Neutrophil extracellular traps, B cells, and type I interferons contribute to immune dysregulation in hidradenitis suppurativa

2019 ◽  
Vol 11 (508) ◽  
pp. eaav5908 ◽  
Author(s):  
Angel S. Byrd ◽  
Carmelo Carmona-Rivera ◽  
Liam J. O’Neil ◽  
Philip M. Carlucci ◽  
Cecilia Cisar ◽  
...  

Hidradenitis suppurativa (HS), also known as acne inversa, is an incapacitating skin disorder of unknown etiology manifested as abscess-like nodules and boils resulting in fistulas and tissue scarring as it progresses. Given that neutrophils are the predominant leukocyte infiltrate in HS lesions, the role of neutrophil extracellular traps (NETs) in the induction of local and systemic immune dysregulation in this disease was examined. Immunofluorescence microscopy was performed in HS lesions and detected the prominent presence of NETs. NET complexes correlated with disease severity, as measured by Hurley staging. Neutrophils from the peripheral blood of patients with HS peripheral also displayed enhanced spontaneous NET formation when compared to healthy control neutrophils. Sera from patients recognized antigens present in NETs and harbored increased antibodies reactive to citrullinated peptides. B cell dysregulation, as evidenced by elevated plasma cells and IgG, was observed in the circulation and skin from patients with HS. Peptidylarginine deiminases (PADs) 1 to 4, enzymes involved in citrullination, were differentially expressed in HS skin, when compared to controls, in association with enhanced tissue citrullination. NETs in HS skin coexisted with plasmacytoid dendritic cells, in association with a type I interferon (IFN) gene signature. Enhanced NET formation and immune responses to neutrophil and NET-related antigens may promote immune dysregulation and contribute to inflammation. This, along with evidence of up-regulation of the type I IFN pathway in HS skin, suggests that the innate immune system may play important pathogenic roles in this disease.

2021 ◽  
Vol 14 (673) ◽  
pp. eaax7942
Author(s):  
Falko Apel ◽  
Liudmila Andreeva ◽  
Lorenz Sebastian Knackstedt ◽  
Robert Streeck ◽  
Christian Karl Frese ◽  
...  

Neutrophil extracellular traps (NETs) are structures consisting of chromatin and antimicrobial molecules that are released by neutrophils during a form of regulated cell death called NETosis. NETs trap invading pathogens, promote coagulation, and activate myeloid cells to produce type I interferons (IFNs), proinflammatory cytokines that regulate the immune system. Here, we showed that macrophages and other myeloid cells phagocytosed NETs. Once in phagosomes, NETs translocated to the cytosol, where the DNA backbones of these structures activated the innate immune sensor cyclic GMP-AMP synthase (cGAS) and induced type I IFN production. The NET-associated serine protease neutrophil elastase (NE) mediated the activation of this pathway. We showed that NET induction in mice treated with the lectin concanavalin A, a model of autoimmune hepatitis, resulted in cGAS-dependent stimulation of an IFN response, suggesting that NETs activated cGAS in vivo. Thus, our findings suggest that cGAS is a sensor of NETs, mediating immune cell activation during infection.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 542.2-542
Author(s):  
A. Avdeeva ◽  
E. Tchetina ◽  
G. Markova ◽  
E. Nasonov

Background:Type I interferons (IFN-Is) are a group of molecules with pleiotropic effects on the immune system forming a crucial link between innate and adaptive immune responses. The type I interferon pathway has been implicated in the pathogenesis of a number of rheumatic diseases, including rheumatoid arthritis. IFN activity is usually quantified using expression of interferon-stimulated genes (ISGs) referred to as an IFN signature. Acellbia (BIOCAD) is the first Russian rituximab (RTX) biosimilar which was approved for medical use in rheumatoid arthritis (RA) patients in Russia and some CIS countries.Objectives:To evaluate the changes in expression of ISGs in patients (pts) with RA during RTX biosimilar therapyMethods:20 RA pts (18 woman, Me;IQR age 61.5(54-66.5) years, disease duration 39.5(20-84) months, mean DAS 28 5.6(4.9-6.8)) received two intravenous RTX biosimilar infusions (600 mg №2) in combination with DMARDs and glucocorticoids. Laboratory biomarkers were assessed at baseline and 24 weeks after the first infusion of RTX. 5 genes (IFI44L, MX1, IFIT 1, RSAD2, EPSTI1) were selected for evaluation of the “interferon signature” (Type I IFN gene signature – IFNGS). IFI44L and IFIT1 expression was undetectable, therefore the remaining three genes (MSX1, EPSTI1, RSAD2) were included into further analysis. IFNGS was calculated as the average expression values of the three selected genes. The control group included 20 age and gender matching healthy donors.Results:The baseline expression levels of MX1-11.48 (5.45-19.38), EPSTI1-12.83 (5.62-19.64), RSAD2-5.16 (2.73-10.4), and IFNGS-10.3 (5.18-17.12) in RA patients were significantly higher compared to healthy donors– 1,26 (0,73-1,6); 1,06 (0,81-1,48); 0,93 (0,72-1,19); 1,09 (0,92-1,42), (p<0.05, respectively). IFNGS was detected in 15 (75%) patients, and was not found in 5 (15%) patients. RTX induced reduction in disease activity, and the level of acute phase reactants (ESR, CRP) after 12 and 24 weeks of therapy, p<0.05 (fig.1). Increased RSAD 2 expression (p<0.05) and a trend to increasing IFNGS levels (p=0.06) were documented in the whole group, and also in patients with moderate treatment effects by week 24. Among patients with a good EULAR response to therapy, changes in expression were not significant (p> 0.05) (fig.1)Figure 1.Conclusion:Expression of IFN-stimulated genes was increased in RA patients compared to healthy donors. Increased RSAD2 and IFNGS expression was documented in patients with moderate effect of RTX therapy, therefore, these findings have important clinical relevance as predictors of RA clinical course which necessitates personified approach to treatment.Disclosure of Interests:None declared


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1056.2-1057
Author(s):  
S. Bedina ◽  
E. Mozgovaya ◽  
A. Trofimenko ◽  
S. Spitsina ◽  
M. Mamus

Background:Rheumatoid arthritis (RA) is an autoimmune rheumatic disease of unknown etiology characterized by chronic erosive arthritis and systemic organ involvement resulting in early disability and shorter life expectancy. Neutrophils are suggested to play a substantial role in the induction and promotion of autoimmune inflammation in RA. This ability can be based on newly discovered feature of neutrophils to release neutrophil extracellular traps (NETs) during specific type cell death called NETosis. Hyperproduction of reactive oxygen species (ROS) is one of the factors promoting NETs production. With this background, the study of pro- and antioxidant enzymatic activities in RA patients can be of great interest.Objectives:To assess plasma activities of essential prooxidant and antioxidant enzymes in RA patients.Methods:The research was carried out in agreement with the WMA Declaration of Helsinki principles. 71 RA patients (46 women and 25 men) were enrolled in the study. The diagnosis was verified using ACR/EULAR criteria (2010). RA activity was measured using the Disease Activity Score of 28 joints (DAS28). 30 healthy persons comprise control group. Plasma xanthine oxidase (XO; ЕС 1.17.3.2), xanthine dehydrogenase (XDH; ЕС 1.17.1.4) and superoxide dismutase (SOD; ЕС 1.15.1.1) activities were measured using spectrophotometric technique. XO and XDG activities were expressed as nmol/ml/min, SOD activity – as units of action. Statistical analysis was performed using Statistica 6.0 software package. Differences were considered significant when p<0.05. Reference ranges were calculated as means ±2SD.Results:Mean age of patients was 43.2±3.6 years, mean RA duration was 11.9±2.6 years. 24 (33.8%) RA patients had low disease activity, and 6 (8.5%) patients had high one. Extra-articular manifestations were found in 30 (42.2%) patients. 30% of them had cardiovascular involvement, 23.3% – pulmonary lesions, and 23.3% had renal involvement. Reference ranges for XO, XDG, and SOD activities were 2.28-5.12 nmol/min/ml, 3,96-7,24 nmol/min/ml, and 3,13-6,58 units, respectively. We examined activities of these enzymes in circulation of RA patients with different patterns of clinical manifestations as well as relationship between RA activity and XO, XDG, and SOD activities. RA patients had increased both mean XO and mean SOD activities (p<0.001 for both enzymes). XO activity reached its highest values at maximum disease activity and overt extra-articular involvements, while SOD activity did it in moderate and high disease activities as well as in patients with joint manifestations. XDG activity was increased in low disease activity (р<0.001) and solely joint lesions (р=0.011), while moderate or high disease activities (р=0.008) and extra-articular involvements (р=0.025) were characterized by decreased activity of this enzyme.Conclusion:We have revealed substantial multidirectional changes of plasma XO and XDG activities in RA. Plasma enzymatic pattern in RA patients is characterized by activation of both oxidant and antioxidant metabolic pathways. Activities of XO and SOD were positively correlated with RA activity, while XDG activity was negative correlated with RA activity. The differences between selective articular RA type and RA form with extraarticular manifestations were also revealed. Changes in oxidant and antioxidant enzyme activities can be connected with anticitrulline autoimmunity in RA via production of citrulline-rich neutrophil extracellular traps, thus enhancing rheumatoid autoimmunity.Disclosure of Interests:None declared


2018 ◽  
Vol 138 (5) ◽  
pp. S173
Author(s):  
A.S. Byrd ◽  
C. Carmona-Rivera ◽  
P.A. Carlucci ◽  
M.L. Kerns ◽  
J.A. Caffrey ◽  
...  

Blood ◽  
2021 ◽  
Author(s):  
Ranran Wang ◽  
Yuanbo Zhu ◽  
Zhongwang Liu ◽  
Luping Chang ◽  
Xiaofei Bai ◽  
...  

Intracerebral hemorrhage associated with thrombolytic therapy with tissue plasminogen activator (tPA) in acute ischemic stroke continues to present a major clinical problem. Here, we report that infusion of tPA resulted in a significant increase in markers of neutrophil extracellular traps (NETs) in the ischemic cortex and plasma of mice subjected to photothrombotic middle cerebral artery occlusion. Peptidylarginine deiminase 4 (PAD4), a critical enzyme for NET formation, is also significantly upregulated in the ischemic brains in tPA-treated mice. Blood-brain barrier (BBB) disruption following ischemic challenge in an in vitro model of BBB was exacerbated after exposure to NETs. Importantly, disruption of NETs by DNase 1 or inhibition of NET production by PAD4 deficiency restored tPA-induced loss of BBB integrity and consequently decreased tPA-associated brain hemorrhage after ischemic stroke. Furthermore, either DNase 1 or PAD4 deficiency reversed tPA-mediated upregulation of the DNA sensor cyclic GMP-AMP (cGAMP) synthase (cGAS). Administration of cGAMP after stroke abolished DNase 1-mediated downregulation of the STING pathway and type I interferon (IFN) production, and blocked the antihemorrhagic effect of DNase 1 in tPA-treated mice. We also show that tPA-associated brain hemorrhage after ischemic stroke was significantly reduced in cGas-/- mice. Collectively, these findings demonstrate that NETs significantly contribute to tPA-induced BBB breakdown in ischemic brain, and suggest that targeting NETs or cGAS may ameliorate thrombolytic therapy for ischemic stroke by reducing tPA-associated hemorrhage.


Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 44
Author(s):  
Viktor A. Zouboulis ◽  
Konstantin C. Zouboulis ◽  
Christos C. Zouboulis

Chronic inflammation and dysregulated epithelial differentiation, especially of hair follicle keratinocytes, have been suggested as the major pathogenetic pathways of hidradenitis suppurativa/acne inversa (HS). On the other hand, obesity and metabolic syndrome have additionally been considered as an important risk factor. With adalimumab, a drug has already been approved and numerous other compounds are in advanced-stage clinical studies. A systematic review was conducted to detect and corroborate HS pathogenetic mechanisms at the molecular level and identify HS molecular markers. The obtained data were used to confirm studied and off-label administered drugs and to identify additional compounds for drug repurposing. A robust, strongly associated group of HS biomarkers was detected. The triad of HS pathogenesis, namely upregulated inflammation, altered epithelial differentiation and dysregulated metabolism/hormone signaling was confirmed, the molecular association of HS with certain comorbid disorders, such as inflammatory bowel disease, arthritis, type I diabetes mellitus and lipids/atherosclerosis/adipogenesis was verified and common biomarkers were identified. The molecular suitability of compounds in clinical studies was confirmed and 31 potential HS repurposing drugs, among them 10 drugs already launched for other disorders, were detected. This systematic review provides evidence for the importance of molecular studies to advance the knowledge regarding pathogenesis, future treatment and biomarker-supported clinical course follow-up in HS.


Author(s):  
Julie Desbarats

Although most cases of COVID-19 are paucisymptomatic, severe disease is characterized by immune dysregulation, with a decreased type I interferon response, increased inflammatory indicators, surging IL-6, IL-10 and TNF&alpha; suggestive of cytokine storm, progressive lymphopenia, and abnormal blood clotting. Factors determining susceptibility to severe disease are poorly understood, although mortality correlates with increasing age and co-morbidities including diabetes and cardiovascular disease (CVD). Pyridoxal 5'-phosphate (PLP) tends to be insufficient in populations particularly vulnerable to COVID-19, including the elderly, the institutionalized, and people with diabetes and CVD, and PLP becomes further depleted during infection and inflammation. In turn, low PLP results in immune imbalance, as PLP is an essential cofactor in pathways regulating cytokine production, in particular type I interferons and IL-6, and in lymphocyte trafficking and endothelial integrity. Furthermore, normalizing PLP levels attenuates abnormalities in platelet aggregation and clot formation. Finally, PLP insufficiency induces excess secretion of renin and angiotensin, and hypertension. In inflammatory disease, pharmacological doses of PLP decrease circulating TNF&alpha;, IL-6 and D-dimer, and animal studies demonstrate that supplemental PLP shortens the duration and severity of viral pneumonia. Severe COVID-19 manifests as an imbalance in the immune response and the clotting system. Pharmacological PLP supplementation may therefore mitigate COVID-19 symptoms by alleviating both the immune suppression underlying viral spread and the pathological hypersecretion of inflammatory cytokines, as well as directly bolstering endothelial integrity and preventing hypercoagulability.


2021 ◽  
Vol 10 (22) ◽  
pp. 5243
Author(s):  
Olga Ciepiela ◽  
Milena Małecka-Giełdowska ◽  
Emilia Czyżewska

Plasma cell dyscrasias (PCDs) are neoplastic diseases derived from plasma cells. Patients suffering from PCDs are at high risk of hypercoagulability and thrombosis. These conditions are associated with disease-related factors, patient-related factors, or the use of immunomodulatory drugs. As PCDs belong to neoplastic diseases, some other factors related to the cancer-associated hypercoagulability state in the course of PCDs are also considered. One of the weakest issues studied in PCDs is the procoagulant activity of neutrophil extracellular traps (NETs). NETs are web-like structures released from neutrophils in response to different stimuli. These structures are made of deoxyribonucleic acid (DNA) and bactericidal proteins, such as histones, myeloperoxidase, neutrophil elastase, and over 300 other proteins, which are primarily stored in neutrophil granules. NETs immobilize, inactivate the pathogens, and expose them to specialized cells of immune response. Despite their pivotal role in innate immunity, they contribute to the development and exacerbation of autoimmune diseases, trigger inflammatory response, or even facilitate the formation of cancer metastases. NETs were also found to induce activity of coagulation and are considered one of the most important factors inducing thrombosis. Here, we summarize how PCDs influence the release of NETs, and hypothesize whether NETs contribute to hypercoagulability in PCDs patients.


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