STAT1 gain-of-function (GOF) mutations cause an inborn error of immunity with diverse phenotype ranging from chronic mucocutaneous candidiasis (CMC) to various non-infectious manifestations, the most precarious of which are autoimmunity and vascular complications. The pathogenesis centers around Th17 failure but is far from being understood. We hypothesized that neutrophils, whose functions have not been explored in the context of STAT1 GOF CMC yet, might be involved in the associated immunodysregulatory and vascular pathology. In a cohort of ten patients, we demonstrate that STAT1 GOF human ex-vivo peripheral blood neutrophils are immature and highly activated; have strong propensity for degranulation, NETosis, and platelet-neutrophil aggregation; and display marked inflammatory bias. STAT1 GOF neutrophils exhibit increased basal STAT1 phosphorylation and expression of IFN stimulated genes, but contrary to other immune cells, STAT1 GOF neutrophils do not display hyperphosphorylation of STAT1 molecule upon stimulation with IFNs. The patient treatment with JAKinib ruxolitinib does not ameliorate the observed neutrophil aberrations. To our knowledge, this is the first work describing features of peripheral neutrophils in STAT1 GOF CMC. The presented data suggest that neutrophils may contribute to the immune pathophysiology of the STAT1 GOF CMC.

• MeSH
• aktivační mutace * MeSH
• autoimunita MeSH
• fenotyp MeSH
• fosforylace MeSH
• kandidóza chronická mukokutánní * farmakoterapie   genetika   MeSH
• lidé MeSH
• neutrofily metabolismus   MeSH
• transkripční faktor STAT1 * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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

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

Inflammatory and oncogenic signaling converge in disease evolution of BCR-ABL-negative myeloproliferative neoplasms, clonal hematopoietic stem cell disorders characterized by gain-of-function mutation in JAK2 kinase (JAK2V617F), with highest prevalence in patients with polycythemia vera (PV). Despite the high risk, DNA-damaging inflammatory microenvironment, PV progenitors tend to preserve their genomic stability over decades until their progression to post-PV myelofibrosis/acute myeloid leukemia. Using induced pluripotent stem cells-derived CD34+ progenitor-enriched cultures from JAK2V617F+ PV patient and from JAK2 wild-type healthy control, CRISPR-modified HEL cells and patients' bone marrow sections from different disease stages, we demonstrate that JAK2V617F induces an intrinsic IFNγ- and NF-κB-associated inflammatory program, while suppressing inflammation-evoked DNA damage both in vitro and in vivo. We show that cells with JAK2V617F tightly regulate levels of inflammatory cytokines-induced reactive oxygen species, do not fully activate the ATM/p53/p21waf1 checkpoint and p38/JNK MAPK stress pathway signaling when exposed to inflammatory cytokines, suppress DNA single-strand break repair genes' expression yet overexpress the dual-specificity phosphatase (DUSP) 1. RNAi-mediated knock-down and pharmacological inhibition of DUSP1, involved in p38/JNK deactivation, in HEL cells reveals growth addiction to DUSP1, consistent with enhanced DNA damage response and apoptosis in DUSP1-inhibited parental JAK2V617F+ cells, but not in CRISPR-modified JAK2 wild-type cells. Our results indicate that the JAK2V617F+ PV progenitors utilize DUSP1 activity as a protection mechanism against DNA damage accumulation, promoting their proliferation and survival in the inflammatory microenvironment, identifying DUSP1 as a potential therapeutic target in PV.

• MeSH
• cytokiny genetika   metabolismus   MeSH
• fosfatasa 1 s dvojí specificitou genetika   MeSH
• hematopoetické kmenové buňky patologie   MeSH
• indukované pluripotentní kmenové buňky patologie   MeSH
• Janus kinasa 2 genetika   MeSH
• lidé MeSH
• mutace MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí MeSH
• oxidační stres * MeSH
• polycythaemia vera genetika   MeSH
• poškození DNA * MeSH
• proliferace buněk * MeSH
• reprodukovatelnost výsledků MeSH
• transkripční faktor STAT1 metabolismus   MeSH
• zánět metabolismus   MeSH
• Check Tag
• lidé 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

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

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

The resistance to interferons (IFNs) limits their anticancer therapeutic efficacy. Here we studied the antiproliferative effect of interferon gamma in relation to SOCS3 expression in a panel of breast cancer cell lines and normal mammary epithelial cells. Compared to normal cells most breast cancer lines (7/8) were highly resistant to IFN-gamma. Using Northern blot and real time RT-PCR we investigated transcription of SOCS3 genes. All normal epithelial cells (4/4) showed SOCS3 induction (2-14 fold) while most breast cancer lines did not or weakly activated SOCS3 after the interferon gamma treatment. Among the cancer lines, the MDA-MB-468 cells showed increased sensitivity to IFN-gamma and relatively high level of SOCS3 induction (2-3 fold). Together, there was a good correlation

• MeSH
• chemorezistence MeSH
• fosforylace MeSH
• interferon gama farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory prsu farmakoterapie   metabolismus   patologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteiny SOCS genetika   MeSH
• prsy metabolismus   účinky léků   MeSH
• transkripční faktor STAT1 metabolismus   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Activation of fibroblast growth factor receptor 3 (FGFR3) leads to attenuation of cartilage growth. The members of the STAT family of transcription factors are believed to participate in FGFR3 signaling in cartilage, however the molecular mechanism of this action is poorly understood. Here, we demonstrate that a chronic FGF stimulus leads to accumulation of STAT1, 3, 5 and 6, evident in both in vitro chondrocyte model and murine limb explant cultures. Despite the accumulation, both endogenous and cytokine-induced activation of STAT1 and STAT3 is impaired by FGF, as demonstrated by imaging of active STAT nuclear translocation and analyses of STAT activatory phosphorylation and transcriptional activation. Further, we demonstrate that FGF induces expression of CIS, SOCS1 and SOCS3 inhibitors of gp130, a common receptor for the IL6-family of cytokines. Since cytokine-gp130 signaling represents an important positive regulator of cartilage, its inhibition may contribute to the growth-inhibitory effect of FGFR3 in cartilage.

• MeSH
• chondrocyty metabolismus   účinky léků   MeSH
• cytokinový receptor gp130 metabolismus   MeSH
• fibroblastový růstový faktor 2 farmakologie   MeSH
• financování organizované MeSH
• interferon gama antagonisté a inhibitory   farmakologie   MeSH
• interleukin-6 antagonisté a inhibitory   farmakologie   MeSH
• myši MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteiny SOCS metabolismus   MeSH
• receptor fibroblastových růstových faktorů, typ 3 metabolismus   MeSH
• sekvence nukleotidů MeSH
• signální transdukce MeSH
• transkripční faktor STAT1 antagonisté a inhibitory   metabolismus   MeSH
• transkripční faktor STAT3 antagonisté a inhibitory   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH