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.

• Klíčová slova
• Neutrophils, STAT1 GOF, autoimmunity, candidiasis, platelets, ruxolitinib,
• 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
• Názvy látek
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 * MeSH

STAT1 gain-of-function (GOF) mutations underlie an inborn error of immunity hallmarked by chronic mucocutaneous candidiasis (CMC). Beyond the fungal susceptibility, attributed to Th17 failure, over half of the reported patients suffer from autoimmune manifestations, mechanism of which has not been explained yet. We hypothesized that the STAT1 mutations would affect dendritic cells' (DCs) properties and alter their inflammatory and tolerogenic functions. To test the hypothesis, we generated monocyte-derived DCs (moDCs) and tolerogenic DCs (tDCs). Functional and signaling studies, co-culture experiments and RNA sequencing demonstrated that STAT1 GOF DCs were profoundly altered in their phenotype and functions, characterized by loss of tolerogenic functions, proinflammatory skew and decreased capacity to induce Th17. Cytokine signaling, autophagy and metabolic processes were identified as the most prominently altered cellular processes. The results suggest that DCs are directly involved in STAT1 GOF-associated immune pathology, possibly contributing to both autoimmune manifestations and the failure of antifungal defense.

• Klíčová slova
• Autophagy, CMC, Candidiasis, Dendritic cells, Ruxolitinib, STAT1, Tolerogenic,
• MeSH
• aktivační mutace * MeSH
• autoimunita genetika   MeSH
• dendritické buňky metabolismus   MeSH
• kandidóza chronická mukokutánní * genetika   MeSH
• lidé MeSH
• mutace MeSH
• transkripční faktor STAT1 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 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.

• Klíčová slova
• STAT1, candidiasis, cmc, dendritic cell, immunodeficiencies, monocytes, ruxolitinib,
• 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
• Názvy látek
• antifungální látky MeSH
• cytokiny MeSH
• STAT1 protein, human MeSH Prohlížeč
• toll-like receptor 7 MeSH
• transkripční faktor STAT1 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.

• Klíčová slova
• Baricitinib, Children, Chronic mucocutaneous candidiasis, Inborn errors of immunity, JAK inhibitors, JAK-STAT pathway, Pediatrics, Primary immunodeficiency disease, Ruxolitinib, STAT1 GOF,
• 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
• Názvy látek
• inhibitory Janus kinas * MeSH
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 * MeSH

• MeSH
• aktivační mutace imunologie   MeSH
• COVID-19 imunologie   MeSH
• imunogenicita vakcíny imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mRNA vakcíny škodlivé účinky   imunologie   MeSH
• protilátky virové imunologie   MeSH
• SARS-CoV-2 imunologie   MeSH
• syntetické vakcíny škodlivé účinky   imunologie   MeSH
• transkripční faktor STAT1 imunologie   MeSH
• vakcíny proti COVID-19 škodlivé účinky   imunologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mRNA vakcíny MeSH
• protilátky virové MeSH
• STAT1 protein, human MeSH Prohlížeč
• syntetické vakcíny MeSH
• transkripční faktor STAT1 MeSH
• vakcíny proti COVID-19 MeSH

Interferon (IFN)-related DNA damage resistant signature (IRDS) genes are a subgroup of interferon-stimulated genes (ISGs) found upregulated in different cancer types, which promotes resistance to DNA damaging chemotherapy and radiotherapy. Along with briefly discussing IFNs and signalling in this review, we highlighted how different IRDS genes are affected by viruses. On the contrary, different strategies adopted to suppress a set of IRDS genes (STAT1, IRF7, OAS family, and BST2) to induce (chemo- and radiotherapy) sensitivity were deliberated. Significant biological pathways that comprise these genes were classified, along with their frequently associated genes (IFIT1/3, IFITM1, IRF7, ISG15, MX1/2 and OAS1/3/L). Major upstream regulators from the IRDS genes were identified, and different IFN types regulating these genes were outlined. Functional interfaces of IRDS proteins with DNA/RNA/ATP/GTP/NADP biomolecules featured a well-defined pharmacophore model for STAT1/IRF7-dsDNA and OAS1/OAS3/IFIH1-dsRNA complexes, as well as for the genes binding to GDP or NADP+. The Lys amino acid was found commonly interacting with the ATP phosphate group from OAS1/EIF2AK2/IFIH1 genes. Considering the premise that targeting IRDS genes mediated resistance offers an efficient strategy to resensitize tumour cells and enhances the outcome of anti-cancer treatment, this review can add some novel insights to the field.

• Klíčová slova
• ATP, DNA, DNA damage, IRDS genes, RNA, chemotherapy and radiotherapy, functional site, interferon, protein interfaces, receptors, resistance, upstream regulator, viruses,
• MeSH
• adaptorové proteiny signální transdukční fyziologie   MeSH
• aktivace transkripce MeSH
• chemorezistence genetika   fyziologie   MeSH
• dvouvláknová RNA MeSH
• interferonový regulační faktor 7 MeSH
• interferony metabolismus   fyziologie   MeSH
• intracelulární signální peptidy a proteiny MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• poškození DNA genetika   fyziologie   MeSH
• proteiny vázající RNA MeSH
• signální transdukce MeSH
• transkripční faktor STAT1 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• dvouvláknová RNA MeSH
• IFIT1 protein, human MeSH Prohlížeč
• IFIT3 protein, human MeSH Prohlížeč
• interferonový regulační faktor 7 MeSH
• interferony MeSH
• intracelulární signální peptidy a proteiny MeSH
• IRF7 protein, human MeSH Prohlížeč
• proteiny vázající RNA MeSH
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 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
• Názvy látek
• cytokiny MeSH
• DUSP1 protein, human MeSH Prohlížeč
• fosfatasa 1 s dvojí specificitou MeSH
• JAK2 protein, human MeSH Prohlížeč
• Janus kinasa 2 MeSH
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 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
• Názvy látek
• antivirové látky MeSH
• CALR protein, human MeSH Prohlížeč
• interferon alfa MeSH
• JAK1 protein, human MeSH Prohlížeč
• JAK2 protein, human MeSH Prohlížeč
• Janus kinasa 1 MeSH
• Janus kinasa 2 MeSH
• kalretikulin MeSH
• nádorové biomarkery MeSH
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 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.

• Klíčová slova
• Chronic mucocutaneous candidiasis, Janus kinase inhibitor, candida, ruxolitinib, signal transducer and activator of transcription 1,
• 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
• nitrily MeSH
• pyrazoly aplikace a dávkování   terapeutické užití   MeSH
• pyrimidiny 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
• Názvy látek
• biologické markery MeSH
• cytokiny MeSH
• inhibitory proteinkinas MeSH
• Janus kinasy MeSH
• nitrily MeSH
• pyrazoly MeSH
• pyrimidiny MeSH
• ruxolitinib MeSH Prohlížeč
• STAT1 protein, human MeSH Prohlížeč
• transkripční faktor STAT1 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.

• Klíčová slova
• Dendritic cells, Signaling, TBEV, Tick saliva,
• 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
• Názvy látek
• protoonkogenní proteiny c-akt MeSH
• transkripční faktor STAT1 MeSH