scholarly journals IFN-γ enhances cell-mediated cytotoxicity against keratinocytes via JAK2/STAT1 in lichen planus

2019 ◽  
Vol 11 (511) ◽  
pp. eaav7561 ◽  
Author(s):  
Shuai Shao ◽  
Lam C. Tsoi ◽  
Mrinal K. Sarkar ◽  
Xianying Xing ◽  
Ke Xue ◽  
...  
Keyword(s):  
Lichen Planus ◽  
Therapeutic Agents ◽  
Janus Kinase ◽  
Unknown Etiology ◽  
Type Ii ◽  
Jak Inhibitors ◽  
Coculture Model ◽  
Ifn Γ ◽  
Cytotoxic Responses

Lichen planus (LP) is a chronic debilitating inflammatory disease of unknown etiology affecting the skin, nails, and mucosa with no current FDA-approved treatments. It is histologically characterized by dense infiltration of T cells and epidermal keratinocyte apoptosis. Using global transcriptomic profiling of patient skin samples, we demonstrate that LP is characterized by a type II interferon (IFN) inflammatory response. The type II IFN, IFN-γ, is demonstrated to prime keratinocytes and increase their susceptibility to CD8+ T cell–mediated cytotoxic responses through MHC class I induction in a coculture model. We show that this process is dependent on Janus kinase 2 (JAK2) and signal transducer and activator of transcription 1 (STAT1), but not JAK1 or STAT2 signaling. Last, using drug prediction algorithms, we identify JAK inhibitors as promising therapeutic agents in LP and demonstrate that the JAK1/2 inhibitor baricitinib fully protects keratinocytes against cell-mediated cytotoxic responses in vitro. In summary, this work elucidates the role and mechanisms of IFN-γ in LP pathogenesis and provides evidence for the therapeutic use of JAK inhibitors to limit cell-mediated cytotoxicity in patients with LP.

scholarly journals The Effect of JAK Inhibitor on the Survival, Anagen Re-Entry, and Hair Follicle Immune Privilege Restoration in Human Dermal Papilla Cells

2020 ◽  
Vol 21 (14) ◽  
pp. 5137
Author(s):  
Jung Eun Kim ◽  
Yu Jin Lee ◽  
Hye Ree Park ◽  
Dong Geon Lee ◽  
Kwan Ho Jeong ◽  
...  
Keyword(s):  
Growth Factors ◽  
Hair Follicle ◽  
Dermal Papilla ◽  
Immune Privilege ◽  
Jak Inhibitors ◽  
Dermal Papilla Cells ◽  
Ifn Γ ◽  
Vitro Model ◽  
Stat Pathway

Topical or systemic administration of JAK inhibitors has been shown to be a new treatment modality for severe alopecia areata (AA). Some patients show a good response to JAK inhibitors, but frequently relapse after cessation of the treatment. There have been no guidelines about the indications and use of JAK inhibitors in treating AA. The basic pathomechanism of AA and the relevant role of JAK inhibitors should support how to efficiently use JAK inhibitors. We sought to investigate the effect of JAK1/2 inhibitor on an in vitro model of AA and to examine the possible mechanisms. We used interferon gamma-pretreated human dermal papilla cells (hDPCs) as an in vitro model of AA. Ruxolitinib was administered to the hDPCs, and cell viability was assessed. The change of expression of the Wnt/β-catenin pathway, molecules related to the JAK-STAT pathway, and growth factors in ruxolitinib-treated hDPCs was also examined by reverse transcription PCR and Western blot assay. We examined immune-privilege-related molecules by immunohistochemistry in hair-follicle culture models. Ruxolitinib did not affect the cell viability of the hDPCs. Ruxolitinib activated several molecules in the Wnt/β-catenin signaling pathway, including Lef1 and β-catenin, and suppressed the transcription of DKK1 in hDPCs, but not its translation. Ruxolitinib reverted IFN-γ-induced expression of caspase-1, IL-1β, IL-15, and IL-18, and stimulated several growth factors, such as FGF7. Ruxolitinib suppressed the phosphorylation of JAK1, JAK2 and JAK3, and STAT1 and 3 compared to IFN-γ pretreated hDPCs. Ruxolitinib pretreatment showed a protective effect on IFN-γ-induced expression of MHC-class II molecules in cultured hair follicles. In conclusion, ruxolitinib modulated and reverted the interferon-induced inflammatory changes by blocking the JAK-STAT pathway in hDPCs under an AA-like environment. Ruxolitinib directly stimulated anagen-re-entry signals in hDPCs by affecting the Wnt/β-catenin pathway and promoting growth factors in hDPCs. Ruxolitinib treatment prevented IFN-γ-induced collapse of hair-follicle immune privilege.

scholarly journals P460 Evaluation of potential mechanisms underlying the safety observations of filgotinib in clinical studies in rheumatoid arthritis

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S409-S409
Author(s):  
A Clarke ◽  
J Di Paolo ◽  
B Downie ◽  
A Meng ◽  
N Mollova ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Proliferation ◽  
Clinical Studies ◽  
Nk Cell ◽  
Janus Kinase ◽  
Jak Inhibitor ◽  
Jak Inhibitors ◽  
Erythroid Progenitor ◽  
Cell Counts

Abstract Background Inhibitors of the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway have demonstrated efficacy in the treatment of rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). Differences in selectivity of JAK inhibitors for JAK1, JAK2, JAK3 and TYK2 may influence their respective safety profiles, and the mechanisms responsible are not currently known. Filgotinib (FIL), a JAK1 inhibitor, did not negatively impact haemoglobin, LDL:HDL ratios or natural killer (NK) cell counts in clinical trials. Here, we compare the in vitro mechanistic profiles of four JAK inhibitors at clinically relevant doses. Methods JAK inhibitors (FIL, FIL metabolite [GS-829845], baricitinib [BARI], tofacitinib [TOFA], and upadacitinib [UPA]) were evaluated in vitro in human-cell-based assays. Growth of erythroid progenitors from human cord blood CD34+ cells was assessed using a HemaTox™ liquid expansion assay, NK cell proliferation was induced by IL-15 and LXR agonist-induced cholesteryl ester transfer protein (CETP) expression was assessed in the hepatic cell line, HepG2. Using assay-generated IC50 values and the reported human plasma concentrations from clinical studies, we calculated the target coverage for each JAK inhibitor at clinically relevant doses. The activity of FIL in humans was based on PK/PD modelling of FIL + GS-829845. Results Inhibition of cellular activity was calculated for each JAK inhibitor based on in vitro dose-response data, human exposure data and modelled PK/PD relationships. At clinically relevant doses, FIL resulted in lower calculated inhibition of NK cell proliferation compared with other JAK inhibitors. FIL 100 mg and 200 mg also reduced CETP expression, whereas other JAK inhibitors had no effect. There was no difference in the effect of FIL vs. other JAK inhibitors on erythroid progenitor cell differentiation or maturation. Conclusion FIL, a JAK1 inhibitor, resulted in less inhibition of NK cell proliferation compared with BARI, TOFA, and UPA. FIL also reduced LXR agonist-induced CETP expression, while the other inhibitors did not alter these levels. These results provide a potential mechanistic link between the observed reduction of CETP concentration following FIL treatment and the previously observed reduction in the LDL:HDL ratio in RA patients.

scholarly journals Adjuvant properties of a biocompatible thermo-responsive polymer of N -isopropylacrylamide in autoimmunity and arthritis

2011 ◽  
Vol 8 (65) ◽  
pp. 1748-1759 ◽  
Author(s):  
Akhilesh Kumar Shakya ◽  
Ashok Kumar ◽  
Kutty Selva Nandakumar
Keyword(s):  
Antibody Response ◽  
Collagen Type ◽  
Physical Adsorption ◽  
Type Ii ◽  
Specific Igg ◽  
Ifn Γ ◽  
First Time ◽  
Molecular Weight Form

To evaluate the thermo-responsive poly( N -isopropylacrylamide) (PNiPAAm) polymer as an adjuvant, we synthesized PNiPAAm through free radical polymerization and characterized it both in vitro and in vivo . The polymer when mixed with collagen type II (CII) induced antigen-specific autoimmunity and arthritis. Mice immunized with PNiPAAm–CII developed significant levels of CII-specific IgG response comprising major IgG subclasses. Antigen-specific cellular recall response was also enhanced in these mice, while negligible level of IFN-γ was detected in splenocyte cultures, in vitro . PNiPAAm–CII-immunized arthritic mouse paws showed massive infiltration of immune cells and extensive damage to cartilage and bone. As determined by immunostaining, most of the CII protein retained its native configuration after injecting it with PNiPAAm in naive mice. Physical adsorption of CII and the high-molecular-weight form of moderately hydrophobic PNiPAAm induced a significant anti-CII antibody response. Similar to CII, mice immunized with PNiPAAm and ovalbumin (PNiPAAm–Ova) induced significant anti-ovalbumin antibody response. Comparable levels of serum IFN-γ, IL-1β and IL-17 were observed in ovalbumin-immunized mice with complete Freund, incomplete Freund (CFA and IFA) or PNiPAAm adjuvants. However, serum IL-4 levels were significantly higher in PNiPAAm–Ova and CFA–Ova groups compared with the IFA–Ova group. Thus, we show for the first time, biocompatible and biodegradable thermo-responsive PNiPAAm can be used as an adjuvant in several immunological applications as well as in better understanding of the autoimmune responses against self-proteins.

Jak1 deficiency leads to enhanced Abelson-induced B-cell tumor formation

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4937-4943 ◽  
Author(s):  
Veronika Sexl ◽  
Boris Kovacic ◽  
Roland Piekorz ◽  
Richard Moriggl ◽  
Dagmar Stoiber ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Interferon Γ ◽  
Tumor Formation ◽  
Scid Mice ◽  
Janus Kinase ◽  
Interferon Α ◽  
Ifn Γ ◽  
Transformed Cell Lines

AbstractThe Janus kinase Jak1 has been implicated in tumor formation by the Abelson oncogene. In this study we show that loss of Jak1 does not affect in vitro transformation by v-abl as defined by the ability to induce cytokine-independent B-cell colony formation or establishment of B-cell lines. However, Jak1-deficient, v-abl–transformed cell lines were more tumorgenic than wild-type cells when transplanted subcutaneously into severe combined immunodeficient (SCID) mice or injected intravenously into nude mice. Jak1 deficiency was associated with a loss in the ability of interferon-γ (IFN-γ)to induce growth arrest and/or apoptosis of v-abl–transformed pre-B cells or tumor growth in SCID mice. Moreover, IFN-γ mRNA could be detected in growing tumors, and tumor cells explanted from SCID mice had lost the ability to respond to IFN-γ in 9 of 20 cases, whereas the response to interferon-α (IFN-α) remained intact. Importantly, a similar increase in tumorgenicity was observed when IFN-γ–deficient cells were injected into SCID mice, identifying the tumor cell itself as the main source of IFN-γ. These findings demonstrate that Jak1, rather than promoting tumorgenesis as previously proposed, is critical in mediating an intrinsic IFN-γ–dependent tumor surveillance.

Acute Liver Failure Following Minocycline Treatment – A Case Report and Review of the Literature

2012 ◽  
Vol 50 (08) ◽  
pp. 771-775 ◽  
Author(s):  
A. Kuhn ◽  
C. Weiler-Normann ◽  
C. Schramm ◽  
S. Kluge ◽  
M. Behne ◽  
...  
Keyword(s):  
Liver Failure ◽  
Acute Liver Failure ◽  
Experimental Studies ◽  
Type I ◽  
Type Ii ◽  
Minocycline Treatment ◽  
Tnf Α ◽  
Ige Mediated ◽  
Ifn Γ

AbstractWe present the case of a 23-year-old female patient with acute liver failure following intake of minocycline. This patient had severe hypereosinophilia and massively increased IgE levels. Experimental studies in this case revealed elevated IFN-γ-, as well as TNF-α-producing CD4+ and CD8+ T-cells after in vitro stimulation with minocycline, indicating a type I/IgE-mediated as well as type II/cytotoxic reaction in the pathogenesis of minocycline-induced liver failure. Although mild forms of liver involvement are well known side effects of minocycline, only 8 cases with acute liver failure have been reported, and we present a review of all cases.

scholarly journals A New Cell Enzyme-Linked Immunosorbent Assay Demonstrates Gamma Interferon Suppression by Beta Interferon in Multiple Sclerosis

1999 ◽  
Vol 6 (3) ◽  
pp. 415-419 ◽  
Author(s):  
Moiz Bakhiet ◽  
Volkan Özenci ◽  
Carin Withagen ◽  
Maha Mustafa ◽  
Sten Fredrikson ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Immunosorbent Assay ◽  
Gamma Interferon ◽  
T Cell Response ◽  
Unknown Etiology ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Enzyme ◽  
Ifn Γ

