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Massa C, Wang Y, Marr N, Seliger B. Interferons and Resistance Mechanisms in Tumors and Pathogen-Driven Diseases—Focus on the Major Histocompatibility Complex (MHC) Antigen Processing Pathway. Int J Mol Sci 2023; 24:ijms24076736. [PMID: 37047709 PMCID: PMC10095295 DOI: 10.3390/ijms24076736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/22/2023] [Accepted: 02/25/2023] [Indexed: 04/08/2023] Open
Abstract
Interferons (IFNs), divided into type I, type II, and type III IFNs represent proteins that are secreted from cells in response to various stimuli and provide important information for understanding the evolution, structure, and function of the immune system, as well as the signaling pathways of other cytokines and their receptors. They exert comparable, but also distinct physiologic and pathophysiologic activities accompanied by pleiotropic effects, such as the modulation of host responses against bacterial and viral infections, tumor surveillance, innate and adaptive immune responses. IFNs were the first cytokines used for the treatment of tumor patients including hairy leukemia, renal cell carcinoma, and melanoma. However, tumor cells often develop a transient or permanent resistance to IFNs, which has been linked to the escape of tumor cells and unresponsiveness to immunotherapies. In addition, loss-of-function mutations in IFN signaling components have been associated with susceptibility to infectious diseases, such as COVID-19 and mycobacterial infections. In this review, we summarize general features of the three IFN families and their function, the expression and activity of the different IFN signal transduction pathways, and their role in tumor immune evasion and pathogen clearance, with links to alterations in the major histocompatibility complex (MHC) class I and II antigen processing machinery (APM). In addition, we discuss insights regarding the clinical applications of IFNs alone or in combination with other therapeutic options including immunotherapies as well as strategies reversing the deficient IFN signaling. Therefore, this review provides an overview on the function and clinical relevance of the different IFN family members, with a specific focus on the MHC pathways in cancers and infections and their contribution to immune escape of tumors.
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Affiliation(s)
- Chiara Massa
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
| | - Yuan Wang
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
| | - Nico Marr
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha P.O. Box 34110, Qatar
| | - Barbara Seliger
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstr. 1, 04103 Leipzig, Germany
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Downes CEJ, McClure BJ, McDougal DP, Heatley SL, Bruning JB, Thomas D, Yeung DT, White DL. JAK2 Alterations in Acute Lymphoblastic Leukemia: Molecular Insights for Superior Precision Medicine Strategies. Front Cell Dev Biol 2022; 10:942053. [PMID: 35903543 PMCID: PMC9315936 DOI: 10.3389/fcell.2022.942053] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, arising from immature lymphocytes that show uncontrolled proliferation and arrested differentiation. Genomic alterations affecting Janus kinase 2 (JAK2) correlate with some of the poorest outcomes within the Philadelphia-like subtype of ALL. Given the success of kinase inhibitors in the treatment of chronic myeloid leukemia, the discovery of activating JAK2 point mutations and JAK2 fusion genes in ALL, was a breakthrough for potential targeted therapies. However, the molecular mechanisms by which these alterations activate JAK2 and promote downstream signaling is poorly understood. Furthermore, as clinical data regarding the limitations of approved JAK inhibitors in myeloproliferative disorders matures, there is a growing awareness of the need for alternative precision medicine approaches for specific JAK2 lesions. This review focuses on the molecular mechanisms behind ALL-associated JAK2 mutations and JAK2 fusion genes, known and potential causes of JAK-inhibitor resistance, and how JAK2 alterations could be targeted using alternative and novel rationally designed therapies to guide precision medicine approaches for these high-risk subtypes of ALL.
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Affiliation(s)
- Charlotte EJ. Downes
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Barbara J. McClure
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Daniel P. McDougal
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Susan L. Heatley
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
| | - John B. Bruning
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Daniel Thomas
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - David T. Yeung
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Haematology, Royal Adelaide Hospital and SA Pathology, Adelaide, SA, Australia
| | - Deborah L. White
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
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3
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Shi LZ, Bonner JA. Bridging Radiotherapy to Immunotherapy: The IFN-JAK-STAT Axis. Int J Mol Sci 2021; 22:12295. [PMID: 34830176 PMCID: PMC8619591 DOI: 10.3390/ijms222212295] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/10/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022] Open
Abstract
The unprecedented successes of immunotherapies (IOs) including immune checkpoint blockers (ICBs) and adoptive T-cell therapy (ACT) in patients with late-stage cancer provide proof-of-principle evidence that harnessing the immune system, in particular T cells, can be an effective approach to eradicate cancer. This instills strong interests in understanding the immunomodulatory effects of radiotherapy (RT), an area that was actually investigated more than a century ago but had been largely ignored for many decades. With the "newly" discovered immunogenic responses from RT, numerous endeavors have been undertaken to combine RT with IOs, in order to bolster anti-tumor immunity. However, the underlying mechanisms are not well defined, which is a subject of much investigation. We therefore conducted a systematic literature search on the molecular underpinnings of RT-induced immunomodulation and IOs, which identified the IFN-JAK-STAT pathway as a major regulator. Our further analysis of relevant studies revealed that the signaling strength and duration of this pathway in response to RT and IOs may determine eventual immunological outcomes. We propose that strategic targeting of this axis can boost the immunostimulatory effects of RT and radiosensitizing effects of IOs, thereby promoting the efficacy of combination therapy of RT and IOs.
