, consequently, to diminish severe inflammatory‐induced lung injury, ARDS development and death rates.<br><br>

scholarly journals Protective effect of chlorpromazine on endotoxin toxicity and TNF production in glucocorticoid-sensitive and glucocorticoid-resistant models of endotoxic shock.

1991 ◽  
Vol 173 (6) ◽  
pp. 1305-1310 ◽  
Author(s):  
M Gadina ◽  
R Bertini ◽  
M Mengozzi ◽  
M Zandalasini ◽  
A Mantovani ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Actinomycin D ◽  
Protective Action ◽  
Endotoxic Shock ◽  
Serum Levels ◽  
Inhibitory Effect ◽  
Protective Agent ◽  
Initial Correlations ◽  
Necrosis Factor

The present study was designed to define the potential of chlorpromazine (CPZ) as a protective agent against lipopolysaccharide (LPS) toxicity in comparison with glucocorticoids, and to obtain initial correlations with its effects on the levels of tumor necrosis factor (TNF), a pivotal mediator of endotoxic shock. It was found that CPZ protects mice, normal or adrenalectomized, and guinea pigs against lethality of LPS, and inhibited TNF serum levels, like dexamethasone (DEX), a well-known inhibitor of TNF synthesis. CPZ protected against LPS lethality when administered 30 minutes (min) before, simultaneously, or up to 10 min after LPS and was ineffective when given 30 min after LPS, paralleling the inhibitory effect on TNF production. In another experimental model, where mice were sensitized to LPS toxicity by actinomycin D, CPZ significantly inhibited LPS lethality and hepatotoxicity, whereas under these conditions DEX was inactive. These experiments indicate that CPZ has a protective action in both glucocorticoid-sensitive and -resistant models of endotoxic shock.

scholarly journals Human Immunodeficiency Virus Infection Alters Tumor Necrosis Factor Alpha Production via Toll-Like Receptor-Dependent Pathways in Alveolar Macrophages and U1 Cells

2008 ◽  
Vol 82 (16) ◽  
pp. 7790-7798 ◽  
Author(s):  
Marlynne Q. Nicol ◽  
Jean-Marie Mathys ◽  
Albertina Pereira ◽  
Kevin Ollington ◽  
Michael H. Ieong ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Innate Immune ◽  
Hiv Positive ◽  
Toll Like Receptor ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Immunodeficiency Virus ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Human immunodeficiency virus (HIV)-positive persons are predisposed to pulmonary infections, even after receiving effective highly active antiretroviral therapy. The reasons for this are unclear but may involve changes in innate immune function. HIV type 1 infection of macrophages impairs effector functions, including cytokine production. We observed decreased constitutive tumor necrosis factor alpha (TNF-α) concentrations and increased soluble tumor necrosis factor receptor type II (sTNFRII) in bronchoalveolar lavage fluid samples from HIV-positive subjects compared to healthy controls. Moreover, net proinflammatory TNF-α activity, as measured by the TNF-α/sTNFRII ratio, decreased as HIV-related disease progressed, as manifested by decreasing CD4 cell count and increasing HIV RNA (viral load). Since TNF-α is an important component of the innate immune system and is produced upon activation of Toll-like receptor (TLR) pathways, we hypothesized that the mechanism associated with deficient TNF-α production in the lung involved altered TLR expression or a deficit in the TLR signaling cascade. We found decreased Toll-like receptor 1 (TLR1) and TLR4 surface expression in HIV-infected U1 monocytic cells compared to the uninfected parental U937 cell line and decreased TLR message in alveolar macrophages (AMs) from HIV-positive subjects. In addition, stimulation with TLR1/2 ligand (Pam3Cys) or TLR4 ligand (lipopolysaccharide) resulted in decreased intracellular phosphorylated extracellular signal-regulated kinase and subsequent decreased transcription and expression of TNF-α in U1 cells compared to U937 cells. AMs from HIV-positive subjects also showed decreased TNF-α production in response to these TLR2 and TLR4 ligands. We postulate that HIV infection alters expression of TLRs with subsequent changes in mitogen-activated protein kinase signaling and cytokine production that ultimately leads to deficiencies of innate immune responses that predispose HIV-positive subjects to infection.

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