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1.
J Clin Immunol ; 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33534079

RESUMO

Phosphoglucomutase 3 (PGM3) deficiency is a rare congenital disorder of glycosylation. Most of patients with autosomal recessive hypomorphic mutations in PGM3 encoding for phosphoglucomutase 3 present with eczema, skin and lung infections, elevated serum IgE, as well as neurological and skeletal features. A few PGM3-deficient patients suffer from a more severe disease with nearly absent T cells and severe skeletal dysplasia. We performed targeted next-generation sequencing on two kindred to identify the underlying genetic etiology of a severe combined immunodeficiency with developmental defect. We report here two novel homozygous missense variants (p.Gly359Asp and p.Met423Thr) in PGM3 identified in three patients from two unrelated kindreds with severe combined immunodeficiency, neurological impairment, and skeletal dysplasia. Both variants segregated with the disease in the two families. They were predicted to be deleterious by in silico analysis. PGM3 enzymatic activity was found to be severely impaired in primary fibroblasts and Epstein-Barr virus immortalized B cells from the kindred carrying the p.Met423Thr variant. Our findings support the pathogenicity of these two novel variants in severe PGM3 deficiency.

2.
J Exp Med ; 218(4)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33533916

RESUMO

Several studies have analyzed antiviral immune pathways in late-stage severe COVID-19. However, the initial steps of SARS-CoV-2 antiviral immunity are poorly understood. Here we have isolated primary SARS-CoV-2 viral strains and studied their interaction with human plasmacytoid predendritic cells (pDCs), a key player in antiviral immunity. We show that pDCs are not productively infected by SARS-CoV-2. However, they efficiently diversified into activated P1-, P2-, and P3-pDC effector subsets in response to viral stimulation. They expressed CD80, CD86, CCR7, and OX40 ligand at levels similar to influenza virus-induced activation. They rapidly produced high levels of interferon-α, interferon-λ1, IL-6, IP-10, and IL-8. All major aspects of SARS-CoV-2-induced pDC activation were inhibited by hydroxychloroquine. Mechanistically, SARS-CoV-2-induced pDC activation critically depended on IRAK4 and UNC93B1, as established using pDC from genetically deficient patients. Overall, our data indicate that human pDC are efficiently activated by SARS-CoV-2 particles and may thus contribute to type I IFN-dependent immunity against SARS-CoV-2 infection.


Assuntos
/imunologia , Plasticidade Celular/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , /imunologia , Biomarcadores , /virologia , Citocinas/metabolismo , Células Dendríticas/virologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Hidroxicloroquina/farmacologia , Hidroxicloroquina/uso terapêutico , Imunomodulação , Imunofenotipagem , Mediadores da Inflamação/metabolismo , Interferon Tipo I/metabolismo , Interferons/metabolismo
3.
J Clin Immunol ; 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33598806

RESUMO

The most recent updated classification of inborn errors of immunity/primary immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee, was published in January 2020. Within days of completing this report, it was already out of date, evidenced by the frequent publication of genetic variants proposed to cause novel inborn errors of immunity. As the next formal report from the IUIS Expert Committee will not be published until 2022, we felt it important to provide the community with a brief update of recent contributions to the field of inborn errors of immunity. Herein, we highlight studies that have identified 26 additional monogenic gene defects that reach the threshold to represent novel causes of immune defects.

4.
Haematologica ; 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33440924

RESUMO

Pediatric-onset Evans syndrome (pES) is defined by both immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AIHA) before the age of 18 years. There have been no comprehensive long-term studies of this rare disease, which can be associated to various immunopathological manifestations (IMs). We report outcomes of the 151 patients with pES and more than 5 years of follow-up from the nationwide French prospective OBS'CEREVANCE cohort. Median age at final follow-up was 18.5 (6.8-50.0) years and the median follow-up period was 11.3 (5.1-38.0) years. At 10 years, ITP and AIHA were in sustained complete remission in 54.5% and 78.4% of patients, respectively. The frequency and number of clinical and biological IMs increased with age: at 20 years old, 74% had at least one clinical cIM. A wide range of cIMs occurred, mainly lymphoproliferation, dermatological, gastrointestinal/hepatic and pneumological IMs. The number of cIMs was associated with a subsequent increase in the number of second-line treatments received (other than steroids and immunoglobulins; hazard ratio, 1.4; 95% confidence interval, 1.15-1.60; p = 0.0002, Cox proportional hazards method). Survival at 15 years after diagnosis was 84%. Death occurred at a median age of 18 (1.7-31.5) years, and the most frequent cause was infection. The number of second-line treatments and severe/recurrent infections were independently associated with mortality. In conclusion, longterm outcomes of pES showed remission of cytopenias but frequent IMs linked to high secondline treatment burden. Mortality was associated to drugs and/or underlying immunodeficiencies, and adolescents-young adults are a high-risk subgroup.

6.
J Clin Invest ; 2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33290277

RESUMO

Inborn errors of immunity cause monogenic immune dysregulatory conditions such as severe and recurrent pathogen infection, inflammation, allergy and malignancy. Somatic reversion refers to the spontaneous repair of a pathogenic germline genetic variant and has been reported to occur in a number of inborn errors of immunity with a range of impacts on clinical outcomes of these conditions. DOCK8 deficiency due to bi-allelic inactivating mutations in DOCK8 causes a combined immunodeficiency characterised by severe bacterial, viral and fungal infections, as well as allergic disease and some cancers. Here, we describe the clinical, genetic and cellular features of three patients with bi-allelic DOCK8 variants who, following somatic reversion in multiple lymphocyte subsets, exhibited improved clinical features, including complete resolution of infection and allergic disease, cure over time. Acquisition of DOCK8 expression restored defective lymphocyte signalling, survival and proliferation, as well as CD8+ T cell cytotoxicity, CD4+ T cell cytokine production, and memory B cell generation compared to typical DOCK8-deficient patients. Our temporal analysis of DOCK8-revertant and DOCK8-deficient cells within the same individual established mechanisms of clinical improvement in these patients following somatic reversion and revealed further non-redundant functions of DOCK8 in human lymphocyte biology. Lastly, our findings have significant implications for future therapeutic options for the treatment of DOCK8 deficiency.

7.
Nat Commun ; 11(1): 5341, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087723

RESUMO

Autoimmunity can occur when a checkpoint of self-tolerance fails. The study of familial autoimmune diseases can reveal pathophysiological mechanisms involved in more common autoimmune diseases. Here, by whole-exome/genome sequencing we identify heterozygous, autosomal-dominant, germline loss-of-function mutations in the SOCS1 gene in ten patients from five unrelated families with early onset autoimmune manifestations. The intracellular protein SOCS1 is known to downregulate cytokine signaling by inhibiting the JAK-STAT pathway. Accordingly, patient-derived lymphocytes exhibit increased STAT activation in vitro in response to interferon-γ, IL-2 and IL-4 that is reverted by the JAK1/JAK2 inhibitor ruxolitinib. This effect is associated with a series of in vitro and in vivo immune abnormalities consistent with lymphocyte hyperactivity. Hence, SOCS1 haploinsufficiency causes a dominantly inherited predisposition to early onset autoimmune diseases related to cytokine hypersensitivity of immune cells.


Assuntos
Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Autoimunidade/genética , Proteína 1 Supressora da Sinalização de Citocina/deficiência , Proteína 1 Supressora da Sinalização de Citocina/genética , Adolescente , Adulto , Idade de Início , Doenças Autoimunes/metabolismo , Criança , Pré-Escolar , Citocinas/metabolismo , Feminino , Haploinsuficiência , Humanos , Masculino , Modelos Moleculares , Mutação , Linhagem , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Proteína 1 Supressora da Sinalização de Citocina/química , Linfócitos T/imunologia
8.
J Clin Immunol ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33083971

RESUMO

IRAK4 deficiency is an inborn error of immunity predisposing patients to invasive pyogenic infections. Currently, there is no established simple assay that enables precise characterization of IRAK4 mutant alleles in isolation. Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune condition that is characterized by psychiatric symptoms, involuntary movement, seizures, autonomic dysfunction, and central hypoventilation. It typically occurs in adult females associated with tumors. Only a few infantile cases with anti-NMDAR encephalitis have been so far reported. We identified a 10-month-old boy with IRAK4 deficiency presenting with anti-NMDAR encephalitis and human herpes virus 6 (HHV6) reactivation. The diagnosis of IRAK4 deficiency was confirmed by the identification of compound heterozygous mutations c.29_30delAT (p.Y10Cfs*9) and c.35G>C (p.R12P) in the IRAK4 gene, low levels of IRAK4 protein expression in peripheral blood, and defective fibroblastic cell responses to TLR and IL-1 (TIR) agonist. We established a novel NF-κB reporter assay using IRAK4-null HEK293T, which enabled the precise evaluation of IRAK4 mutations. Using this system, we confirmed that both novel mutations identified in the patient are deleterious. Our study provides a new simple and reliable method to analyze IRAK4 mutant alleles. It also suggests the possible link between inborn errors of immunity and early onset anti-NMDAR encephalitis.

10.
J Exp Med ; 217(11)2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-32812031

RESUMO

Epstein-Barr virus (EBV) preferentially infects epithelial cells and B lymphocytes and sometimes T and NK lymphocytes. Persistence of EBV-infected cells results in severe lymphoproliferative disorders (LPDs). Diagnosis of EBV-driven T or NK cell LPD and chronic active EBV diseases (CAEBV) is difficult, often requiring biopsies. Herein, we report a flow-FISH cytometry assay that detects cells expressing EBV-encoded small RNAs (EBERs), allowing rapid identification of EBV-infected cells among PBMCs. EBV-infected B, T, and/or NK cells were detectable in various LPD conditions. Diagnosis of CAEBV in 22 patients of Caucasian and African origins was established. All exhibited circulating EBV-infected T and/or NK cells, highlighting that CAEBV is not restricted to native American and Asian populations. Proportions of EBV-infected cells correlated with blood EBV loads. We showed that EBV-infected T cells had an effector memory activated phenotype, whereas EBV-infected B cells expressed plasma cell differentiation markers. Thus, this method achieves accurate and unambiguous diagnoses of different forms of EBV-driven LPD and represents a powerful tool to study their pathophysiological mechanisms.

14.
JCI Insight ; 5(5)2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32161190

RESUMO

Cytidine triphosphate (CTP) synthetase 1 (CTPS1) deficiency is caused by a unique homozygous frameshift splice mutation (c.1692-1G>C, p.T566Dfs26X). CTPS1-deficient patients display severe bacterial and viral infections. CTPS1 is responsible for CTP nucleotide de novo production involved in DNA/RNA synthesis. Herein, we characterized in depth lymphocyte defects associated with CTPS1 deficiency. Immune phenotyping performed in 7 patients showed absence or low numbers of mucosal-associated T cells, invariant NKT cells, memory B cells, and NK cells, whereas other subsets were normal. Proliferation and IL-2 secretion by T cells in response to TCR activation were markedly decreased in all patients, while other T cell effector functions were preserved. The CTPS1T566Dfs26X mutant protein was found to be hypomorphic, resulting in 80%-90% reduction of protein expression and CTPS activity in cells of patients. Inactivation of CTPS1 in a T cell leukemia fully abolished cell proliferation. Expression of CTPS1T566Dfs26X failed to restore proliferation of CTPS1-deficient leukemia cells to normal, except when forcing its expression to a level comparable to that of WT CTPS1. This indicates that CTPS1T566Dfs26X retained normal CTPS activity, and thus the loss of function of CTPS1T566Dfs26X is completely attributable to protein instability. This study supports that CTPS1 represents an attractive therapeutic target to selectively inhibit pathological T cell proliferation, including lymphoma.

16.
17.
Front Immunol ; 11: 38, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32047500

RESUMO

In humans, loss-of-function mutation in the Signal Transducer and Activator of Transcription 3 (STAT3) gene is frequently associated with susceptibility to bacterial as well as fungal infections including aspergillosis, although its pathogenesis remains largely unknown. In the present study, we investigated the immune responses obtained after stimulation with Aspergillus fumigatus in STAT3-deficient patients. A. fumigatus conidial killing efficiencies of both monocytes and neutrophils isolated from whole blood samples of STAT3-deficient patients were not different compared to those of healthy controls. After stimulation with A. fumigatus conidia, lower concentrations of adaptive cytokines (IFN-γ, IL-17 and IL-22) were secreted by peripheral blood mononuclear cells from STAT3-deficient patients compared to those from healthy controls. Moreover, the frequency of IFN-γ and IL-17 producing CD4+ T cells was lower in STAT3-deficient patients vs. healthy controls. Among the STAT3-deficient patients, those with aspergillosis showed further lower secretion of IFN-γ upon stimulation of their PBMCs with A. fumigatus conidia compared to the patients without aspergillosis. Together, our study indicated that STAT3-deficiency leads to a defective adaptive immune response against A. fumigatus infection, particularly with a lower IFN-γ and IL-17 responses in those with aspergillosis, suggesting potential therapeutic benefit of recombinant IFN-γ in STAT3-deficient patients with aspergillosis.

18.
J Clin Immunol ; 40(1): 66-81, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32048120

RESUMO

Since 2013, the International Union of Immunological Societies (IUIS) expert committee (EC) on Inborn Errors of Immunity (IEI) has published an updated phenotypic classification of IEI, which accompanies and complements their genotypic classification into ten tables. This phenotypic classification is user-friendly and serves as a resource for clinicians at the bedside. There are now 430 single-gene IEI underlying phenotypes as diverse as infection, malignancy, allergy, autoimmunity, and autoinflammation. We herein report the 2019 phenotypic classification, including the 65 new conditions. The diagnostic algorithms are based on clinical and laboratory phenotypes for each of the ten broad categories of IEI.

19.
Haematologica ; 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919089

RESUMO

Severe combined immunodeficiencies (SCIDs) constitute a heterogeneous group of life-threatening genetic disorders that typically present in the first year of life. They are defined by the absence of autologous T cells and the presence of an intrinsic or extrinsic defect in the B-cell compartment. In three newborns presenting with frequent infections and profound leukopenia, we identified a private, heterozygous mutation in the RAC2 gene (p.G12R). This mutation was de novo in the index case, who had been cured by hematopoietic stem cell transplantation but had transmitted the mutation to her sick daughter. Biochemical assays showed that the mutation was associated with a gain of function. The results of in vitro differentiation assays showed that RAC2 is essential for the survival and differentiation of hematopoietic stem/progenitor cells. Therefore, screening for RAC2 gain-of-function mutations should be considered in patients with a SCID phenotype and who lack a molecular diagnosis.

20.
J Clin Immunol ; 40(1): 24-64, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31953710

RESUMO

We report the updated classification of Inborn Errors of Immunity/Primary Immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 430 inborn errors of immunity, including 64 gene defects that have either been discovered in the past 2 years since the previous update (published January 2018) or were characterized earlier but have since been confirmed or expanded upon in subsequent studies. The application of next-generation sequencing continues to expedite the rapid identification of novel gene defects, rare or common; broaden the immunological and clinical phenotypes of conditions arising from known gene defects and even known variants; and implement gene-specific therapies. These advances are contributing to greater understanding of the molecular, cellular, and immunological mechanisms of disease, thereby enhancing immunological knowledge while improving the management of patients and their families. This report serves as a valuable resource for the molecular diagnosis of individuals with heritable immunological disorders and also for the scientific dissection of cellular and molecular mechanisms underlying inborn errors of immunity and related human diseases.

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