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.

• 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

The aim of this study was to investigate the impact of thymic dysplasia on the phenotypic and functional characteristics of T cells in patients with 22q11.2 deletion syndrome, including T-cell phenotype, transcriptional profile, cytokine production, as well as the possibility of utilizing IL-7 to recover their numbers and function. We found a strong bias towards Th1 response in pediatric and young adult 22q11.2DS patients, expansion of CXCR5+ follicular helper cells and CXCR3+CCR6- Th1 cells, increased production of cytokines IFN-γ, IL-10, IL-2, IL-21 and TNF-α. This Th1 skew was primarily driven by expanded terminally differentiated T cells. IL-7 further reduced naive T cells, increased cytokine production and caused an upregulation of exhaustion markers. Thus, Th1 bias in T cell populations persists from infancy into adolescence and is accompanied by accelerated maturation of T cells into memory stages. This phenotype is exacerbated by IL-7 which causes further decrease in naïve T cells in vitro.

• MeSH
• cytokiny MeSH
• DiGeorgeův syndrom * MeSH
• dítě MeSH
• interferon gama * MeSH
• interleukin-7 MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• paměťové T-buňky MeSH
• Th1 buňky MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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

• Publikační typ
• abstrakt z konference MeSH

Type 1 diabetes (T1D) is an autoimmune disorder with unambiguous involvement of both innate and adaptive immune mechanisms in the destruction of pancreatic beta cells. Recent evidence demonstrated that neutrophils infiltrate the pancreas prior to disease onset and therein extrude neutrophil extracellular traps (NETs), web-like structures of DNA and nuclear proteins with a strong pro-inflammatory biologic activity. Our previous work showed that T1D NETs activate dendritic cells, which consequently induce IFNγ-producing Th1 lymphocytes. The aim of this study was to assess direct ex vivo biomarkers of NETosis in the serum of recent onset and long-term pediatric T1D patients, their first-degree relatives and healthy controls. To this end we evaluated serum levels of myeloperoxidase (MPO), neutrophil elastase (NE), proteinase 3 (PR3), protein arginine deiminase 4 (PAD4), LL37 and cell-free DNA-histone complexes in sex- and age-matched cohorts of T1D first-degree relatives, recent-onset T1D patients, and in patients 12 months after clinical manifestation of the disease. Our data shows that disease onset is accompanied by peripheral neutrophilia and significant elevation of MPO, NE, PR3, PAD4 and cell-free DNA-histone complexes. Most biomarkers subsequently decrease but do not always normalize in long-term patients. First-degree relatives displayed an intermediate phenotype, except for remarkably high levels of LL37. Together, this report provides evidence for the presence of ongoing NETosis in pediatric patients with T1D at time of clinical manifestation of the disease, which partly subsides in subsequent years.

• MeSH
• biologické markery krev   MeSH
• diabetes mellitus 1. typu krev   imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• extracelulární pasti * MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• neutrofily imunologie   MeSH
• předškolní dítě MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Blau syndrome (BS) is an auto-inflammatory granulomatous disease that possibly involves abnormal response to interferon gamma (IFNγ) due to exaggerated nucleotide-binding oligomerization domain containing 2 (NOD2) activity. Mendelian susceptibility to mycobacterial diseases (MSMD) is an infectious granulomatous disease that is caused by impaired production of or response to IFNγ. We report a mother and daughter who are both heterozygous for NOD2c.2264C˃T variant and dominant-negative IFNGR1818del4 mutation. The 17-year-old patient displayed an altered form of BS and milder form of MSMD, whereas the 44-year-old mother was completely asymptomatic. This experiment of nature supports the notion that IFNγ is an important driver of at least some BS manifestations and that elucidation of its involvement in the disease immunopathogenesis may identify novel therapeutic targets.

• MeSH
• artritida genetika   MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mutace genetika   MeSH
• receptory interferonů nedostatek   genetika   MeSH
• sarkoidóza genetika   MeSH
• signální adaptorový protein Nod2 genetika   MeSH
• synovitida genetika   MeSH
• uveitida genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

COVID-19, caused by SARS-CoV-2 virus, emerged as a pandemic disease posing a severe threat to global health. To date, sporadic studies have demonstrated that innate immune mechanisms, specifically neutrophilia, NETosis, and neutrophil-associated cytokine responses, are involved in COVID-19 pathogenesis; however, our understanding of the exact nature of this aspect of host-pathogen interaction is limited. Here, we present a detailed dissection of the features and functional profiles of neutrophils, dendritic cells, and monocytes in COVID-19. We portray the crucial role of neutrophils as drivers of hyperinflammation associated with COVID-19 disease via the shift towards their immature forms, enhanced degranulation, cytokine production, and augmented interferon responses. We demonstrate the impaired functionality of COVID-19 dendritic cells and monocytes, particularly their low expression of maturation markers, increased PD-L1 levels, and their inability to upregulate phenotype upon stimulation. In summary, our work highlights important data that prompt further research, as therapeutic targeting of neutrophils and their associated products may hold the potential to reduce the severity of COVID-19.

