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1.
Rheumatology (Oxford) ; 58(Supplement_6): vi31-vi43, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31769858

RESUMO

The systemic autoinflammatory diseases are disorders of the innate immune system distinguished by severe inflammation resulting from dysregulation of the innate immune system. Hereditary fever syndromes, such as FMF, TNF receptor-associated periodic syndrome, cryopyrin-associated periodic syndromes and mevalonate kinase deficiency, were the first group of systemic autoinflammatory diseases for which a genetic basis was established, between 1999 and 2001. Currently according to the latest report of the international union of immunological societies, 37 separate monogenic disorders were classified as autoinflammatory. In addition to the abovementioned monogenic conditions, we describe Schnitzler's syndrome, a well-defined, acquired autoinflammatory condition without a clear genetic basis. For the purposes of this review, we discuss several conditions defined by the latest consensus process as systemic autoinflammatory diseases. We focus on those disorders where recent studies have contributed to further phenotypic characterization or had an impact on clinical management.

2.
N Engl J Med ; 381(14): 1321-1332, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31577874

RESUMO

BACKGROUND: In the majority of patients with chronic spontaneous urticaria, most currently available therapies do not result in complete symptom control. Ligelizumab is a next-generation high-affinity humanized monoclonal anti-IgE antibody. Data are limited regarding the dose-response relationship of ligelizumab and the efficacy and safety of ligelizumab as compared with omalizumab and placebo in patients who have moderate-to-severe chronic spontaneous urticaria that is inadequately controlled with H1-antihistamines at approved or increased doses, alone or in combination with H2-antihistamines or leukotriene-receptor antagonists. METHODS: In a phase 2b dose-finding trial, we randomly assigned patients to receive ligelizumab at a dose of 24 mg, 72 mg, or 240 mg, omalizumab at a dose of 300 mg, or placebo, administered subcutaneously every 4 weeks for a period of 20 weeks, or a single 120-mg dose of ligelizumab. Disease symptoms of hives, itch, and angioedema were monitored by means of weekly activity scores. The main objective was to determine a dose-response relationship for the complete control of hives (indicated by a weekly hives-severity score of 0, on a scale from 0 to 21, with higher scores indicating greater severity); the primary end point of this response was assessed at week 12. Complete symptom control was indicated by a weekly urticaria activity score of 0 (on a scale from 0 to 42, with higher scores indicating greater severity). Safety was analyzed throughout the trial. RESULTS: A total of 382 patients underwent randomization. At week 12, a total of 30%, 51%, and 42% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of hives, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. A dose-response relationship was established. At week 12, a total of 30%, 44%, and 40% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of symptoms, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. In this small and short trial, no safety concerns regarding ligelizumab or omalizumab emerged. CONCLUSIONS: A higher percentage of patients had complete control of symptoms of chronic spontaneous urticaria with ligelizumab therapy of 72 mg or 240 mg than with omalizumab or placebo. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT02477332.).


Assuntos
Antialérgicos/administração & dosagem , Anticorpos Anti-Idiotípicos/administração & dosagem , Anticorpos Monoclonais Humanizados/administração & dosagem , Omalizumab/administração & dosagem , Urticária/tratamento farmacológico , Adulto , Idoso , Antialérgicos/efeitos adversos , Anticorpos Anti-Idiotípicos/efeitos adversos , Anticorpos Monoclonais Humanizados/efeitos adversos , Doença Crônica , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Omalizumab/efeitos adversos , Gravidade do Paciente , Indução de Remissão , Urticária/imunologia , Adulto Jovem
3.
Elife ; 82019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31532390

