scholarly journals The ubiquitin ligase HOIL-1L regulates immune responses by interacting with linear ubiquitin chains

2021 ◽  
Author(s):  
Carlos Gomez Diaz ◽  
Gustav Jonsson ◽  
Katrin Schodl ◽  
Luiza Deszcz ◽  
Annika Bestehorn ◽  
...  

The Linear Ubiquitin Assembly Complex (LUBAC), composed of HOIP, HOIL-1L and SHARPIN, promotes Tumor Necrosis Factor (TNF)-dependent NF-kB signaling in diverse cell types. HOIL-1L contains an Npl4 Zinc Finger (NZF) domain that specifically recognizes linear ubiquitin chains, but its physiological role in vivo has remained unclear. Here, we demonstrate that the HOIL-1L NZF domain has important regulatory functions in inflammation and immune responses in mice. We generated knockin mice (Hoil-1lT20;A;R208A/T201A;R208A) expressing a HOIL-1L NZF mutant, and observed attenuated responses to TNF- and LPS-induced shock, including prolonged survival, stabilized body temperature, reduced cytokine production and liver damage markers. Cells derived from the HOIL-1L knockin mice show reduced TNF-dependent NF-kB activation and incomplete recruitment of HOIL-1L into TNF Receptor (TNFR) Complex I. We further show that the HOIL-1L-NZF domain cooperates with SHARPIN to prevent TNFR-dependent skin inflammation. Collectively, our data suggest that linear ubiquitin-chain binding by HOIL-1L regulates immune responses and inflammation in vivo.

1997 ◽  
Vol 186 (7) ◽  
pp. 999-1014 ◽  
Author(s):  
Hideaki Ishikawa ◽  
Daniel Carrasco ◽  
Estefania Claudio ◽  
Rolf-Peter Ryseck ◽  
Rodrigo Bravo

The nfkb2 gene encodes the p100 precursor which produces the p52 protein after proteolytic cleavage of its COOH-terminal domain. Although the p52 product can act as an alternative subunit of NF-κB, the p100 precursor is believed to function as an inhibitor of Rel/NF-κB activity by cytoplasmic retention of Rel/NF-κB complexes, like other members of the IκB family. However, the physiological relevance of the p100 precursor as an IκB molecule has not been understood. To assess the role of the precursor in vivo, we generated, by gene targeting, mice lacking p100 but still containing a functional p52 protein. Mice with a homozygous deletion of the COOH-terminal ankyrin repeats of NF-κB2 (p100−/−) had marked gastric hyperplasia, resulting in early postnatal death. p100−/− animals also presented histopathological alterations of hematopoietic tissues, enlarged lymph nodes, increased lymphocyte proliferation in response to several stimuli, and enhanced cytokine production in activated T cells. Dramatic induction of nuclear κB–binding activity composed of p52-containing complexes was found in all tissues examined and also in stimulated lymphocytes. Thus, the p100 precursor is essential for the proper regulation of p52-containing Rel/NF-κB complexes in various cell types and its absence cannot be efficiently compensated for by other IκB proteins.


2021 ◽  
Author(s):  
Andrew D. Beale ◽  
Priya Crosby ◽  
Utham K. Valekunja ◽  
Rachel S. Edgar ◽  
Johanna E. Chesham ◽  
...  

AbstractCellular circadian rhythms confer daily temporal organisation upon behaviour and physiology that is fundamental to human health and disease. Rhythms are present in red blood cells (RBCs), the most abundant cell type in the body. Being naturally anucleate, RBC circadian rhythms share key elements of post-translational, but not transcriptional, regulation with other cell types. The physiological function and developmental regulation of RBC circadian rhythms is poorly understood, however, partly due to the small number of appropriate techniques available. Here, we extend the RBC circadian toolkit with a novel biochemical assay for haemoglobin oxidation status, termed “Bloody Blotting”. Our approach relies on a redox-sensitive covalent haem-haemoglobin linkage that forms during cell lysis. Formation of this linkage exhibits daily rhythms in vitro, which are unaffected by mutations that affect the timing of circadian rhythms in nucleated cells. In vivo, haemoglobin oxidation rhythms demonstrate daily variation in the oxygen-carrying and nitrite reductase capacity of the blood, and are seen in human subjects under controlled laboratory conditions as well as in freely-behaving humans. These results extend our molecular understanding of RBC circadian rhythms and suggest they serve an important physiological role in gas transport.


2017 ◽  
Vol 8 (2) ◽  
pp. e2608-e2608 ◽  
Author(s):  
Hongfeng Yuan ◽  
Brandon Tan ◽  
Shou-Jiang Gao

Abstract Tenovin-6 has attracted significant interest because it activates p53 and inhibits sirtuins. It has anti-neoplastic effects on multiple hematopoietic malignancies and solid tumors in both in vitro and in vivo studies. Tenovin-6 was recently shown to impair the autophagy pathway in chronic lymphocytic leukemia cells and pediatric soft tissue sarcoma cells. However, whether tenovin-6 has a general inhibitory effect on autophagy and whether there is any involvement with SIRT1 and p53, both of which are regulators of the autophagy pathway, remain unclear. In this study, we have demonstrated that tenovin-6 increases microtubule-associated protein 1 light chain 3 (LC3-II) level in diverse cell types in a time- and dose-dependent manner. Mechanistically, the increase of LC3-II by tenovin-6 is caused by inhibition of the classical autophagy pathway via impairing lysosomal function without affecting the fusion between autophagosomes and lysosomes. Furthermore, we have revealed that tenovin-6 activation of p53 is cell type dependent, and tenovin-6 inhibition of autophagy is not dependent on its regulatory functions on p53 and SIRT1. Our results have shown that tenovin-6 is a potent autophagy inhibitor, and raised the precaution in interpreting results where tenovin-6 is used as an inhibitor of SIRT1.


Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1607-1613 ◽  
Author(s):  
W Digel ◽  
W Schoniger ◽  
M Stefanic ◽  
H Janssen ◽  
C Buck ◽  
...  

Abstract Recombinant tumor necrosis factor-alpha (TNF-alpha) is a cytokine that induces proliferation of neoplastic B cells from patients with chronic lymphocytic leukemia (CLL). To gain insight into the mechanisms involved in regulating TNF responsiveness, we have examined TNF receptor expression on neoplastic B-CLL cells. We have demonstrated that freshly isolated neoplastic B cells from patients with CLL did not express TNF receptors. After 1 day of incubation in culture medium, TNF receptors were detectable in the range of 540 to 1,500/cell. Kinetic experiments revealed that receptor expression was half-maximal after 3 hours of culturing and required de novo protein synthesis. The Scatchard plots of TNF-alpha binding indicated a single set of high- affinity TNF receptors with a dissociation constant of 70 pmol/L. TNF receptor expression in vitro was found in all examined cases. All cytokines tested, with the exception of IL-2, did not influence the expression of TNF receptors. The TNF receptor expression is enhanced in B-CLL cells cultured in the presence of interleukin-2 when compared with the receptor expression of cells cultured in medium alone. Our data suggest that neoplastic B-CLL cells in patients with stable disease do not express TNF receptors in vivo and that an unknown mechanism suppressing TNF receptor expression in vivo may play a role in growth regulation of neoplastic B cells.


2004 ◽  
Vol 78 (21) ◽  
pp. 11641-11647 ◽  
Author(s):  
Hong He ◽  
Ronald J. Messer ◽  
Shimon Sakaguchi ◽  
Guojun Yang ◽  
Shelly J. Robertson ◽  
...  

ABSTRACT Chronic infection with Friend retrovirus is associated with suppressed antitumor immune responses. In the present study we investigated whether modulation of T-cell responses during acute infection would restore antitumor immunity in persistently infected mice. T-cell modulation was done by treatments with DTA-1 anti- glucocorticoid-induced tumor necrosis factor receptor monoclonal antibodies. The DTA-1 monoclonal antibody is nondepleting and delivers costimulatory signals that both enhance the activation of effector T cells and inhibit suppression by regulatory T cells. DTA-1 therapy produced faster Th1 immune responses, significant reductions in both acute virus loads and pathology and, most importantly, long-term improvement of CD8+ T-cell-mediated antitumor responses.


1975 ◽  
Vol 8 (4) ◽  
pp. 507-522
Author(s):  
Sirkka Kontiainen ◽  
O. Mäkelä ◽  
M. Hurme

Several functions of the animal body can take place in cell or tissue cultures with almost unreduced efficiency and precision. Functions, where only one cell type is involved, often do so, but also some differentiation steps where interactions between two or more cell types are clearly needed can take place in tissue culture (Saxén et al. 1968).Most immune responses require collaboration between two or more cell types (Claman, Chaperon & Triplett, 1966; Miller & Mitchell, 1968; Feldmann & Nossal 1972c). Some of them can be easily induced in vitro but others cannot. Even when antibody responses can be induced in vitro their intensity varies a great deal. With some antigens and under some circumstances a response in vitro can be nearly as strong as one in vivo. A crude comparison can be derived from responses in vitro and in vivo to the same antigen, conjugate of hapten NIP and pneumococcal polysaccharide type III (NIP-SIll, Nakamura, Ray & Mäkelä, 1973).