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Affiliation(s)
- Lewis Zhichang Shi
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
- Programs in Immunology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
- O’Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - James A. Bonner
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
- O’Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA
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4
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Morris R, Kershaw NJ, Babon JJ. The molecular details of cytokine signaling via the JAK/STAT pathway. Protein Sci 2019; 27:1984-2009. [PMID: 30267440 DOI: 10.1002/pro.3519] [Citation(s) in RCA: 459] [Impact Index Per Article: 91.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/24/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
More than 50 cytokines signal via the JAK/STAT pathway to orchestrate hematopoiesis, induce inflammation and control the immune response. Cytokines are secreted glycoproteins that act as intercellular messengers, inducing proliferation, differentiation, growth, or apoptosis of their target cells. They act by binding to specific receptors on the surface of target cells and switching on a phosphotyrosine-based intracellular signaling cascade initiated by kinases then propagated and effected by SH2 domain-containing transcription factors. As cytokine signaling is proliferative and often inflammatory, it is tightly regulated in terms of both amplitude and duration. Here we review molecular details of the cytokine-induced signaling cascade and describe the architectures of the proteins involved, including the receptors, kinases, and transcription factors that initiate and propagate signaling and the regulatory proteins that control it.
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Affiliation(s)
- Rhiannon Morris
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
| | - Nadia J Kershaw
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
| | - Jeffrey J Babon
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
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Tanikawa N, Seno K, Kawahara-Miki R, Kimura K, Matsuyama S, Iwata H, Kuwayama T, Shirasuna K. Interferon Tau Regulates Cytokine Production and Cellular Function in Human Trophoblast Cell Line. J Interferon Cytokine Res 2017; 37:456-466. [DOI: 10.1089/jir.2017.0057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Nao Tanikawa
- Laboratory of Animal Reproduction, Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan
| | - Kotomi Seno
- Laboratory of Animal Reproduction, Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan
| | | | - Koji Kimura
- Laboratory of Reproductive Physiology, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Shuichi Matsuyama
- Animal Feeding and Management Research Division, National Institute of Livestock and Grassland Science, Nasushiobara, Japan
| | - Hisataka Iwata
- Laboratory of Animal Reproduction, Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan
| | - Takehito Kuwayama
- Laboratory of Animal Reproduction, Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan
| | - Koumei Shirasuna
- Laboratory of Animal Reproduction, Department of Animal Science, Tokyo University of Agriculture, Atsugi, Japan
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Biswas I, Singh B, Sharma M, Agrawala PK, Khan GA. Extracellular RNA facilitates hypoxia-induced leukocyte adhesion and infiltration in the lung through TLR3-IFN-γ-STAT1 signaling pathway. Eur J Immunol 2015; 45:3158-73. [PMID: 26350442 DOI: 10.1002/eji.201545597] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 08/18/2015] [Accepted: 09/04/2015] [Indexed: 01/12/2023]
Abstract
Endogenous ligands released from dying cells, including extracellular RNA (eRNA), cause TLR activation, which is associated with inflammation and vascular diseases. However, the importance of this response in acute hypoxia (AH) remains unexplored. Here, we observed eRNA-mediated TLR3 activation during exposure of mice to AH in the absence of exogenous viral stimuli. RNaseA treatment diminished AH-induced expression of IFN and cell adhesion molecules (CAMs) and myeloid cell infiltration in the lung, and TLR3 gene silencing or neutralization with antibodies markedly attenuated AH- or poly I:C-induced IFN and CAM expression and leukocyte adhesion (LA) and myeloid cell infiltration in the lung. However, RNaseA treatment or TLR3 gene silencing failed to alter AH-induced cell death and proliferation in lung vasculature. Furthermore, IFN-γ--but not IFN-α--regulated AH-induced CAM expression and LA. Treatment with RNaseA, TLR3 siRNA, neutralizing antibodies, or a STAT1 inhibitor substantially decreased AH- and poly I:C-induced STAT1 phosphorylation, CAM expression, and myeloid cell infiltration, suggesting a central role for STAT1 phosphorylation in AH-induced LA and infiltration. We conclude that eRNA activates TLR3 and facilitates, through in vivo IFN-γ-STAT1 signaling, AH-induced leukocyte infiltration in the lung. Thus, RNaseA might provide a therapeutic alternative for patients with lung diseases.
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Affiliation(s)
- Indranil Biswas
- Department of Physiology, Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India
| | - Bandana Singh
- Department of Physiology, Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India
| | - Manish Sharma
- Department of Proteomics, Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India
| | - Paban K Agrawala
- Institute of Nuclear Medicine and Allied Sciences, Timarpur, Delhi, India
| | - Gausal A Khan
- Department of Physiology, Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India
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7
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JAK2 tyrosine kinase phosphorylates and is negatively regulated by centrosomal protein Ninein. Mol Cell Biol 2014; 35:111-31. [PMID: 25332239 DOI: 10.1128/mcb.01138-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
JAK2 is a cytoplasmic tyrosine kinase critical for cytokine signaling. In this study, we have identified a novel centrosome-associated complex containing ninein and JAK2. We have found that active JAK2 localizes around the mother centrioles, where it partly colocalizes with ninein, a protein involved in microtubule (MT) nucleation and anchoring. We demonstrated that JAK2 is an important regulator of centrosome function. Depletion of JAK2 or use of JAK2-null cells causes defects in MT anchoring and increased numbers of cells with mitotic defects; however, MT nucleation is unaffected. We showed that JAK2 directly phosphorylates the N terminus of ninein while the C terminus of ninein inhibits JAK2 kinase activity in vitro. Overexpressed wild-type (WT) or C-terminal (amino acids 1179 to 1931) ninein inhibits JAK2. This ninein-dependent inhibition of JAK2 significantly decreases prolactin- and interferon gamma (IFN-γ)-induced tyrosyl phosphorylation of STAT1 and STAT5. Downregulation of ninein enhances JAK2 activation. These results indicate that JAK2 is a novel member of centrosome-associated complex and that this localization regulates both centrosomal function and JAK2 kinase activity, thus controlling cytokine-activated molecular pathways.
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8
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Host cell signalling and leishmania mechanisms of evasion. J Trop Med 2011; 2012:819512. [PMID: 22131998 PMCID: PMC3216306 DOI: 10.1155/2012/819512] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 08/16/2011] [Indexed: 12/18/2022] Open
Abstract
Leishmania parasites are able to secure their survival and propagation within their host by altering signalling pathways involved in the ability of macrophages to kill pathogens or to engage adaptive immune system. An important step in this immune evasion process is the activation of host protein tyrosine phosphatase SHP-1 by Leishmania. SHP-1 has been shown to directly inactivate JAK2 and Erk1/2 and to play a role in the negative regulation of several transcription factors involved in macrophage activation. These signalling alterations contribute to the inactivation of critical macrophage functions (e.g., Nitric oxide, IL-12, and TNF-α). Additionally, to interfere with IFN-γ receptor signalling, Leishmania also alters several LPS-mediated responses. Recent findings from our laboratory revealed a pivotal role for SHP-1 in the inhibition of TLR-induced macrophage activation through binding to and inactivating IL-1-receptor-associated kinase 1 (IRAK-1). Furthermore, we identified the binding site as an evolutionarily conserved ITIM-like motif, which we named kinase tyrosine-based inhibitory motif (KTIM). Collectively, a better understanding of the evasion mechanisms utilized by Leishmania parasite could help to develop more efficient antileishmanial therapies in the near future.
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Interferon-γ-induced increases in intestinal epithelial macromolecular permeability requires the Src kinase Fyn. J Transl Med 2011; 91:764-77. [PMID: 21321534 DOI: 10.1038/labinvest.2010.208] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Interferon-γ (IFNγ) is an important immunoregulatory cytokine that can also decrease intestinal epithelial barrier function. Little is known about the intracellular signalling events immediately subsequent to IFNγ/IFNγ receptor interaction that mediate increases in epithelial permeability; data that could be used to ablate this effect of IFNγ while leaving its immunostimulatory effects intact. This study assessed the potential involvement of Src family kinases in IFNγ-induced increases in epithelial permeability using confluent filter-grown monolayers of the human colon-derived T84 epithelial cell line. Inhibition of Src kinase with the pharmacologic PP1 and use of Fyn kinase-specific siRNA significantly reduced IFNγ-induced increases in epithelial permeability as gauged by translocation of noninvasive E. coli (HB101 strain) and flux of horseradish peroxidase (HRP) across monolayers of T84 cells. However, the drop in transepithelial resistance elicited by IFNγ was not affected by either treatment. Immunoblotting revealed that IFNγ activated the transcription factor STAT5 in T84 cells, and immunoprecipitation studies identified an IFNγ-inducible interaction between STAT5b and the PI3K regulatory subunit p85α through formation of a complex requiring the adaptor molecule Gab2. siRNA targeting STAT5b and Gab2 reduced IFNγ-induced increases in epithelial permeability and phosphorylation of PI3K(p85α). PP1 and Fyn siRNA reduced IFNγ-induced PI3K activity (indicated by decreased phospho-Akt) and the formation of the STAT5b/PI3K(p85α) complex. Collectively, the results suggest the formation of a Fyn-dependent STAT5b/Gab2/PI3K complex that links IFNγ to PI3K signalling and the regulation of macromolecular permeability in a model enteric epithelium.