RESUMO

Cystic Fibrosis (CF) is a monogenic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, resulting in defective CFTR-mediated chloride and bicarbonate transport, with dysregulation of epithelial sodium channels (ENaC). These changes alter fluid and electrolyte homeostasis and result in an exaggerated proinflammatory response driven, in part, by infection. We tested the hypothesis that NLRP3 inflammasome activation and ENaC upregulation drives exaggerated innate-immune responses in this multisystem disease. We identify an enhanced proinflammatory signature, as evidenced by increased levels of IL-18, IL-1ß, caspase-1 activity and ASC-speck release in monocytes, epithelia and serum with CF-associated mutations; these differences were reversed by pretreatment with NLRP3 inflammasome inhibitors and notably, inhibition of amiloride-sensitive sodium (Na+) channels. Overexpression of ß-ENaC, in the absence of CFTR dysfunction, increased NLRP3-mediated inflammation, indicating that dysregulated, ENaC-dependent signalling may drive exaggerated inflammatory responses in CF. These data support a role for sodium in modulating NLRP3 inflammasome activation.

4.
Front Immunol ; 10: 1789, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428093

RESUMO

Cystic Fibrosis (CF) is a recessive genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR mutations cause dysregulation of channel function with intracellular accumulation of misfolded proteins and endoplasmic reticulum (ER) stress, with activation of the IRE1α-XBP1 pathway that regulates a subset of unfolded protein response (UPR) genes. This pathway regulates a group of genes that control proinflammatory and metabolic responses in different immune cells; however, the metabolic state of immune cells and the role of this pathway in CF remain elusive. Our results indicate that only innate immune cells from CF patients present increased levels of ER stress, mainly affecting neutrophils, monocytes, and macrophages. An overactive IRE1α-XBP1 pathway reprograms CF M1 macrophages toward an increased metabolic state, with increased glycolytic rates and mitochondrial function, associated with exaggerated production of TNF and IL-6. This hyper-metabolic state, seen in CF macrophages, is reversed by inhibiting the RNase domain of IRE1α, thereby decreasing the increased glycolic rates, mitochondrial function and inflammation. Altogether, our results indicate that innate immune cells from CF patients are primarily affected by ER stress. Moreover, the IRE1α-XBP1 pathway of the UPR is responsible for the hyper-metabolic state seen in CF macrophages, which is associated with the exaggerated inflammatory response. Modulating ER stress, metabolism and inflammation, by targeting IRE1α, may improve the metabolic fitness of macrophages, and other immune cells in CF and other immune-related disorders.

5.
J Clin Immunol ; 39(7): 688-701, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31388879

RESUMO

While widespread genome sequencing ushers in a new era of preventive medicine, the tools for predictive genomics are still lacking. Time and resource limitations mean that human diseases remain uncharacterized because of an inability to predict clinically relevant genetic variants. A strategy of targeting highly conserved protein regions is used commonly in functional studies. However, this benefit is lost for rare diseases where the attributable genes are mostly conserved. An immunological disorder exemplifying this challenge occurs through damaging mutations in RAG1 and RAG2 which presents at an early age with a distinct phenotype of life-threatening immunodeficiency or autoimmunity. Many tools exist for variant pathogenicity prediction, but these cannot account for the probability of variant occurrence. Here, we present a method that predicts the likelihood of mutation for every amino acid residue in the RAG1 and RAG2 proteins. Population genetics data from approximately 146,000 individuals was used for rare variant analysis. Forty-four known pathogenic variants reported in patients and recombination activity measurements from 110 RAG1/2 mutants were used to validate calculated scores. Probabilities were compared with 98 currently known human cases of disease. A genome sequence dataset of 558 patients who have primary immunodeficiency but that are negative for RAG deficiency were also used as validation controls. We compared the difference between mutation likelihood and pathogenicity prediction. Our method builds a map of most probable mutations allowing pre-emptive functional analysis. This method may be applied to other diseases with hopes of improving preparedness for clinical diagnosis.