ABSTRACT Multiple sclerosis (MS) is a demyelinating disorder of the central nervous system of unknown etiology. Immune mechanisms involving the proinflammatory cytokine gamma interferon (IFN-γ) are believed to play an important role in the pathogenesis of MS. IFN-β-1b has been introduced as a treatment for MS and was found to reduce the number and severity of clinical exacerbations. To examine the influence of IFN-β-1b on myelin basic protein (MBP)-specific and phytohemagglutinin-induced IFN-γ production, we developed a cell-released capturing enzyme-linked immunosorbent assay (CRC-ELISA), which rapidly measures spontaneous and antigen- or mitogen-induced cellular IFN-γ production. CRC-ELISA documented a significant MBP-specific T-cell response in the blood of untreated MS patients, as assessed by IFN-γ production. This response was suppressed in MS patients treated with IFN-β-1b. The present work confirms in vivo the in vitro suppressive effects of IFN-β-1b on IFN-γ production in MS. Moreover, it provides a powerful new technique for detection of cytokines.

scholarly journals The TATA-containing core promoter of the type II collagen gene (COL2A1) is the target of interferon-gamma-mediated inhibition in human chondrocytes: requirement for Stat1alpha, Jak1 and Jak2

2003 ◽  
Vol 369 (1) ◽  
pp. 103-115 ◽  
Author(s):  
Makoto OSAKI ◽  
Lujian TAN ◽  
Bob K. CHOY ◽  
Yasuhiro YOSHIDA ◽  
Kathryn S.E. CHEAH ◽  
...  
Keyword(s):  
Cell Line ◽  
Core Promoter ◽  
Type Ii Collagen ◽  
Janus Kinase ◽  
Luciferase Reporter ◽  
Regulatory Sequences ◽  
Collagen Gene ◽  
Mrna Levels ◽  
Type Ii ◽  
Ifn Γ

Interferon-γ (IFN-γ) inhibits the synthesis of the cartilage-specific extracellular matrix protein type II collagen, and suppresses the expression of the type II collagen gene (COL2A1) at the transcriptional level. To further examine this mechanism, the responses of COL2A1 regulatory sequences to IFN-γ and the role of components of the Janus kinase/signal transducer and activators of transcription (JAK/STAT) pathway were examined in the immortalized human chondrocyte cell line, C-28/I2. IFN-γ inhibited the mRNA levels of COL2A1 and aggrecan, but not Sox9, L-Sox5 and Sox6, all of which were expressed by these cells as markers of the differentiated phenotype. IFN-γ suppressed the expression of luciferase reporter constructs containing sequences of the COL2A1 promoter spanning −6368 to +125bp in the absence and presence of the intronic enhancer and stimulated activity of the γ-interferon-activated site (GAS) luciferase reporter vector, associated with induction of Stat1α-binding activity in nuclear extracts. These responses to IFN-γ were blocked by overexpression of the JAK inhibitor, JAK-binding protein (JAB), or reversed by dominant-negative Stat1α Y701F containing a mutation at Tyr-701, the JAK phosphorylation site. IFN-γ had no effect on COL2A1 promoter expression in Jak1 (U4A)-, Jak2 (γ2A)- and Stat1α (U3A)-deficient cell lines. In the U3A cell line, the response to IFN-γ was rescued by overexpression of Stat1α, but not by either Stat1α Y701F or Stat1β. Functional analysis using deletion constructs showed that the IFN-γ response was retained in the COL2A1 core promoter region spanning −45 to +11bp, containing the TATA-box and GC-rich sequences but no Stat1-binding elements. Inhibition of COL2A1 promoter activity by IFN-γ persisted in the presence of multiple deletions within the −45/+11bp region. Our results indicate that repression of COL2A1 gene transcription by IFN-γ requires Jak1, Jak2 and Stat1α and suggest that this response involves indirect interaction of activated Stat1α with the general transcriptional machinery that drives constitutive COL2A1 expression.

scholarly journals Epigallocatechin-3 Gallate Inhibits STAT-1/JAK2/IRF-1/HLA-DR/HLA-B and Reduces CD8 MKG2D Lymphocytes of Alopecia Areata Patients

2018 ◽  
Vol 15 (12) ◽  
pp. 2882
Author(s):  
Fatma Hamed ◽  
Andrew McDonagh ◽  
Sarah Almaghrabi ◽  
Youssef Bakri ◽  
Andrew Messenger ◽  
...  
Keyword(s):  
Alopecia Areata ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Active Agent ◽  
Janus Kinase ◽  
Jurkat Cells ◽  
Cd8 Cells ◽  
Hla Dr ◽  
Ifn Γ

Background: Alopecia areata (AA) is associated with Interferon- γ (IFN-γ) mediated T-lymphocyte dysfunction and increased circulating Interleukine-17 (IL-17) levels. Epigallocatechin-3-gallate (EGCG) specifically inhibits IFN-γ pathways and unlike Janus Kinase 1 and 2 (JAK1/JAK2) inhibitors (tofacitinib, ruxolitinib), EGCG is safer, more cost-effective, and is a topically active agent. Our objective is to test the mode of action of EGCG in vitro and ex vivo using HaCat, Jurkat cell lines, and peripheral blood mononuclear cells (PBMCs) of AA patients and healthy controls (HCs), respectively. Methods: distribution of T helper cells (Th1, Th17), and cytotoxic cells (CD8) in PBMCs isolated from 30 AA patients and 30 HCs was investigated by flowcytomterty. In vitro treatment of HaCat and Jurkat cells with 40 μm EGCG for 48 h was performed to measure the level of phosphorylation of signal transducer and activator of transcription protein STAT1, and replicated in ex vivo model using PBMCs of AA patients. Results: Interestingly, 40 μm EGCG is capable of completely inhibiting phosphorylation of STAT1 after 48 h in HaCat and Jurkat cells and ex vivo in PBMCs of AA patients. Based on QPCR data, the action of EGCG on p-STAT1 seems to be mediated via downregulation of the expression of JAK2 but not JAK1 leading to the inhibition of human leukocyte antigens (HLA-DR and HLA-B) expression probably via IRF-1. On the other hand, AA patients have significantly increased levels of Th1, Th17, and CD8 cells and the production of IFN-γ and IL-17 by PBMCs in AA patients was significantly higher compared to HC; p = 0.008 and p = 0.006, respectively. Total numbers of CD8+ cells were not significantly different between treated and untreated samples. However, CD8+ cells with positive Natural killer group 2 member D (NKG2D) transmembrane receptor (CD8+ NKG2D+ subset) was significantly reduced when PBMCs were treated with 20 μm EGCG for 48 h. Conclusion: These results suggest that EGCG has a synergistic action that inhibits expression of HLA-DR and HLA-B molecules via the IFN-γ pathway to maintain immune privilege in HF; also it reduces CD8+ NKG2D+ subset.

scholarly journals Exercise mimetics and JAK inhibition attenuate IFN-γ–induced wasting in engineered human skeletal muscle

2021 ◽  
Vol 7 (4) ◽  
pp. eabd9502 ◽  
Author(s):  
Zhaowei Chen ◽  
Binjie Li ◽  
Ren-Zhi Zhan ◽  
Lingjun Rao ◽  
Nenad Bursac
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Inflammatory Diseases ◽  
Interferon Γ ◽  
Janus Kinase ◽  
Muscle Disease ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Underlying Mechanisms

Chronic inflammatory diseases often lead to muscle wasting and contractile deficit. While exercise can have anti-inflammatory effects, the underlying mechanisms remain unclear. Here, we used an in vitro tissue-engineered model of human skeletal muscle (“myobundle”) to study effects of exercise-mimetic electrical stimulation (E-stim) on interferon-γ (IFN-γ)–induced muscle weakness. Chronic IFN-γ treatment of myobundles derived from multiple donors induced myofiber atrophy and contractile loss. E-stim altered the myobundle secretome, induced myofiber hypertrophy, and attenuated the IFN-γ–induced myobundle wasting and weakness, in part by down-regulating JAK (Janus kinase)/STAT1 (signal transducer and activator of transcription 1) signaling pathway amplified by IFN-γ. JAK/STAT inhibitors fully prevented IFN-γ–induced myopathy, confirming the critical roles of STAT1 activation in proinflammatory action of IFN-γ. Our results reveal a previously unknown mechanism of the cell-autonomous anti-inflammatory effects of muscle exercise and establish the utility of human myobundle platform for studies of inflammatory muscle disease and therapy.

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