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Kiu H, Greenhalgh CJ, Thaus A, Hilton DJ, Nicola NA, Alexander WS, Roberts AW. Regulation of multiple cytokine signalling pathways by SOCS3 is independent of SOCS2. Growth Factors 2009; 27:384-93. [PMID: 19919527 PMCID: PMC3412171 DOI: 10.3109/08977190903210954] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Suppressor of cytokine signalling (SOCS) 3 is an essential regulator of cytokine signalling, and in turn its expression is tightly regulated. Data from overexpression studies in cell lines suggest that SOCS2 regulates SOCS3 protein degradation, by forming a molecular bridge to an E3 ubiquitin-ligase complex. Whether this regulation is relevant in primary cells is unknown. In this study, we utilized Socs2( - / - ) mice to examine the role of SOCS2 in modulating SOCS3 expression and degradation, and its impact on interleukin-2 (IL-2) and IL-6 signalling in primary haemopoietic cells. Both biochemical and biological analyses demonstrated unperturbed SOCS3 expression and cytokine signalling in the absence of SOCS2. Our results suggest that SOCS2 is not a physiological regulator of SOCS3 expression and action in primary haemopoietic cells.
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Affiliation(s)
- Hiu Kiu
- Division of Cancer and Haematology, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia
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11
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Noncytolytic clearance of sindbis virus infection from neurons by gamma interferon is dependent on Jak/STAT signaling. J Virol 2009; 83:3429-35. [PMID: 19176616 DOI: 10.1128/jvi.02381-08] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The alphavirus Sindbis virus (SINV) causes encephalomyelitis in mice by infecting neurons of the brain and spinal cord. The outcome is age dependent. Young animals develop fatal disease, while older animals recover from infection. Recovery requires noncytolytic clearance of SINV from neurons, and gamma interferon (IFN-gamma) is an important contributor to clearance in vivo. IFN-gamma-dependent clearance has been studied using immortalized CSM14.1 rat neuronal cells that can be differentiated in vitro. Previous studies have shown that differentiated, but not undifferentiated, cells develop prolonged SINV replication and respond to IFN-gamma treatment with noncytolytic clearance of virus preceded by suppression of genomic viral RNA synthesis and reactivation of cellular protein synthesis. To determine the signaling mechanisms responsible for clearance, the responses of SINV-infected differentiated neurons to IFN-gamma were examined. IFN-gamma treatment of SINV-infected differentiated CSM14.1 cells, AP-7 olfactory neuronal cells, and primary dorsal root ganglia neurons triggered prolonged Stat-1 Tyr(701) phosphorylation, Stat-1 Ser(727) phosphorylation, and transient Stat-5 phosphorylation. Inhibition of Jak kinase activity with Jak inhibitor I completely reversed the neuroprotective and antiviral activities of IFN-gamma in differentiated cells. We conclude that activation of the Jak/Stat pathway is the primary mechanism for IFN-gamma-mediated clearance of SINV infection from mature neurons.
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Croker BA, Kiu H, Nicholson SE. SOCS regulation of the JAK/STAT signalling pathway. Semin Cell Dev Biol 2008; 19:414-22. [PMID: 18708154 DOI: 10.1016/j.semcdb.2008.07.010] [Citation(s) in RCA: 456] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 06/18/2008] [Accepted: 07/24/2008] [Indexed: 12/21/2022]
Abstract
The suppressor of cytokine signalling (SOCS) proteins were, as their name suggests, first described as inhibitors of cytokine signalling. While their actions clearly now extend to other intracellular pathways, they remain key negative regulators of cytokine and growth factor signalling. In this review we focus on the mechanics of SOCS action and the complexities of the mouse models that have underpinned our current understanding of SOCS biology.
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Affiliation(s)
- Ben A Croker
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3050 Victoria, Australia
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13
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Siebler J, Protzer U, Wirtz S, Schuchmann M, Höhler T, Galle PR, Neurath MF. Overexpression of STAT-1 by adenoviral gene transfer does not inhibit hepatitis B virus replication. Eur J Gastroenterol Hepatol 2006; 18:167-74. [PMID: 16394798 DOI: 10.1097/00042737-200602000-00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVES Interferons are known to inhibit the replication of hepatitis B viruses (HBV) in several animal models in vitro and in vivo as well in humans. The STAT-1 protein plays a central role in the biological activity of both type I and type II interferons. The lack of functional STAT-1 renders cells and organisms susceptible to bacterial and viral infectious agents. We analysed whether the overexpression of STAT-1 protein enhances the biological interferon response and whether it elicits antiviral activity against HBV in vitro. METHODS To achieve an efficient STAT-1 overexpression in primary liver cells and hepatoma cells, we generated a recombinant, replication-deficient adenovirus expressing human STAT-1 (Adv-STAT-1). We analysed whether the overexpression of STAT-1 inhibits the replication of duck HBV and human HBV in vitro using Western blot analysis, the immunofluorescence of viral proteins and quantification of HBV-DNA copies, respectively. RESULTS In the duck model of HBV infection the overexpression of STAT-1 neither inhibited an established infection nor prevented the establishment of duck HBV replication when administered simultaneously with Adv-STAT-1. These observations were confirmed in an in-vitro model of human HBV infection using the human hepatoma cell line HepG2.2.15, which continuously replicates HBV. CONCLUSION These data demonstrate that the over-expression of STAT-1 alone is not sufficient to strengthen the biological response of interferon as an antiviral agent.
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Affiliation(s)
- Jürgen Siebler
- Labor für Klinische Immunologie I, I. Medizinische Klinik, University of Mainz, Mainz, Germany.
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Ho LJ, Hung LF, Weng CY, Wu WL, Chou P, Lin YL, Chang DM, Tai TY, Lai JH. Dengue virus type 2 antagonizes IFN-alpha but not IFN-gamma antiviral effect via down-regulating Tyk2-STAT signaling in the human dendritic cell. THE JOURNAL OF IMMUNOLOGY 2005; 174:8163-72. [PMID: 15944325 DOI: 10.4049/jimmunol.174.12.8163] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The immunopathogenesis mechanism of dengue virus (DV) infection remains elusive. We previously showed that the target of DV in humans is dendritic cells (DCs), the primary sentinels of immune system. We also observed that despite the significant amount of IFN-alpha induced; DV particles remain massively produced from infected DCs. It suggests that DV may antagonize the antiviral effect of IFN-alpha. Recent work in animal studies demonstrated the differential critical roles of antiviral cytokines, namely IFN-alpha/IFN-beta and IFN-gamma, in blocking early viral production and in preventing viral-mediated disease, respectively. In this study, we examined the effects of IFN-alpha and IFN-gamma in DV infection of monocyte-derived DCs. We showed that the preinfection treatment with either IFN-alpha or IFN-gamma effectively armed DCs and limited viral production in infected cells. However, after infection, DV developed mechanisms to counteract the protection from lately added IFN-alpha, but not IFN-gamma. Such a selective antagonism on antiviral effect of IFN-alpha, but not IFN-gamma, correlated with down-regulated tyrosine-phosphorylation and DNA-binding activities of STAT1 and STAT3 transcription factors by DV. Furthermore, subsequent studies into the underlying mechanisms revealed that DV attenuated IFN-alpha-induced tyrosine-phosphorylation of Tyk2, an upstream molecule of STAT activation, but had no effect on expression of both IFN-alpha receptor 1 and IFN-alpha receptor 2. Moreover, DV infection by itself could activate STAT1 and STAT3 through IFN-alpha-dependent and both IFN-alpha-dependent and IFN-alpha-independent mechanisms, respectively. These observations provide very useful messages with physiological significance in investigation of the pathogenesis, the defense mechanisms of human hosts and the therapeutic considerations in DV infection.
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Affiliation(s)
- Ling-Jun Ho
- Division of Gerontology Research, National Health Research Institute, Academia Sinica, Taipei, Taiwan
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Qing Y, Costa-Pereira AP, Watling D, Stark GR. Role of tyrosine 441 of interferon-gamma receptor subunit 1 in SOCS-1-mediated attenuation of STAT1 activation. J Biol Chem 2005; 280:1849-53. [PMID: 15522878 DOI: 10.1074/jbc.m409863200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Suppressor of cytokine signaling (SOCS)-1, the key negative regulator of interferon (IFN)-gamma-dependent signaling, is induced in response to IFNgamma. SOCS-1 binds to and inhibits the IFNgamma receptor-associated kinase Janus-activated kinase (JAK) 2 and inhibits its function in vitro, but the mechanism by which SOCS-1 inhibits IFNgamma-dependent signaling in vivo is not clear. Upon stimulation, mouse IFNgamma receptor subunit 1 (IFNGR1) is phosphorylated on several cytoplasmic tyrosine residues, and Tyr(419) is required for signal transducer and activator of transcription (STAT) 1 activation in mouse embryo fibroblasts. However, the functions of the other three cytoplasmic tyrosine residues are not known. Here we show that Tyr(441) is required to attenuate STAT1 activation in response to IFNgamma. Several tyrosine to phenylalanine mutants of IFNGR1, expressed at normal levels in stable pools of IFNGR1-null cells, were analyzed for the phosphorylation of STAT1 during a 48-h period, and antiviral activity in response to IFNgamma was also measured. Stronger activation of STAT1 was observed in cells expressing all IFNGR1 variants mutated at Tyr(441), and, consistently, stronger antiviral activity was also observed in these cells. Furthermore, constitutive overexpression of SOCS-1 inhibited IFNgamma-dependent signaling only in cells expressing IFNGR1 variants that included the Tyr(441) mutation. Mutation of Tyr(441) also blocked the ability of SOCS-1 to bind to IFNGR1 and JAK2 in response to IFNgamma and the normal down-regulation of STAT1 activation and antiviral activity. These results, together with data from the literature, suggest a model in which, in response to IFNgamma, phosphorylation of Tyr(441) creates a docking site for SOCS-1, which then binds to JAK2 within the receptor-JAK complex to partially inhibit JAK2 phosphorylation. Furthermore, the virtually complete blockade of STAT1 phosphorylation by overexpressed SOCS-1 in this experiment suggests that the binding of SOCS-1 to Tyr(441) also blocks the access of STAT1 to Tyr(419) and that this effect may be the principal mechanism of inhibition of downstream signaling.