6.
Arthritis Rheumatol ; 71(12): 2121-2125, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31268627

RESUMO

OBJECTIVE: To assess the prevalence of the MYD88 L265P mutation and variants within NLRP3 and evaluate the status of oligoclonal hematopoiesis in 30 patients with Schnitzler syndrome (SchS). METHODS: Thirty patients with SchS were recruited from 3 clinical centers. Six patients with known acquired cryopyrin-associated periodic syndromes (aCAPS) were included as controls. Allele-specific oligonucleotide-polymerase chain reaction was used for the detection of the MYD88 L265P variant, next-generation sequencing was applied to analyze NLRP3 and 28 genes associated with myelodysplastic syndrome, and gene scanning was performed for the detection of X chromosome inactivation. RESULTS: Activating NLRP3 mutations were not present in 11 SchS patients who had not been sequenced for this gene previously. The MYD88 L265P variant was present in 9 of 30 SchS patients, and somatic mutations associated with clonal hematopoiesis were identified in 1 of 30 patients with SchS and 1 of 6 patients with aCAPS. Evidence of nonrandom X chromosome inactivation was detected in 1 female patient with SchS and 1 female patient with aCAPS. CONCLUSION: A shared molecular mechanism accounting for the pathogenesis of inflammation in SchS remains elusive. Clonal hematopoiesis is not associated with other somatic mutations found in individuals with SchS or aCAPS.

7.
Br J Anaesth ; 123(1): e50-e64, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31130272

RESUMO

Suspected perioperative allergic reactions are rare but can be life-threatening. The diagnosis is difficult to make in the perioperative setting, but prompt recognition and correct treatment is necessary to ensure a good outcome. A group of 26 international experts in perioperative allergy (anaesthesiologists, allergists, and immunologists) contributed to a modified Delphi consensus process, which covered areas such as differential diagnosis, management during and after anaphylaxis, allergy investigations, and plans for a subsequent anaesthetic. They were asked to rank the appropriateness of statements related to the immediate management of suspected perioperative allergic reactions. Statements were selected to represent areas where there is a lack of consensus in existing guidelines, such as dosing of epinephrine and fluids, the management of impending cardiac arrest, and reactions refractory to standard treatment. The results of the modified Delphi consensus process have been included in the recommendations on the management of suspected perioperative allergic reactions. This paper provides anaesthetists with an overview of relevant knowledge on the immediate and postoperative management of suspected perioperative allergic reactions based on current literature and expert opinion. In addition, it provides practical advice and recommendations in areas where consensus has been lacking in existing guidelines.


Assuntos
Hipersensibilidade Imediata/terapia , Complicações Intraoperatórias/terapia , Complicações Pós-Operatórias/terapia , Humanos , Hipersensibilidade Imediata/diagnóstico , Internacionalidade , Complicações Intraoperatórias/diagnóstico , Complicações Pós-Operatórias/diagnóstico
8.
Arthritis Rheumatol ; 71(11): 1812-1823, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31131994

RESUMO

OBJECTIVE: To evaluate predictors of serious infection events (SIEs) during rituximab (RTX) therapy and effects of hypogammaglobulinemia on SIE rates, and humoral response and its persistence after discontinuation of RTX in the treatment of rheumatic and musculoskeletal diseases (RMDs). METHODS: A retrospective longitudinal study of 700 RMD patients treated with RTX in a single center was conducted. Immunoglobulin levels were measured at baseline and at 4-6 months after each treatment cycle. Baseline predictors of SIEs were assessed using multivariable logistic regression; for RTX cycles 2-4, a mixed-effects logistic regression model was used. RESULTS: A total of 507 patients (72%) had rheumatoid arthritis, 94 (13%) had systemic lupus erythematosus, 49 (7%) had antineutrophil cytoplasmic antibody-associated vasculitis, and 50 (7%) had other RMDs. The number of SIEs recorded was 281 in 176 patients (9.8 per 100 person-years). Predictors of SIEs included non-RTX-specific comorbidities (previous history of SIE, cancer, chronic lung disease, diabetes mellitus, and heart failure), higher corticosteroid dose, and RTX-specific factors, including low IgG (<6 gm/liter) both at baseline and during treatment, RTX-associated neutropenia, higher IgM, and longer time to RTX re-treatment, but not B cell count or depletion status. Of 110 patients with low IgG, SIE rates were higher in those with low IgG at baseline (16.4 per 100 person-years) and in those who acquired low IgG during or after RTX treatment (21.3 per 100 person-years) versus those with normal IgG (9.7 per 100 person-years). Five of 8 patients (63%) had impaired humoral response to pneumococcus and hemophilus following vaccination challenge, and only 4 of 11 patients (36%) had IgG normalized after switching biologic disease-modifying antirheumatic drugs. CONCLUSION: Immunoglobulin levels should be monitored at baseline and before each RTX cycle to identify patients at risk of SIEs. Individualized risk-benefit assessment should be undertaken in those with lower IgG as this is a consistent SIE predictor and may increase infection profiles when RTX is switched to different therapies.

9.
Clin Immunol ; 203: 23-27, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30953794

RESUMO

Genetic studies are identifying an increasing number of monogenic causes of Common Variable Immunodeficiency (CVID). Pathogenic variants in the C-terminus of NFKB2 have been identified in the subset of CVID patients whose immunodeficiency is associated with ectodermal dysplasia and central adrenal insufficiency. We describe 2 unrelated CVID pedigrees with 4 cases of pathogenic stop gain variants (c.1903C > T) in the ankyrin repeat domain (ARD) of NF-κB2, leading to a premature truncation of the protein at p.Arg635Term (R635X). By immunophenotyping and functional ex vivo B- and T-cell experiments we characterized the variant by reduced class-switched memory B-cell counts and immature plasmablasts, unable to produce IgG and IgA. Features of a poor proliferative T-cell response and reduced expansion of CD4+CXCR5+ T cells was only observed in the two clinically affected index cases without any clear clinical correlate. In conclusion, pathogenic stop variants in the ARD of NFKB2 can cause 'infection-only' CVID with an abnormal B-cell phenotype and a variable clinical penetrance.

11.
Br J Anaesth ; 123(1): e95-e103, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30955832

RESUMO

Chlorhexidine is an antiseptic with a broad spectrum of activity and a persistent effect on skin. Consequently, it has become an ubiquitous antiseptic in healthcare and the community. As use has become widespread, increasing numbers of cases of allergy have been reported in the literature, including cases of anaphylaxis to chlorhexidine gels used on mucous membranes, chlorhexidine-impregnated devices such as central venous catheters, chlorhexidine preparations used on wounds and broken skin, and cases after dental procedures. Numerous governmental warnings have been issued over recent decades to warn of the risk of allergy to chlorhexidine on mucosal surfaces or in medical devices. Whilst the number of published cases likely underestimates the true prevalence of reactions, we retrospectively surveyed clinics with experience in investigating perioperative chlorhexidine allergy. Despite differences in investigation practice before the survey took place, 13 clinics responded which together had diagnosed 252 cases of anaphylaxis to chlorhexidine, and cases of delayed allergy. In eight of 13 clinics, chlorhexidine was within the top four most commonly diagnosed causes of perioperative anaphylaxis. Despite this, the incidence of anaphylaxis to chlorhexidine is low given that patients are very commonly exposed. Sensitisation of healthcare workers can occur, but is uncommon. Before exposing patients to this antiseptic, consideration of the potential risk vs benefit should be undertaken, particularly for higher risk exposures, such as mucosal exposure or i.v. exposure via impregnated lines. Difficulties exist in protecting patients with known allergies from re-exposure to chlorhexidine, which would be improved with uniform labelling and chlorhexidine product registers.