• MeSH
• antigeny CD274 genetika   metabolismus   MeSH
• COVID-19 MeSH
• cytokiny genetika   metabolismus   MeSH
• dendritické buňky imunologie   MeSH
• dospělí MeSH
• imunofenotypizace MeSH
• koronavirové infekce krev   imunologie   MeSH
• kultivované buňky MeSH
• lidé středního věku MeSH
• lidé MeSH
• monocyty imunologie   MeSH
• neutrofily imunologie   MeSH
• pandemie MeSH
• přirozená imunita MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• virová pneumonie krev   imunologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This study aimed to assess the key laboratory features displayed by coronavirus disease 2019 (COVID-19) inpatients that are associated with mild, moderate, severe, and fatal courses of the disease, and through a longitudinal follow-up, to understand the dynamics of the COVID-19 pathophysiology. All severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients admitted to the University Hospital in Motol between March and June 2020 were included in this study. A severe course of COVID-19 was associated with an elevation of proinflammatory markers; an efflux of immature granulocytes into peripheral blood; the activation of CD8 T cells, which infiltrated the lungs; transient liver disease. In particular, the elevation of serum gamma-glutamyl transferase (GGT) and histological signs of cholestasis were highly specific for patients with a severe form of the disease. In contrast, patients with a fatal course of COVID-19 failed to upregulate markers of inflammation, showed discoordination of the immune response, and progressed toward acute kidney failure. COVID-19 is a disease with a multi-organ affinity that is characterized by the activation of innate and cellular adaptive immunity. Biliary lesions with an elevation of GGT and the organ infiltration of interleukin 6 (IL-6)-producing cells are the defining characteristics for patients with the fulminant disease.

• Publikační typ
• časopisecké články MeSH

První zprávy o interleukinu 27 (IL-27), jeho receptoru (IL-27R), jednotlivých složkách a signalizačních drahách se objevily přibližně před 20 lety. Přesto není jeho role a funkce v imunitním systému při fyziologickém i patologickém stavu stále přesně definována. IL-27 je produkován aktivovanými antigen prezentujícími buňkami (APC). Váže se na IL-27R, který je exprimován jak na imunitních, tak neimunitních buňkách. Aktivita tohoto cytokinu reguluje adaptivní i vrozenou imunitu a hraje důležitou roli zejména v diferenciaci CD4+ T buněk. Podrobnější prozkoumání biologické úlohy a vlivu IL-27 na jednotlivé populace buněk by mohlo vést k lepšímu pochopení patofyziologie autoimunitních onemocnění, role cytokinové signalizace při jejich rozvoji, nebo k odhalení potenciálních terapeutických cílů.

First reports of interleukin 27 (IL-27), its receptor (IL-27R), their individual components and signaling pathways appeared approximately 20 years ago, however, its role and function in the immune system in both physiological and pathological conditions is still not fully defined. IL-27 is produced by activated antigen presenting cells (APC). It binds to IL-27R, which is expressed on both immune and non-immune cells. The activity of this cytokine regulates adaptive and innate immunity and plays an important role especially in the differentiation of CD4 + T cells. A detailed examination of the biological role and the effect of IL-27 on individual cellular populations could lead to a better understanding of the pathophysiology of autoimmune diseases, the role of cytokine signaling in their development, or the identification of potential therapeutic targets.

• MeSH
• autoimunitní nemoci etiologie   patofyziologie   MeSH
• cytokiny fyziologie   škodlivé účinky   MeSH
• diabetes mellitus 1. typu etiologie   patofyziologie   MeSH
• interleukin 27 * fyziologie   škodlivé účinky   MeSH
• lidé MeSH
• psoriáza etiologie   patofyziologie   MeSH
• revmatoidní artritida etiologie   patofyziologie   MeSH
• Check Tag
• lidé MeSH

X-linked inhibitor of apoptosis (XIAP) is the most potent human inhibitor of apoptosis, and is also involved in NOD2-dependent NFκB and MAPK signalling cascade activation. The absence or defective function of XIAP leads to the development of a rare and severe primary immunodeficiency known as X-linked lymphoproliferative syndrome type 2 (XLP-2), which is characterized by a triad of clinical manifestations, including a high incidence of haemophagocytic lymphohistiocytosis (HLH), lymphoproliferation and inflammatory bowel disease (IBD), usually with very early onset. Here, we present a novel XIAP mutation identified in a patient with atypical adult-onset IBD complicated by relapsing HLH, splenomegaly and sarcoid-like disease. The c.266delA mutation in the XIAP gene creates a premature stop codon, and causes a severe reduction in XIAP protein expression. The mutation is also associated with impaired spontaneous and staurosporine- and PMA-induced apoptosis accompanied by significantly increased expression of pro-apoptotic genes. We also confirmed the negative impact of this particular XIAP mutation on NOD2-dependent NFκB and MAPK activation, while NOD2-independent activation was found to be unaffected. Moreover, we assume that the mutation has an impact on the overproduction of IL-12 and IFNγ, the shift towards the Th1 immune response and increased numbers of central memory and effector memory CD4+ and CD8+ T cells. All these changes contribute to immune dysregulation and the clinical manifestation of XLP-2.

• MeSH
• apoptóza MeSH
• Crohnova nemoc genetika   patologie   MeSH
• dospělí MeSH
• lidé MeSH
• mutace MeSH
• signální adaptorový protein Nod2 metabolismus   MeSH
• signální transdukce MeSH
• X-vázaný inhibitor apoptózy metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH