Patients with STAT1 gain-of-function (GOF) mutations suffer from an inborn error of immunity hallmarked by chronic mucocutaneous candidiasis (CMC). The pathogenesis behind this complex and heterogeneous disease is still incompletely understood. Beyond the well-recognized Th17 failure, linked to the STAT1/STAT3 dysbalance-driven abrogation of antifungal defense, only little is known about the consequences of augmented STAT1 signaling in other cells, including, interestingly, the innate immune cells. STAT1-mediated signaling was previously shown to be increased in STAT1 GOF CD14+ monocytes. Therefore, we hypothesized that monocytes might represent important co-orchestrators of antifungal defense failure, as well as various immunodysregulatory phenomena seen in patients with STAT1 GOF CMC, including autoimmunity. In this article, we demonstrate that human STAT1 GOF monocytes are characterized by proinflammatory phenotypes and a strong inflammatory skew of their secretory cytokine profile. Moreover, they exhibit diminished CD16 expression, and reduction of classical (CD14++C16-) and expansion of intermediate (CD14++16+) subpopulations. Amongst the functional aberrations, a selectively enhanced responsiveness to TLR7/8 stimulation, but not to other TLR ligands, was noted, which might represent a contributing mechanism in the pathogenesis of STAT1 GOF-associated autoimmunity. Importantly, some of these features extend to STAT1 GOF monocyte-derived dendritic cells and to STAT1 GOF peripheral myeloid dendritic cells, suggesting that the alterations observed in monocytes are, in fact, intrinsic due to STAT1 mutation, and not mere bystanders of chronic inflammatory environment. Lastly, we observe that the proinflammatory bias of STAT1 GOF monocytes may be ameliorated with JAK inhibition. Taken together, we show that monocytes likely play an active role in both the microbial susceptibility and autoimmunity in STAT1 GOF CMC.

• MeSH
• aktivační mutace MeSH
• antifungální látky MeSH
• cytokiny metabolismus   MeSH
• kandidóza chronická mukokutánní * genetika   MeSH
• lidé MeSH
• monocyty metabolismus   MeSH
• toll-like receptor 7 metabolismus   MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

INTRODUCTION: Since the first description of gain of function (GOF) mutations in signal transducer and activator of transcription (STAT) 1, more than 300 patients have been described with a broad clinical phenotype including infections and severe immune dysregulation. Whilst Jak inhibitors (JAKinibs) have demonstrated benefits in several reported cases, their indications, dosing, and monitoring remain to be established. METHODS: A retrospective, multicenter study recruiting pediatric patients with STAT1 GOF under JAKinib treatment was performed and, when applicable, compared with the available reports from the literature. RESULTS: Ten children (median age 8.5 years (3-18), receiving JAKinibs (ruxolitinib (n = 9) and baricitinib (n = 1)) with a median follow-up of 18 months (2-42) from 6 inborn errors of immunity (IEI) reference centers were included. Clinical profile and JAKinib indications in our series were similar to the previously published 14 pediatric patients. 9/10 (our cohort) and 14/14 patients (previous reports) showed partial or complete responses. The median immune deficiency and dysregulation activity scores were 15.99 (5.2-40) pre and 7.55 (3-14.1) under therapy (p = 0.0078). Infection, considered a likely adverse event of JAKinib therapy, was observed in 1/10 patients; JAKinibs were stopped in 3/10 children, due to hepatotoxicity, pre-HSCT, and absence of response. CONCLUSIONS: Our study supports the potentially beneficial use of JAKinibs in patients with STAT1 GOF, in line with previously published data. However, consensus regarding their indications and timing, dosing, treatment duration, and monitoring, as well as defining biomarkers to monitor clinical and immunological responses, remains to be determined, in form of international prospective multicenter studies using established IEI registries.

• MeSH
• aktivační mutace * MeSH
• dítě MeSH
• inhibitory Janus kinas * terapeutické užití   MeSH
• lidé MeSH
• multicentrické studie jako téma MeSH
• retrospektivní studie MeSH
• transkripční faktor STAT1 * genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Pegylated interferon-α (peg-IFNa) treatment induces molecular responses (MR) in patients with myeloproliferative neoplasms (MPNs), including partial MR (PMR) in 30-40% of patients. Here, we compared the efficacy of IFNa treatment in JAK2V617F- vs. calreticulin (CALR)-mutated cells and investigated the mechanisms of differential response. Retrospective analysis of MPN patients treated with peg-IFNa demonstrated that patients harboring the JAK2V617F mutation were more likely to achieve PMR than those with mutated CALR (p = 0.004), while there was no significant difference in hematological response. In vitro experiments confirmed an upregulation of IFN-stimulated genes in JAK2V617F-positive 32D cells as well as patient samples (peripheral blood mononuclear cells and CD34+ hematopoietic stem cells) compared to their CALR-mutated counterparts, and higher IFNa doses were needed to achieve the same IFNa response in CALR- as in JAK2V617F-mutant 32D cells. Additionally, Janus-activated kinase-1 (JAK1) and signal transducers and activators of transcription 1 (STAT1) showed constitutive phosphorylation in JAK2V617F-mutated but not CALR-mutated cells, indicating priming towards an IFNa response. Moreover, IFN-induced growth arrest was counteracted by selective JAK1 inhibition but enhanced by JAK2 inhibition. In conclusion, our data suggest that, clinically, higher doses of IFNa are needed in CALR-mutated vs. JAK2V617F-positive patients and we suggest a model of JAK2V617F-JAK1/STAT1 crosstalk leading to a priming of JAK2V617F-positive cells to IFNa resulting in differential sensitivity.

• MeSH
• antivirové látky farmakologie   MeSH
• apoptóza MeSH
• dospělí MeSH
• interferon alfa farmakologie   MeSH
• Janus kinasa 1 genetika   metabolismus   MeSH
• Janus kinasa 2 genetika   MeSH
• kalretikulin genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace * MeSH
• myeloproliferativní poruchy farmakoterapie   genetika   metabolismus   patologie   MeSH
• myši MeSH
• nádorové biomarkery genetika   metabolismus   MeSH
• nádorové buňky kultivované MeSH
• následné studie MeSH
• prognóza MeSH
• proliferace buněk MeSH
• retrospektivní studie MeSH
• senioři MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

It has been suggested that tick saliva facilitates transmission of tick-borne encephalitis virus (TBEV) to vertebrates. The mechanism of this facilitation has not been elucidated yet. Since dendritic cells (DCs) are among first cells attacked by the virus, we examined the amount of virus and changes induced by saliva in TBEV-infected DCs. We found that virus replication was significantly increased by saliva of Ixodes ricinus tick. Next, saliva-induced enhancement of Akt pathway activation was observed in TBEV-infected DCs. Akt mediated pathway is known for its anti-apoptotic and pro-survival effects. Accordingly, apoptosis of TBEV-infected DCs was declined and cellular viability increased in the presence of tick saliva. Saliva-induced enhancement of STAT1 and NF-κB was also observed in TBEV-infected DCs. In conclusion, we suggest that tick saliva provides pro-survival and anti-apoptotic signals to infected DCs via upregulation of Akt, which may have positive consequences for TBEV replication and transmission.

• MeSH
• apoptóza MeSH
• arachnida jako vektory virologie   MeSH
• dendritické buňky cytologie   metabolismus   virologie   MeSH
• klíště virologie   MeSH
• klíšťová encefalitida metabolismus   patofyziologie   přenos   virologie   MeSH
• lidé MeSH
• morčata MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• protoonkogenní proteiny c-akt genetika   metabolismus   MeSH
• replikace viru MeSH
• sliny virologie   MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• viry klíšťové encefalitidy genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• morčata MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• autoimunita * genetika   MeSH
• cílená molekulární terapie MeSH
• guanylátcyklasa genetika   MeSH
• lidé MeSH
• mutace genetika   MeSH
• signální adaptorové proteiny CARD genetika   MeSH
• signální transdukce MeSH
• syndromy imunologické nedostatečnosti * genetika   imunologie   MeSH
• transkripční faktor STAT1 genetika   MeSH
• transkripční faktor STAT3 genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