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Affiliation(s)
- Yulan Qing
- Department of Molecular Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Abstract
Interferon-gamma (IFNgamma) is a pluripotent cytokine whose major biological effects are mediated through a pathway in which STAT1 is the predominant and essential transcription factor. STAT3 can also be activated weakly by IFNgamma, but the mechanism of activation and function of STAT3 as a part of the interferon response are not known. Here we show that STAT3 activation is much stronger and more prolonged in STAT1-null mouse embryo fibroblasts than in wild-type cells. In response to IFNgamma, SRC-family kinases are required to activate STAT3 (but not STAT1) through tyrosine phosphorylation, whereas the receptor-bound kinases JAK1 and JAK2 are required to activate both STATs. Tyrosine 419 of the IFNgamma receptor subunit 1 (IFNGR1) is required to activate both STATs, suggesting that STAT1 and STAT3 compete with each other for the same receptor phosphotyrosine motif. Activated STAT3 can replace STAT1 in STAT1-null cells to drive the transcription of certain genes, for example, socs-3 and c/ebpdelta, which have gamma-activated sequence motifs in their promoters. Work from Ian Kerr's laboratory reveals that the gp130-linked interleukin-6 receptor, which usually activates STAT3 predominantly, activates STAT1 efficiently when STAT3 is absent. Because STAT1 and STAT3 have opposing biological effects (STAT3 is an oncogene, and STAT1 is a tumor suppressor), the reciprocal activation of these two transcription factors in response to IFNgamma or interleukin-6 suggests that their relative abundance, which may vary substantially in different normal cell types, under different conditions or in tumors is likely to have a major impact on how cells behave in response to different cytokines.
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Affiliation(s)
- Yulan Qing
- Department of Molecular Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Croker BA, Metcalf D, Robb L, Wei W, Mifsud S, DiRago L, Cluse LA, Sutherland KD, Hartley L, Williams E, Zhang JG, Hilton DJ, Nicola NA, Alexander WS, Roberts AW. SOCS3 is a critical physiological negative regulator of G-CSF signaling and emergency granulopoiesis. Immunity 2004; 20:153-65. [PMID: 14975238 DOI: 10.1016/s1074-7613(04)00022-6] [Citation(s) in RCA: 217] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Revised: 12/18/2003] [Accepted: 12/22/2003] [Indexed: 11/20/2022]
Abstract
To determine the importance of suppressor of cytokine signaling-3 (SOCS3) in the regulation of hematopoietic growth factor signaling generally, and of G-CSF-induced cellular responses specifically, we created mice in which the Socs3 gene was deleted in all hematopoietic cells. Although normal until young adulthood, these mice then developed neutrophilia and a spectrum of inflammatory pathologies. When stimulated with G-CSF in vitro, SOCS3-deficient cells of the neutrophilic granulocyte lineage exhibited prolonged STAT3 activation and enhanced cellular responses to G-CSF, including an increase in cloning frequency, survival, and proliferative capacity. Consistent with the in vitro findings, mutant mice injected with G-CSF displayed enhanced neutrophilia, progenitor cell mobilization, and splenomegaly, but unexpectedly also developed inflammatory neutrophil infiltration into multiple tissues and consequent hind-leg paresis. We conclude that SOCS3 is a key negative regulator of G-CSF signaling in myeloid cells and that this is of particular significance during G-CSF-driven emergency granulopoiesis.
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Affiliation(s)
- Ben A Croker
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research and The Cooperative Research Centre for Cellular Growth Factors, Parkville, Victoria 3050, Australia
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Kortylewski M, Komyod W, Kauffmann ME, Bosserhoff A, Heinrich PC, Behrmann I. Interferon-γ-Mediated Growth Regulation of Melanoma Cells: Involvement of STAT1-Dependent and STAT1-Independent Signals. J Invest Dermatol 2004; 122:414-22. [PMID: 15009724 DOI: 10.1046/j.0022-202x.2004.22237.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Interferon-gamma, a known inhibitor of tumor cell growth, has been used in several protocols for the treatment of melanoma. We have studied the molecular events underlying interferon-gamma-induced G0/G1 arrest in four metastatic melanoma cell lines with different responsiveness to interferon-gamma. The growth arrest did not result from enhanced expression of cyclin-dependent kinase inhibitors p21 and p27. Instead, it correlated with downregulation of cyclin E and cyclin A and inhibition of their associated kinase activities. We show that interferon-gamma-induced growth inhibition could be abrogated by overexpression of dominant negative STAT1 (signal transducer and activator of transcription 1) in the melanoma cell line A375, suggesting that STAT1 plays a crucial part for the anti-proliferative effect. Erythropoietin stimulation of a chimeric receptor led to a concentration-dependent STAT1 activation and concomitant growth arrest when it contained the STAT recruitment motif Y440 of the interferon-gamma receptor 1. In contrast, dose-response studies for interferon-gamma revealed a discrepancy between levels of STAT1 activation and the extent of growth inhibition; whereas STAT1 was activated by low doses of interferon-gamma (10 U per mL), growth inhibitory effects were only visible with 100-fold higher concentrations. Our results suggest the presence of additional signals emanating from the interferon-gamma receptor, which may counteract the anti-proliferative function of STAT1.