Assuntos
Anti-Infecciosos Locais/efeitos adversos , Clorexidina/efeitos adversos , Hipersensibilidade a Drogas/diagnóstico , Hipersensibilidade a Drogas/terapia , Complicações Intraoperatórias/terapia , Complicações Pós-Operatórias/terapia , Humanos , Complicações Intraoperatórias/diagnóstico , Complicações Pós-Operatórias/diagnóstico
12.
Br J Anaesth ; 123(1): e126-e134, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31027914

RESUMO

Suspected perioperative allergic reactions are often severe. To avoid potentially life-threatening re-exposure to the culprit drug, establishing a firm diagnosis and identifying the culprit is crucial. Drug provocation tests are considered the gold standard in drug allergy investigation but have not been recommended in the investigation of perioperative allergy, mainly because of the pharmacological effects of drugs such as induction agents and neuromuscular blocking agents. Some specialised centres have reported benefits of provocation testing in perioperative allergy investigation, but the literature on the subject is limited. Here we provide a status update on the use of drug provocation testing in perioperative allergy, including its use in specific drug groups. This review is based on a literature search and experiences of the authors comprising anaesthesiologists and allergists with experience in perioperative allergy investigation. In addition, 19 participating centres in the International Suspected Perioperative Allergic Reaction Group were surveyed on the use of provocation testing in perioperative allergy investigation. A response was received from 13 centres in eight European countries, New Zealand, and the USA. Also, 21 centres from the Australian and New Zealand Anaesthetic Allergy Group were surveyed. Two centres performed provocation routinely and seven centres performed no provocations at all. Nearly half of the centres reported performing provocations with induction agents and neuromuscular blocking agents. Drug provocation testing is being used in perioperative allergy investigation in specialised centres, but collaborations between relevant specialties and multicentre studies are necessary to determine indications and establish common testing protocols.


Assuntos
Alérgenos/administração & dosagem , Hipersensibilidade a Drogas/diagnóstico , Técnicas In Vitro/métodos , Assistência Perioperatória/métodos , Testes Cutâneos/métodos , Humanos
14.
J Allergy Clin Immunol Pract ; 7(6): 1888-1893.e1, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30877074

RESUMO

BACKGROUND: Removal of an inaccurate penicillin allergy record following testing allows patients to access first-line treatment for infections, and reduce the use of broad-spectrum antibiotics, which contribute to antibiotic resistance. However, it is seldom undertaken. OBJECTIVES: To identify clinicians' working in primary care and patients' views on barriers and enablers for penicillin allergy testing and subsequent antibiotic use. METHODS: Fifty interviews with patients and clinicians, including 31 patients with a record of penicillin allergy, 16 with experience of testing, and 19 clinicians. Interviews were analyzed thematically. RESULTS: Patients were often unaware of the benefits of penicillin allergy testing and only those patients who had experienced negative consequences of having a penicillin allergy label were motivated to get tested. Clinicians were reluctant to change patient records on the basis of their clinical judgment alone but had limited experience of referring patients with suspected penicillin allergy and were often uncertain about referral criteria and what the testing involved. Clinicians felt that allergy testing could be beneficial and patients who had attended testing reported benefits of the test. Clinicians expressed uncertainty related to whose responsibility it was to make sure that the patient understood allergy test results. CONCLUSIONS: Clinicians would benefit from information about penicillin allergy testing to be able to use these services appropriately, and to discuss referral with patients. Patients might be more motivated to seek testing if they were more informed regarding its benefits. Good communication between primary and secondary care would facilitate the updating of medical records, and promote better patient education.

15.
Br J Anaesth ; 123(1): e16-e28, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30916015

RESUMO

Suspected perioperative hypersensitivity reactions are rare but contribute significantly to the morbidity and mortality of surgical procedures. Recent publications have highlighted the differences between countries concerning the respective risk of different drugs, and changes in patterns of causal agents and the emergence of new allergens. This review summarises recent information on the epidemiology of perioperative hypersensitivity reactions, with specific consideration of differences between geographic areas for the most frequently involved offending agents.


Assuntos
Anafilaxia/epidemiologia , Complicações Intraoperatórias/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Humanos
16.
BMJ Case Rep ; 12(1)2019 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-30612104

RESUMO

We report an interesting case of hepatitis C virus-negative type II cryoglobulinaemic vasculitis (CV) in a patient with a background history of systemic lupus erythematosus. The type II CV became less responsive to traditional treatments over time and culminated in an intensive care unit admission with critical multiorgan failure. A detailed flow cytometric evaluation of the bone marrow proved to be helpful in treatment. It demonstrated that bortezomib was a viable alternative treatment option for the type II CV. The patient received bortezomib and has made a full and durable recovery.


Assuntos
Bortezomib/uso terapêutico , Crioglobulinemia/tratamento farmacológico , Lúpus Eritematoso Sistêmico/complicações , Vasculite/tratamento farmacológico , Administração Intravenosa , Assistência ao Convalescente , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Medula Óssea/imunologia , Bortezomib/administração & dosagem , Crioglobulinemia/diagnóstico , Feminino , Citometria de Fluxo/métodos , Hepatite C/complicações , Humanos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/complicações , Resultado do Tratamento , Vasculite/diagnóstico , Vasculite/imunologia
17.
Nat Immunol ; 20(2): 152-162, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30643259

RESUMO

Stimulator of interferon genes (STING) is an endoplasmic reticulum (ER) signaling adaptor that is essential for the type I interferon response to DNA pathogens. Aberrant activation of STING is linked to the pathology of autoimmune and autoinflammatory diseases. The rate-limiting step for the activation of STING is its translocation from the ER to the ER-Golgi intermediate compartment. Here, we found that deficiency in the Ca2+ sensor stromal interaction molecule 1 (STIM1) caused spontaneous activation of STING and enhanced expression of type I interferons under resting conditions in mice and a patient with combined immunodeficiency. Mechanistically, STIM1 associated with STING to retain it in the ER membrane, and coexpression of full-length STIM1 or a STING-interacting fragment of STIM1 suppressed the function of dominant STING mutants that cause autoinflammatory diseases. Furthermore, deficiency in STIM1 strongly enhanced the expression of type I interferons after viral infection and prevented the lethality of infection with a DNA virus in vivo. This work delineates a STIM1-STING circuit that maintains the resting state of the STING pathway.


Assuntos
Interferon Tipo I/imunologia , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Animais , Cercopithecus aethiops , Pré-Escolar , DNA Viral/imunologia , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Fibroblastos , Técnicas de Inativação de Genes , Células HEK293 , Herpes Simples/imunologia , Herpes Simples/virologia , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/imunologia , Humanos , Imunidade Inata , Células Jurkat , Macrófagos , Masculino , Proteínas de Membrana/imunologia , Camundongos , Camundongos Knockout , Células NIH 3T3 , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Cultura Primária de Células , Imunodeficiência Combinada Severa/sangue , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/imunologia , Células Vero
18.
Blood ; 133(8): 820-829, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30538136

RESUMO

The Recombination Activating Genes, RAG1 and RAG2, are essential for V(D)J recombination and adaptive immunity. Mutations in these genes often cause immunodeficiency, the severity of which reflects the importance of the altered residue or residues during recombination. Here, we describe a novel RAG1 mutation that causes immunodeficiency in an unexpected way: The mutated protein severely disrupts binding of the accessory protein, HMGB1. Although HMGB1 enhances RAG cutting in vitro, its role in vivo was controversial. We show here that reduced HMGB1 binding by the mutant protein dramatically reduces RAG cutting in vitro and almost completely eliminates recombination in vivo. The RAG1 mutation, R401W, places a bulky tryptophan opposite the binding site for HMG Box A at both 12- and 23-spacer recombination signal sequences, disrupting stable binding of HMGB1. Replacement of R401W with leucine and then lysine progressively restores HMGB1 binding, correlating with increased RAG cutting and recombination in vivo. We show further that knockdown of HMGB1 significantly reduces recombination by wild-type RAG1, whereas its re-addition restores recombination with wild-type, but not the mutant, RAG1 protein. Together, these data provide compelling evidence that HMGB1 plays a critical role during V(D)J recombination in vivo.