PURPOSE: Signal transducer and activator of transcription 1 gain-of-function (STAT1 GOF) mutations are the most common cause of chronic mucocutaneous candidiasis (CMC). We aim to report the effect of oral ruxolitinib, the Janus kinase (JAK) family tyrosine kinase inhibitor, on clinical and immune status of a 12-year-old boy with severe CMC due to a novel STAT1 GOF mutation. METHODS: Clinical features and laboratory data were analyzed, particularly lymphocyte subsets, ex vivo IFNγ- and IFNα-induced STAT1, 3, 5 phosphorylation dynamics during the course of JAK1/2 inhibition therapy, and Th17-related, STAT1- and STAT3-inducible gene expression before and during the treatment. Sanger sequencing was used to detect the STAT1 mutation. Literature review of ruxolitinib in treatment of CMC is appended. RESULTS: A novel STAT1 GOF mutation (c.617T > C; p.L206P), detected in a child with recalcitrant CMC, was shown to be reversible in vitro with ruxolitinib. Major clinical improvement was achieved after 8 weeks of ruxolitinib treatment, while sustained suppression of IFNγ- and IFNα-induced phosphorylation of STAT1, STAT3, and STAT5, as well as increased STAT3-inducible and Th17-related gene expression, was demonstrated ex vivo. Clinical relapse and spike of all monitored phosphorylated STAT activity was registered shortly after unplanned withdrawal, decreasing again after ruxolitinib reintroduction. No increase of peripheral CD4+ IL17+ T cells was detected after 4 months of therapy. No adverse effects were noted. CONCLUSION: JAK1/2 inhibition with ruxolitinib represents a viable option for treatment of refractory CMC, if HSCT is not considered. However, long-term administration is necessary, as the effect is not sustained after treatment discontinuation.

• MeSH
• aktivační mutace * MeSH
• biologické markery MeSH
• CD4-pozitivní T-lymfocyty imunologie   metabolismus   MeSH
• cytokiny metabolismus   MeSH
• dítě MeSH
• fosforylace MeSH
• genetická predispozice k nemoci MeSH
• imunofenotypizace MeSH
• inhibitory proteinkinas aplikace a dávkování   terapeutické užití   MeSH
• Janus kinasy antagonisté a inhibitory   MeSH
• kandidóza chronická mukokutánní diagnóza   farmakoterapie   genetika   metabolismus   MeSH
• lidé MeSH
• mutace * MeSH
• mutační analýza DNA MeSH
• pyrazoly aplikace a dávkování   terapeutické užití   MeSH
• T-lymfocyty - podskupiny imunologie   metabolismus   MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

Vrozená vnímavost k mykobakteriálním onemocněním (Mendelian Susceptibility to Mycobacterial Diseases) je skupina monogenně podmíněných primárních imunodeficitů způsobených defekty v jednotlivých komponentech signalizační kaskády IL12-IL23/IFNγ zajišťující komunikaci mezi fagocyty a Th1 lymfocyty. Onemocnění se projevují selektivně sníženou obranyschopností proti mykobakteriím (především proti oportunně patogenním kmenům) a netyfoidním salmonelám, přičemž ostatní antimikrobiální imunita zůstává intaktní. Závažnost onemocnění se pohybuje od lokálních komplikací v místě inokulace BCG vakcíny až po fatální diseminované infekce. Předkládané kazuistiky popisují první dva pacienty diagnostikované v ČR: děvče s mutací receptoru pro IFNγ a chlapce s loss of function STAT1 mutací.

Mendelian Susceptibility to Mycobacterial Diseases (MSMD) encompasses a newly emerged group of monogenic primary immunodeficiencies caused by defects in IL12-IL23/IFNγ mediated mononuclear phagocyte-Th1 communication pathway. Patients typically display various degree of selective impairment of immunity against mycobacteria (particularly against weakly virulent strains) and nontyphoid salmonellae; other aspects of host defence remain intact. Depending on the specific mutation, the clinical presentation ranges from mild adverse reactions to BCG vaccine to life-threatening disseminated mycobacterial infections and salmonellosis. The following case review reports on first two patients diagnosed with MSMD in the Czech Republic: a girl with IFNγ receptor mutation and a boy with STAT1 loss of function mutation.