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Gatto L, Berlato C, Poli V, Tininini S, Kinjyo I, Yoshimura A, Cassatella MA, Bazzoni F. Analysis of SOCS-3 promoter responses to interferon gamma. J Biol Chem 2004; 279:13746-54. [PMID: 14742442 DOI: 10.1074/jbc.m308999200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SOCS-3 (suppressor of cytokine signaling 3) is an intracellular protein that is selectively and rapidly induced by appropriate agonists and that modulates responses of immune cells to cytokines by interfering with the Janus kinase/signal transducer and activator of transcription (Jak/STAT) pathway. On the basis of the observations that interferon gamma (IFNgamma) up-regulates SOCS-3 gene and protein expression in primary mouse macrophages, J774 macrophage cell line and embryonal fibroblasts, we investigated which sequences of the 5' SOCS-3 gene are responsive to IFNgamma. By promoter deletion analysis we identified a functional IFNgamma-responsive element, located at nucleotides -72/-64 upstream from the transcription initiation, whose presence and integrity is necessary to ensure responsiveness to IFNgamma. This element contains a STAT consensus binding sequence (SOCS-3/STAT-binding element (SBE)) whose specific mutation totally abolished the responsiveness to IFNgamma. In contrast, discrete deletion of other 5' regions of the SOCS-3 promoter did not substantially modify the inducibility by IFNgamma. Electromobility shift assay analyses revealed that IFNgamma promotes specific DNA binding activities to an oligonucleotide probe containing the SOCS-3/SBE sequence. Even though IFNgamma triggered tyrosine phosphorylation of both STAT1 and STAT3 in macrophages and J774 cells, only STAT1 was appropriately activated and thus found to specifically bind to the SOCS-3/SBE oligonucleotide probe. Accordingly, IFNgamma-induced SOCS-3 protein expression was not impaired in STAT3-deficient embryonal fibroblasts. Taken together, these results demonstrate that the induction of SOCS-3 by IFNgamma depends upon the presence of a STAT-binding element in the SOCS-3 promoter that is specifically activated by STAT1.
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Affiliation(s)
- Luana Gatto
- Department of Pathology, University of Verona, Strada le Grazie 4, 37134 Verona, Italy
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Hwa V, Little B, Kofoed EM, Rosenfeld RG. Transcriptional regulation of insulin-like growth factor-I by interferon-gamma requires STAT-5b. J Biol Chem 2003; 279:2728-36. [PMID: 14570891 DOI: 10.1074/jbc.m310495200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-like growth factor (IGF)-I, a growth factor important for cell proliferation, cellular differentiation, and multiple metabolic functions, is regulated in vivo by growth factors and cytokines, but the mechanism(s) of regulation at the cellular level is not well understood. We now demonstrate, employing primary human dermal fibroblasts (CF), that the multipotent cytokine, interferon-gamma (IFN-gamma), can up-regulate IGF-I mRNA expression and that this regulation occurs via activation of the signal transducer and activator of transcription-5b (STAT-5b) pathway. IFN-gamma (100 units/ml) treatment of CF cells resulted in a preferential, time-dependent activation of STAT-5b, although both STAT-5a and STAT-5b isoforms are present. The activated STAT-5b translocated to the nucleus within 30 min of treatment and induced an increase in IGF-I mRNA of 6 +/- 1.0-fold, 3 h post-treatment, with a further increase to 8 +/- 1.7-fold at 5 h. In contrast, IFN-gamma treatment of primary human dermal fibroblasts with a nonfunctional STAT-5b (PF cells) resulted in activation of only STAT-5a and an increase of the IGF-I mRNA level of 1.7 +/- 0.6-fold, 5 h post-treatment. The IFN-gamma-induced regulation of the interferon regulatory factor-1 gene, whose expression is dependent on activated STAT-1, was the same between CF and PF cells. In summary, our results provide evidence of the following in human primary dermal fibroblasts: (a). IFN-gamma preferentially activates STAT-5b, but, in the absence of a functional STAT-5b, STAT-5a is activated; (b). IFN-gamma time-dependently up-regulates IGF-I mRNA expression; (c). the regulation of IGF-I requires an active STAT-5b, and activated STAT-5a cannot substitute for an inactive STAT-5b; and (d). STAT-5b has an essential role in the transcriptional up-regulation of IGF-I.
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Affiliation(s)
- Vivian Hwa
- Department of Pediatrics, Oregon Health and Sciences University, Portland, Oregon 97239-3098, USA.
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Hu X, Li WP, Meng C, Ivashkiv LB. Inhibition of IFN-gamma signaling by glucocorticoids. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:4833-9. [PMID: 12707366 DOI: 10.4049/jimmunol.170.9.4833] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent reports suggest that a novel mechanism of glucocorticoid (GC) immunosuppressive action is inhibition of signaling by IL-2 and IL-12, cytokines that use the Janus kinase-STAT signaling pathway. We investigated whether GCs could also block activation of Janus kinase-STAT signaling by IFN-gamma, a potent proinflammatory cytokine. Addition of dexamethasone to PBMC cultures resulted in a dramatic inhibition of IFN-gamma activation of STAT1. Several days of exposure to GCs were required for inhibition of IFN-gamma signaling to become apparent, and the underlying mechanism was down-regulation of STAT1 expression. GCs suppressed the expression of STAT1 mRNA, but did not affect STAT1 protein stability. STAT1 expression and IFN-gamma signaling were preferentially suppressed in macrophages. GCs did not act directly on macrophages, but worked indirectly by regulating macrophage-lymphocyte interactions that control STAT1 expression. GCs inhibited IFN-gamma-inducible gene expression, thus demonstrating the physiological significance of inhibition of signal transduction. Our results identify a novel level of regulation of IFN-gamma signaling, whereby GCs control the amplitude of IFN-gamma signaling by regulating STAT1 expression. These results suggest that inhibition of IFN-gamma signaling contributes to the immunosuppressive action of GCs.
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Affiliation(s)
- Xiaoyu Hu
- Graduate Program in Immunology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
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Hu X, Herrero C, Li WP, Antoniv TT, Falck-Pedersen E, Koch AE, Woods JM, Haines GK, Ivashkiv LB. Sensitization of IFN-gamma Jak-STAT signaling during macrophage activation. Nat Immunol 2002; 3:859-66. [PMID: 12172544 DOI: 10.1038/ni828] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A general paradigm in signal transduction is ligand-induced feedback inhibition and the desensitization of signaling. We found that subthreshold concentrations of interferon-gamma (IFN-gamma), which did not activate macrophages, increased their sensitivity to subsequent IFN-gamma stimulation; this resulted in increased signal transducer and activator of transcription 1 (STAT1) activation and increased IFN-gamma#150;dependent gene activation. Sensitization of IFN-gamma signaling was mediated by the induction of STAT1 expression by low doses of IFN-gamma that did not effectively induce feedback inhibition. IFN-gamma signaling was sensitized in vivo after IFN-gamma injection, and STAT1 expression was increased after injection of lipopolysaccharide and in rheumatoid arthritis synovial cells. These results identify a mechanism that sensitizes macrophages to low concentrations of IFN-gamma and regulates IFN-gamma responses in acute and chronic inflammation.
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Affiliation(s)
- Xiaoyu Hu
- Graduate Program in Immunology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
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Orlovsky K, Theodor L, Malovani H, Chowers Y, Nir U. Gamma interferon down-regulates Fer and induces its association with inactive Stat3 in colon carcinoma cells. Oncogene 2002; 21:4997-5001. [PMID: 12118379 DOI: 10.1038/sj.onc.1205624] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2002] [Revised: 04/08/2002] [Accepted: 04/26/2002] [Indexed: 11/09/2022]
Abstract
Gamma interferon (IFN-gamma) is a regulator of cell growth, which suppresses the proliferation of HT-29 colon carcinoma cells. Here we show that in HT-29 cells IFN-gamma transiently increased the cellular level of the tyrosine kinase Fer, whose functioning was found to be essential for the proliferation of malignant cell-lines. The transient elevation in the level of Fer, was followed by its down-regulation, an effect which was most prominent after 6-8 h of IFN-gamma treatment. Up- and down-regulation of Fer was paralleled by the activation and subsequent deactivation of Stat3, which is a potent oncogene and a putative substrate of the tyrosine kinase Fer. Moreover, IFN-gamma induced the association of Fer and Stat3 and the newly formed complex was most stable at the down-regulated states of the two proteins. Formation of the Fer/Stat3 complex was accompanied by an attenuation in cell-cycle progression and accumulation of cells in the G1 phase. Thus, Fer and Stat3 are two proliferation-promoting factors whose down-regulation could contribute to the cytostatic activity of IFN-gamma in colon carcinoma cells.
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Affiliation(s)
- Kira Orlovsky
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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Costa-Pereira AP, Tininini S, Strobl B, Alonzi T, Schlaak JF, Is'harc H, Gesualdo I, Newman SJ, Kerr IM, Poli V. Mutational switch of an IL-6 response to an interferon-gamma-like response. Proc Natl Acad Sci U S A 2002; 99:8043-7. [PMID: 12060750 PMCID: PMC123017 DOI: 10.1073/pnas.122236099] [Citation(s) in RCA: 215] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Signaling through Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) is central to the responses to the majority of cytokines and some growth factors, including the interferons (IFNs) and the IL-6 family of cytokines. The biological responses to stimulation through the widely distributed IL-6 and IFN-gamma receptors are, however, completely different. Remarkably, it is shown here that, in mouse embryo fibroblasts lacking STAT3, IL-6 mediates an IFN-gamma-like response including prolonged activation of STAT1, the induction of multiple IFN-gamma-inducible genes, the expression of class II MHC antigens, and an antiviral state. Normal cells exposed to IL-6 thus require a STAT3-dependent function(s) to down-regulate STAT1 activity and prevent an IFN-gamma-like response. The data encourage the view that the very disparate IFN-gamma and IL-6 JAK/receptor complexes mediate a common set of generic or "core" signals which are subject to STAT3-dependent modulation to provide IL-6 specificity. The switching of one cytokine response to one closely mimicking another as a result of the loss of a single signaling component has profound implications, for example, for the interpretation of the phenotypes of knockout mice and for the clinical use of inhibitors of signaling.
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Affiliation(s)
- Ana P Costa-Pereira
- Cancer Research United Kingdom London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom
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