Assuntos
Proteína HMGB1 , Proteína HMGB2 , Proteínas de Homeodomínio , Mutação de Sentido Incorreto , Recombinação V(D)J/imunologia , Substituição de Aminoácidos , Animais , Células HEK293 , Proteína HMGB1/genética , Proteína HMGB1/imunologia , Proteína HMGB2/genética , Proteína HMGB2/imunologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/imunologia , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Camundongos , Células NIH 3T3
19.
Artigo em Inglês | MEDLINE | ID: mdl-30170123

RESUMO

BACKGROUND: Caspase activation and recruitment domain 11 (CARD11) encodes a scaffold protein in lymphocytes that links antigen receptor engagement with downstream signaling to nuclear factor κB, c-Jun N-terminal kinase, and mechanistic target of rapamycin complex 1. Germline CARD11 mutations cause several distinct primary immune disorders in human subjects, including severe combined immune deficiency (biallelic null mutations), B-cell expansion with nuclear factor κB and T-cell anergy (heterozygous, gain-of-function mutations), and severe atopic disease (loss-of-function, heterozygous, dominant interfering mutations), which has focused attention on CARD11 mutations discovered by using whole-exome sequencing. OBJECTIVES: We sought to determine the molecular actions of an extended allelic series of CARD11 and to characterize the expanding range of clinical phenotypes associated with heterozygous CARD11 loss-of-function alleles. METHODS: Cell transfections and primary T-cell assays were used to evaluate signaling and function of CARD11 variants. RESULTS: Here we report on an expanded cohort of patients harboring novel heterozygous CARD11 mutations that extend beyond atopy to include other immunologic phenotypes not previously associated with CARD11 mutations. In addition to (and sometimes excluding) severe atopy, heterozygous missense and indel mutations in CARD11 presented with immunologic phenotypes similar to those observed in signal transducer and activator of transcription 3 loss of function, dedicator of cytokinesis 8 deficiency, common variable immunodeficiency, neutropenia, and immune dysregulation, polyendocrinopathy, enteropathy, X-linked-like syndrome. Pathogenic variants exhibited dominant negative activity and were largely confined to the CARD or coiled-coil domains of the CARD11 protein. CONCLUSION: These results illuminate a broader phenotypic spectrum associated with CARD11 mutations in human subjects and underscore the need for functional studies to demonstrate that rare gene variants encountered in expected and unexpected phenotypes must nonetheless be validated for pathogenic activity.

20.
Autoimmun Rev ; 17(11): 1115-1123, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30213700

RESUMO

The classical autoimmunity paradigm in rheumatoid arthritis (RA) is strongly supported by immunogenetics suggesting follicular helper T-cell responses driving high titre specific autoantibodies that pre-dates disease onset. Using the immunological disease continuum model of inflammation against self with "pure" adaptive and innate immune disease at opposite boundaries, we propose a novel immune mechanistic classification describing the heterogeneity within RA. Mutations or SNPs in autoinflammatory genes including MEFV and NOD2 are linked to seronegative RA phenotypes including some so called palindromic RA cases. However, just as innate and adaptive immunity are closely functionally integrated, some ACPA+ RA cases have superimposed "autoinflammatory" features including abrupt onset attacks, severe attacks, self-limiting attacks, relevant autoinflammatory mutations or SNPs and therapeutic responses to autoinflammatory pathway therapies including colchicine and IL-1 pathway blockade. An emergent feature from this classification that non-destructive RA phenotypes, both innate and adaptive, have disease epicentres situated in the extracapsular tissues. This mixed innate and adaptive immunopathogenesis may be the key to understanding severe disease flares, resistant disease subsets that are unresponsive to standard therapy and for therapies that target the autoinflammatory component of disease that are not currently considered by expert therapeutic recommendations.

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