2003 ◽  
Vol 50 (3) ◽  
pp. 613-624 ◽  
Author(s):  
Dariusz W Kowalczyk ◽  
Piotr J Wysocki ◽  
Andrzej Mackiewicz

The ability of various cytokines to hamper tumor growth or to induce anti-tumor immune response has resulted in their study as antitumor agents in gene therapy approaches. In this review we will concentrate on the costimulation of antitumor immune responses using modification of various cell types by cytokine genes. Several strategies have emerged such as (i). modification of tumor cells with cytokine genes ex vivo (whole tumor cell vaccines), (ii). ex vivo modification of other cell types for cytokine gene delivery, (iii). delivery of cytokine genes into tumor microenvironment in vivo, (iv). modification of dendritic cells with cytokine genes ex vivo. Originally single cytokine genes were used. Subsequently, multiple cytokine genes were applied simultaneously, or in combination with other factors such as chemokines, membrane bound co-stimulatory molecules, or tumor associated antigens. In this review we discuss these strategies and their use in cancer treatment as well as the promises and limitations of cytokine based cancer gene therapy. Clinical trials, including our own experience, employing the above strategies are discussed.


2021 ◽  
Author(s):  
Amada D. Caliz ◽  
Hyung-Jin Yoo ◽  
Anastassiia Vertii ◽  
Cathy Tournier ◽  
Roger J. Davis ◽  
...  

Mitogen kinase kinase 4 (MKK4) and Mitogen kinase kinase 7 (MKK7) are members of the MAP2K family which can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both, c-Jun N-terminal Kinase (JNK) and p38 MAPK, whereas MKK7 only activates JNK in response to different stimuli. The stimuli as well as cell type determine the choice of MAP2K member that mediates the response. In a variety of cell types, the MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK7 and MKK4 contributes to innate immune response in macrophages as well as during inflammation in vivo. To address this question and elucidate the role of MKK7 and MKK4 in macrophage and in vivo, we developed MKK7- and MKK4-deficient mouse models with tamoxifen-inducible Rosa26 CreERT. This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for LPS induced cytokine production and migration which appears to be a major contributor to the inflammatory response in vivo. Whereas MKK4 plays a significant but minor role in cytokine production in vivo.


Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5624-5637 ◽  
Author(s):  
Akhilesh K. Tamrakar ◽  
Jonathan D. Schertzer ◽  
Tim T. Chiu ◽  
Kevin P. Foley ◽  
Philip J. Bilan ◽  
...  

Insulin resistance is associated with chronic low-grade inflammation in vivo, largely mediated by activated innate immune cells. Cytokines and pathogen-derived ligands of surface toll-like receptors can directly cause insulin resistance in muscle cells. However, it is not known if intracellular pathogen sensors can, on their own, provoke insulin resistance. Here, we show that the cytosolic pattern recognition receptors nucleotide-binding oligomerization domain-containing protein (NOD)1 and NOD2 are expressed in immune and metabolic tissues and hypothesize that their activation in muscle cells would result in cell-autonomous responses leading to insulin resistance. Bacterial peptidoglycan motifs that selectively activate NOD2 were directly administered to L6- GLUT4myc myotubes in culture. Within 3 h, insulin resistance arose, characterized by reductions in each insulin-stimulated glucose uptake, GLUT4 translocation, Akt Ser473 phosphorylation, and insulin receptor substrate 1 tyrosine phosphorylation. Muscle cell-autonomous responses to NOD2 ligand included activation of the stress/inflammation markers c-Jun N-terminal kinase, ERK1/2, p38 MAPK, degradation of inhibitor of κBα, and production of proinflammatory cytokines. These results show that NOD2 alone is capable of acutely inducing insulin resistance within muscle cells, possibly by activating endogenous inflammatory signals and/or through cytokine production, curbing upstream insulin signals. NOD2 is hence a new inflammation target connected to insulin resistance, and this link occurs without the need of additional contributing cell types. This study provides supporting evidence for the integration of innate immune and metabolic responses through the involvement of NOD proteins and suggests the possible participation of cell autonomous immune responses in the development of insulin resistance in skeletal muscle, the major depot for postprandial glucose utilization.


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