• Klíčová slova
• MSMD,
• MeSH
• antibakteriální látky terapeutické užití   MeSH
• antituberkulotika terapeutické užití   MeSH
• BCG vakcína genetika   škodlivé účinky   MeSH
• dítě MeSH
• genetická predispozice k nemoci * MeSH
• genetické testování MeSH
• imunologické testy MeSH
• interferon gama MeSH
• interleukin-12 MeSH
• klinické laboratorní techniky MeSH
• kojenec MeSH
• lidé MeSH
• mutace MeSH
• mykobakteriózy * diagnóza   farmakoterapie   genetika   MeSH
• transkripční faktor STAT1 genetika   imunologie   MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH

In 1994, the field of bone biology was significantly advanced by the discovery that activating mutations in the fibroblast growth factor receptor 3 (FGFR3) receptor tyrosine kinase (TK) account for the common genetic form of dwarfism in humans, achondroplasia (ACH). Other conditions soon followed, with the list of human disorders caused by FGFR3 mutations now reaching at least 10. An array of vastly different diagnoses is caused by similar mutations in FGFR3, including syndromes affecting skeletal development (hypochondroplasia [HCH], ACH, thanatophoric dysplasia [TD]), skin (epidermal nevi, seborrhaeic keratosis, acanthosis nigricans), and cancer (multiple myeloma [MM], prostate and bladder carcinoma, seminoma). Despite many years of research, several aspects of FGFR3 function in disease remain obscure or controversial. As FGFR3-related skeletal dysplasias are caused by growth attenuation of the cartilage, chondrocytes appear to be unique in their response to FGFR3 activation. However, the reasons why FGFR3 inhibits chondrocyte growth while causing excessive cellular proliferation in cancer are not clear. Likewise, the full spectrum of molecular events by which FGFR3 mediates its signaling is just beginning to emerge. This article describes the challenging journey to unravel the mechanisms of FGFR3 function in skeletal dysplasias, the extraordinary cellular manifestations of FGFR3 signaling in chondrocytes, and finally, the progress toward therapy for ACH and cancer.

• MeSH
• chondrocyty metabolismus   patologie   MeSH
• chrupavka abnormality   metabolismus   MeSH
• fibroblastové růstové faktory genetika   metabolismus   MeSH
• fosfatidylinositol-3-kinasy genetika   metabolismus   MeSH
• kosti a kostní tkáň abnormality   metabolismus   MeSH
• kůže metabolismus   patologie   MeSH
• letální geny MeSH
• lidé MeSH
• MAP kinasový signální systém genetika   MeSH
• mezibuněčná komunikace MeSH
• mutace MeSH
• nádory kůže genetika   metabolismus   patologie   MeSH
• natriuretický peptid typu C genetika   metabolismus   MeSH
• osteochondrodysplazie genetika   metabolismus   patologie   MeSH
• proliferace buněk MeSH
• receptor fibroblastových růstových faktorů, typ 3 genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• signální transdukce MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH

Cellular senescence guards against cancer and modulates aging; however, the underlying mechanisms remain poorly understood. Here, we show that genotoxic drugs capable of inducing premature senescence in normal and cancer cells, such as 5-bromo-2'-deoxyuridine (BrdU), distamycin A (DMA), aphidicolin and hydroxyurea, persistently activate Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling and expression of interferon-stimulated genes (ISGs), such as MX1, OAS, ISG15, STAT1, PML, IRF1 and IRF7, in several human cancer cell lines. JAK1/STAT-activating ligands, interleukin 10 (IL10), IL20, IL24, interferon gamma (IFNgamma), IFNbeta and IL6, were also expressed by senescent cells, supporting autocrine/paracrine activation of JAK1/STAT. Furthermore, cytokine genes, including proinflammatory IL1, tumor necrosis factor and transforming growth factor families, were highly expressed. The strongest inducer of JAK/STAT signaling, cytokine production and senescence was BrdU combined with DMA. RNA interference-mediated knockdown of JAK1 abolished expression of ISGs, but not DNA damage signaling or senescence. Thus, although DNA damage signaling, p53 and RB activation, and the cytokine/chemokine secretory phenotype are apparently shared by all types of senescence, our data reveal so far unprecedented activation of the IFNbeta-STAT1-ISGs axis, and indicate a less prominent causative role of IL6-JAK/STAT signaling in genotoxic drug-induced senescence compared with reports on oncogene-induced or replicative senescence. These results highlight shared and unique features of drug-induced cellular senescence, and implicate induction of cancer secretory phenotype in chemotherapy.

• MeSH
• bromodeoxyuridin farmakologie   MeSH
• cytokiny genetika   metabolismus   MeSH
• distamyciny farmakologie   MeSH
• HeLa buňky MeSH
• interferony genetika   metabolismus   MeSH
• interleukin-10 genetika   metabolismus   MeSH
• interleukin-6 genetika   metabolismus   MeSH
• interleukin-8 genetika   metabolismus   MeSH
• interleukiny genetika   metabolismus   MeSH
• Janus kinasa 1 genetika   metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• stárnutí buněk účinky léků   MeSH
• synergismus léků MeSH
• transkripční faktor STAT1 genetika   metabolismus   MeSH
• western blotting MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

Activating mutations in fibroblast growth factor receptor 3 (FGFR3) cause several human skeletal dysplasias as a result of attenuation of cartilage growth. It is believed that FGFR3 inhibits chondrocyte proliferation via activation of signal transducers and activators of transcription (STAT) proteins, although the exact mechanism of both STAT activation and STAT-mediated inhibition of chondrocyte growth is unclear. We show that FGFR3 interacts with STAT1 in cells and is capable of activating phosphorylation of STAT1 in a kinase assay, thus potentially serving as a STAT1 kinase in chondrocytes. However, as demonstrated by western blotting with phosphorylation-specific antibodies, imaging of STAT nuclear translocation, STAT transcription factor assays and STAT luciferase reporter assays, FGF does not activate STAT1 or STAT3 in RCS chondrocytes, which nevertheless respond to a FGF stimulus with potent growth arrest. Moreover, addition of active STAT1 and STAT3 to the FGF signal, by means of cytokine treatment, SRC-mediated STAT activation or expression of constitutively active STAT mutants does not sensitize RCS chondrocytes to FGF-mediated growth arrest. Since FGF-mediated growth arrest is rescued by siRNA-mediated downregulation of the MAP kinase ERK1/2 but not STAT1 or STAT3, our data support a model whereby the ERK arm but not STAT arm of FGF signaling in chondrocytes accounts for the growth arrest phenotype.

• MeSH
• buněčné linie MeSH
• chondrocyty cytologie   metabolismus   účinky léků   MeSH
• fibroblastové růstové faktory farmakologie   metabolismus   MeSH
• fibroblastový růstový faktor 2 farmakologie   metabolismus   MeSH
• financování organizované MeSH
• fosforylace MeSH
• interferon gama farmakologie   MeSH
• interleukin-6 farmakologie   MeSH
• lidé MeSH
• luminescentní proteiny genetika   metabolismus   MeSH
• malá interferující RNA genetika   MeSH
• mutageneze cílená MeSH
• proliferace buněk účinky léků   MeSH
• receptor fibroblastových růstových faktorů, typ 3 genetika   metabolismus   MeSH
• rekombinantní fúzní proteiny genetika   metabolismus   MeSH
• RNA interference MeSH
• sekvence nukleotidů MeSH
• signální transdukce MeSH
• transfekce MeSH
• transkripční faktor STAT1 antagonisté a inhibitory   genetika   metabolismus   MeSH
• transkripční faktor STAT3 antagonisté a inhibitory   genetika   metabolismus   MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH