scholarly journals Clostridium difficile Toxin B activates the NLRP3 inflammasome in human macrophages, demonstrating a novel regulatory mechanism for the Pyrin inflammasome

2021 ◽  
Author(s):  
Matthew Stephen James Mangan ◽  
Friederike Gorki ◽  
Karoline Krause ◽  
Alexander Heinz ◽  
Thomas Ebert ◽  
...  

Pyrin is a cytosolic immune sensor that forms an inflammasome when bacterial virulence factors inhibit RhoA, triggering the release of inflammatory cytokines, including IL-1β. Gain of function mutations in the MEFV gene encoding Pyrin cause auto-inflammatory disorders, such as familial Mediterranean fever (FMF) and Pyrin associated auto-inflammation with Neutrophilic Dermatosis (PAAND). To precisely define the role of Pyrin in detecting pathogen virulence factors in relevant human immune cells, we investigated how the Pyrin inflammasome response was initiated and regulated in monocyte-derived macrophages (hMDM) compared to human monocytes. Unlike monocytes and murine macrophages, we determined that hMDM failed to activate Pyrin in response to known Pyrin activators Clostridioides difficile (C. difficile) toxins A or B (TcdA or TcdB). In contrast, TcdB activated the NLRP3 inflammasome in hMDM. Notably, we ascertained that the Pyrin inflammasome response could be re-enabled in hMDM by prolonged priming with either LPS or type I or II interferons, and required an increase in Pyrin expression. These data demonstrate an unexpected redundancy in detecting these toxins by inflammasome sensors.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Cigdem Yuce Kahraman ◽  
Mehmet Ertugrul Egin ◽  
Abdulgani Tatar ◽  
Hasan Turkez ◽  
Adil Mardinoglu

Familial Mediterranean fever (FMF) is the most prevalent autoinflammatory disease. Typical findings are recurrent fever attacks with serositis, skin rash, and synovitis. FMF is caused by mutations in the MEFV gene, encoding pyrin protein. Pyrin functions in innate immunity and triggers inflammation via inflammatory mediators’ production and acts as the primary regulatory component of the inflammasome. On the other hand, various miRNAs play crucial roles in the pathogenesis of different types of cancers and immune-related and neurodegenerative diseases. However, their association with FMF is still unclear. Therefore, in this study, we assessed the roles of selected thirteen miRNAs associated with immune functions. We recruited genetically diagnosed 28 FMF patients and 28 healthy individuals. The expression profiling of the miRNAs was determined by qRT-PCR and normalized to SNORD61. Our analysis revealed that miR-34a-5p, miR-142-3p, miR-216a-5p, miR-340-5p, miR-429, and miR-582-5p were upregulated, whereas miR-107, miR-569, and miR-1304-5p were downregulated in the FMF patients. Among them, miR-107 was found to be the most remarkable in M694V homozygous mutants compared to other homozygous mutants. During clinical follow-up of the patients with M694V mutation, which is closely related to amyloidosis, evaluation of mir-107 expression might be crucial and suggestive. Our results showed that miRNAs might serve a function in the pathogenesis of FMF. Further studies may provide novel and effective diagnostic and therapeutic agents that target examined miRNAs. Targeting miRNAs in FMF seems to be promising and may yield a new generation of rational therapeutics and diagnostic or monitoring tools enabling FMF treatment.


2016 ◽  
Vol 8 (332) ◽  
pp. 332ra45-332ra45 ◽  
Author(s):  
Seth L. Masters ◽  
Vasiliki Lagou ◽  
Isabelle Jéru ◽  
Paul J. Baker ◽  
Lien Van Eyck ◽  
...  

Pyrin responds to pathogen signals and loss of cellular homeostasis by forming an inflammasome complex that drives the cleavage and secretion of interleukin-1β (IL-1β). Mutations in the B30.2/SPRY domain cause pathogen-independent activation of pyrin and are responsible for the autoinflammatory disease familial Mediterranean fever (FMF). We studied a family with a dominantly inherited autoinflammatory disease, distinct from FMF, characterized by childhood-onset recurrent episodes of neutrophilic dermatosis, fever, elevated acute-phase reactants, arthralgia, and myalgia/myositis. The disease was caused by a mutation in MEFV, the gene encoding pyrin (S242R). The mutation results in the loss of a 14-3-3 binding motif at phosphorylated S242, which was not perturbed by FMF mutations in the B30.2/SPRY domain. However, loss of both S242 phosphorylation and 14-3-3 binding was observed for bacterial effectors that activate the pyrin inflammasome, such as Clostridiumdifficile toxin B (TcdB). The S242R mutation thus recapitulated the effect of pathogen sensing, triggering inflammasome activation and IL-1β production. Successful therapy targeting IL-1β has been initiated in one patient, resolving pyrin-associated autoinflammation with neutrophilic dermatosis. This disease provides evidence that a guard-like mechanism of pyrin regulation, originally identified for Nod-like receptors in plant innate immunity, also exists in humans.


1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  

PEDIATRICS ◽  
2001 ◽  
Vol 108 (1) ◽  
pp. 215-215 ◽  
Author(s):  
N. Akar ◽  
E. Akar ◽  
F. Yalcinkaya; ◽  
G. J. Halpern ◽  
A. Mimouni ◽  
...  

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1417.1-1417
Author(s):  
M. Osipyan ◽  
M. Efraimidou ◽  
V. Vardanyan ◽  
K. Ginosyan

Background:Numerous joint disorders initially produce swelling in a single joint and new onset monoartritis will probably further lead to the involvement of other joint groups and development of extraarticular manifestations. It is essential to take a proper diagnostic approach for organizing appropriate treatment and lowering possibility of disease progression.Objectives:The aim of this study was to investigate joint distribution, determine rheumatological diseases of patients with acute monoarthritis and reveal the development of further systemic manifestations.Methods:100 patients (age 18-75 years) with clinically apparent monoarthritis of less than 6 weeks duration were included in the study. Criteria of exclusion were infection, trauma and crystal induced arthritis. Joint distribution, presence of systemic manifestations and development of chronic inflammatory rheumatic disease were evaluated. Presence of arthritis was proved with help of ultrasound examination. Complete blood count, ESR, CRP, RF, anti-CCP; HLAB27; MEFV mutations and X-ray of swollen joint were performed for all patients. Temperature was also measured.Results:Mean age of patients with acute monoarthritis was 46±13 years. Female predominance was noted (61%). 71% of patients had elevated ESR, 69%- CRP. In 24% of cases homozygous or heterozygous mutations of MEFV gene were revealed. 21% of patients had positive RF and 18% - anti-CCP. 11% patients carried HLA-B27 antigen. 28% of examined patients had subfebril fever. Hepatosplenomegaly was determined in 16%, uveitis in 5%, psoriatic plaque in 4%, interstitial pneumonia in 2% of casesAt the baseline 82 patients were diagnosed with rheumatologically disease. Baseline data is shown in the Table 1 bellow.Table 1.Baseline dataDiagnosis Number of patientsFMF23Osteoarthritis (reactive synovitis)16Rheumatoid arthritis15Reactive arthritis10Ankylosing spondylitis6Psoriatic arthritis4SLE3Schonleyn-Henoch purpura2Sarcoidosis2Behcet diseases1Conclusion:In this study monoarhtritis in majority of cases underlies FMF. Though FMF is not considered as a frequent cause of acute monoarthritis, more attention should be paid on this pathology in focus of monoarthritis, especially in specific for FMF region. Further follow up of acute monoarthritis progression is needed.References:[1]A. Becker, J. Daily, K. Pohlgeers. Acute Monoarthritis: Diagnosis in Adults.Am Fam Physician 2016; 94(10): 810-816[2]S. Camacho-Lovillo, A. García-Martínez. Arthritis as presentation of familial Mediterranean fever. An Pediatr (Barc). 2015; 83(2):130. DOI: 10.1016/j.anpede.2015.07.007[3]J. Ellis. Acute monoarthritis. JAAPA. 2019, 32(3):25-31. doi: 0.1097/01.JAA.0000553379.52389.ebDisclosure of Interests:None declared


2021 ◽  
Vol 11 (6) ◽  
pp. 526
Author(s):  
Yejin Lee ◽  
Youn Jung Kim ◽  
Hong-Keun Hyun ◽  
Jae-Cheoun Lee ◽  
Zang Hee Lee ◽  
...  

Hereditary dentin defects can be categorized as a syndromic form predominantly related to osteogenesis imperfecta (OI) or isolated forms without other non-oral phenotypes. Mutations in the gene encoding dentin sialophosphoprotein (DSPP) have been identified to cause dentinogenesis imperfecta (DGI) Types II and III and dentin dysplasia (DD) Type II. While DGI Type I is an OI-related syndromic phenotype caused mostly by monoallelic mutations in the genes encoding collagen type I alpha 1 chain (COL1A1) and collagen type I alpha 2 chain (COL1A2). In this study, we recruited families with non-syndromic dentin defects and performed candidate gene sequencing for DSPP exons and exon/intron boundaries. Three unrelated Korean families were further analyzed by whole-exome sequencing due to the lack of the DSPP mutation, and heterozygous COL1A2 mutations were identified: c.3233G>A, p.(Gly1078Asp) in Family 1 and c.1171G>A, p.(Gly391Ser) in Family 2 and 3. Haplotype analysis revealed different disease alleles in Families 2 and 3, suggesting a mutational hotspot. We suggest expanding the molecular genetic etiology to include COL1A2 for isolated dentin defects in addition to DSPP.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1784.1-1784
Author(s):  
R. Dos Santos Sobrín ◽  
M. Martí Masanet ◽  
B. Lopez-Montesinos ◽  
L. Lacruz Pérez ◽  
I. Calvo

Background:Familial Mediterranean Fever (FMF) is a genetic autoinflammatory disorder caused mostly by mutations in MEFV gene. Its inheritance is autosomal recessive and is the most frequent periodic fever syndrome. First-line treatment is based in colchicine use, so biologics (anti-IL-1) are reserved for refractory cases1, 2.Objectives:To account for clinic and treatment features of patients with FMF in a specialized center as opposed to non-referent centers.Methods:This study was developed in the Pediatric Rheumatology Service in Hospital Universitario y Politécnico La Fe de Valencia. Demographic, clinic and treatment data were collected from patients diagnosed of FMF since January 2004 to September 2019.Results:106 patients met last FMF criteria3. 55% had a pathogenic mutation in genetic analysis. 52% were female. Before 10 years old, 71% of patients had the diagnosis (51% before 4 years old). Arthralgia/myalgia (73%), periodic fever (62%) and abdominal pain (54%) were the most common symptoms. Systemic Juvenile Idiopathic Arthritis (JIA, 6), other forms of JIA (9) and vasculitis (10) were the most prevalent comorbidities. When talking about treatment, 76,4% received Colchicine (60,5% with good response), 22,6% needed a classical disease modifying antirheumatic drug (mostly Methotrexate) and 22 patients got biologic treatment (73% anti-IL-1).Conclusion:When analyzing this case-review, JIA has a strong association with our patients, so it could explain severe disease activity and more articular involvement. This could be an illustration to the higher use of Methotrexate. Also, the most relevant symptom was arthralgia while fever is the most frequent in literature. Likewise, age of diagnosis has been earlier than other case-series (this would be more frequent in other autoinflammatory syndromes, as literature relates)1, 2, 4.References:[1]Ozdogan H, Ugurlu S. Familial Mediterranean Fever. Presse Med. (2019).[2]Ozen S, Demirkaya E, Erer B, et al. EULAR recommendations for the management of familial Mediterranean fever. Ann Rheum Dis 2016;75:644-651.[3]Sag E, Demirel D, Demir S, et al. Performance of the new “Eurofever/PRINTO classification criteria” in FMF patients. Semin Arthritis Rheum. 2019;19:30369-5.[4]Rozenbaum M, Rosner I. Severe outcome of juvenile idiopathic arthritis (JIA) associated with familial Mediterranean fever (FMF). Clin Exp Rheumatol. 2004;22:S75-8.Disclosure of Interests:Raquel Dos Santos Sobrín: None declared, Miguel Martí Masanet: None declared, B Lopez-Montesinos: None declared, Lucía Lacruz Pérez: None declared, Inmaculada Calvo Grant/research support from: Bristol-Myers Squibb, Clementia, GlaxoSmithKline, Hoffman-La Roche, Merck Sharpe & Dohme, Novartis, Pfizer, Sanofi, Speakers bureau: AbbVie, GlaxoSmithKline, Hoffman-La Roche, Novartis


2012 ◽  
Vol 18 (9) ◽  
pp. 1229-1238 ◽  
Author(s):  
T Kümpfel ◽  
L-A Gerdes ◽  
T Wacker ◽  
A Blaschek ◽  
J Havla ◽  
...  

Background: Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease caused by mutations in the MEFV gene and characterized by recurrent febrile polyserositis. A possible association of FMF and multiple sclerosis (MS) has been suggested in cohorts from Turkey and Israel. Objective: The objective of this study was to investigate the prevalence of MEFV mutations in subjects with MS and in controls in Germany. Methods: One-hundred and fifty seven MS patients with at least one symptom or without symptoms suggestive of FMF from our outpatient clinic were investigated for mutations in exons 2, 3, and 10 of the MEFV gene (group 1). 260 independent MS patients (group 2) and 400 unrelated Caucasian controls (group 3) were screened selectively for the low-penetrance pyrin mutations E148Q and K695R Results: In group 1, 19 MS patients (12.1%) tested positive for a mutation in the MEFV gene, mainly the E148Q ( n=7) substitution. Fifteen of the 19 mutation-positive individuals reported at least one symptom suggestive of FMF. In three cases, we could identify additional family members with MS. In these pedigrees, the E148Q exchange co-segregated with MS ( p=0.026). Frequencies of the pyrin E148Q and K695R mutations were not statistically different between MS group 2 and controls but they occurred with a surprisingly high frequency in the German population. Conclusion: The MEFV gene appears to be another immunologically relevant gene locus which contributes to MS susceptibility. In particular, the pyrin E148Q mutation, which co-segregated with disease in three MS families, is a promising candidate risk factor for MS that should be further explored in larger studies.


2013 ◽  
Vol 20 (11) ◽  
pp. 1703-1710 ◽  
Author(s):  
Luca Formichella ◽  
Laura Romberg ◽  
Christian Bolz ◽  
Michael Vieth ◽  
Michael Geppert ◽  
...  

ABSTRACTHelicobacter pyloricolonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome.H. pylorivirulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to importantH. pylorivirulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed inEscherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) wereH. pylorinegative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), therecomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, therecomLine assay provides a valuable tool for the diagnosis ofH. pyloriinfection.


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