21 research outputs found

    Mutations affecting the actin regulator WD repeat–containing protein 1 lead to aberrant lymphoid immunity

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    Background: The actin-interacting protein WD repeat–containing protein 1 (WDR1) promotes cofilin-dependent actin filament turnover. Biallelic WDR1 mutations have been identified recently in an immunodeficiency/autoinflammatory syndrome with aberrant morphology and function of myeloid cells. Objective: Given the pleiotropic expression of WDR1, here we investigated to what extent it might control the lymphoid arm of the immune system in human subjects. Methods: Histologic and detailed immunologic analyses were performed to elucidate the role of WDR1 in the development and function of B and T lymphocytes. Results: Here we identified novel homozygous and compound heterozygous WDR1 missense mutations in 6 patients belonging to 3 kindreds who presented with respiratory tract infections, skin ulceration, and stomatitis. In addition to defective adhesion and motility of neutrophils and monocytes, WDR1 deficiency was associated with aberrant T-cell activation and B-cell development. T lymphocytes appeared to develop normally in the patients, except for the follicular helper T-cell subset. However, peripheral T cells from the patients accumulated atypical actin structures at the immunologic synapse and displayed reduced calcium flux and mildly impaired proliferation on T-cell receptor stimulation. WDR1 deficiency was associated with even more severe abnormalities of the B-cell compartment, including peripheral B-cell lymphopenia, paucity of B-cell progenitors in the bone marrow, lack of switched memory B cells, reduced clonal diversity, abnormal B-cell spreading, and increased apoptosis on B-cell receptor/Toll-like receptor stimulation. Conclusion: Our study identifies a novel role for WDR1 in adaptive immunity, highlighting WDR1 as a central regulator of actin turnover during formation of the B-cell and T-cell immunologic synapses

    A recessive form of hyper-IgE syndrome by disruption of ZNF341-dependent STAT3 transcription and activity.

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    Heterozygosity for human () dominant-negative (DN) mutations underlies an autosomal dominant form of hyper-immunoglobulin E syndrome (HIES). We describe patients with an autosomal recessive form of HIES due to loss-of-function mutations of a previously uncharacterized gene, ZNF341 is a transcription factor that resides in the nucleus, where it binds a specific DNA motif present in various genes, including the promoter. The patients\u27 cells have low basal levels of STAT3 mRNA and protein. The autoinduction of STAT3 production, activation, and function by STAT3-activating cytokines is strongly impaired. Like patients with DN mutations, ZNF341-deficient patients lack T helper 17 (T17) cells, have an excess of T2 cells, and have low memory B cells due to the tight dependence of STAT3 activity on ZNF341 in lymphocytes. Their milder extra-hematopoietic manifestations and stronger inflammatory responses reflect the lower ZNF341 dependence of STAT3 activity in other cell types. Human ZNF341 is essential for the transcription-dependent autoinduction and sustained activity of STAT3

    Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome

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    Autosomal dominant hyper-IgE syndrome (AD-HIES) is typically caused by dominant-negative (DN) STAT3 mutations. Patients suffer from cold staphylococcal lesions and mucocutaneous candidiasis, severe allergy, and skeletal abnormalities. We report 12 patients from 8 unrelated kindreds with AD-HIES due to DN IL6ST mutations. We identified seven different truncating mutations, one of which was recurrent. The mutant alleles encode GP130 receptors bearing the transmembrane domain but lacking both the recycling motif and all four STAT3-recruiting tyrosine residues. Upon overexpression, the mutant proteins accumulate at the cell surface and are loss of function and DN for cellular responses to IL-6, IL-11, LIF, and OSM. Moreover, the patients’ heterozygous leukocytes and fibroblasts respond poorly to IL-6 and IL-11. Consistently, patients with STAT3 and IL6ST mutations display infectious and allergic manifestations of IL-6R deficiency, and some of the skeletal abnormalities of IL-11R deficiency. DN STAT3 and IL6ST mutations thus appear to underlie clinical phenocopies through impairment of the IL-6 and IL-11 response pathways

    Comprehensive analysis of the cytokine-rich chromosome 5q31.1 region suggests a role for IL-4 gene variants in prostate cancer risk

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    Although inflammation is emerging as a candidate prostate cancer risk factor, the T-helper cytokine-rich [interleukins (IL)-5, 13 and 4] chromosomal region at 5q31.1 has been implicated in prostate cancer pathogenesis. In particular, IL-4 has been associated with prostate cancer progression, whereas the IL-4 -589C>T (rs2243250) promoter variant has been associated with differential gene expression. We genotyped rs2243250 and 11 tag single-nucleotide polymorphisms (SNPs) spanning 200 kb across the 5q31.1 region on 825 cases and 732 controls from the Risk Factors for Prostate Cancer Study. The minor alleles of rs2243250 and an IL-4 tagSNP rs2227284 were associated with a small increase in prostate cancer risk. Per allele odds ratios (ORs) are 1.32 [95% confidence interval (CI) 1.08-1.61, P = 0.006] and 1.26 (95% CI 1.07-1.48, P = 0.005), respectively. Although these associations were not replicated in an analysis of the Melbourne Collaborative Cohort Study, including 810 cases and 1733 controls, no clinicopathological characteristic was implicated for this divergence. Correlating rs2243250 genotypes to IL-4 gene transcript levels and circulating IL-4 plasma levels, we observe in contrast to previous reports, a non-significant trend toward the minor T-allele decreasing the likelihood of IL-4 activity. From our observed association between a low IL-4 producing promoter T-allele and prostate cancer risk, our study suggests an antitumor role for IL-4 in prostate cancer. Although we saw no association for IL-5 or IL-13 gene variants and prostate cancer risk, our findings call for further evaluation of IL-4 as a contributor to prostate cancer susceptibility. © The Author 2010. Published by Oxford University Press. All rights reserved.Articl

    A novel targeted amplicon Next-Generation sequencing gene panel for the diagnosis of common variable immunodeficiency has a high diagnostic yield

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    With the advent of next-generation sequencing (NGS), monogenic forms of common variable immunodeficiency (CVID) have been increasingly described. Our study aimed to identify disease-causing variants in a Western Australian CVID cohort using a novel targeted NGS panel. Targeted amplicon NGS was performed on 22 unrelated subjects who met the formal European Society for Immunodeficiencies–Pan-American Group for Immunodeficiency diagnostic criteria for CVID and had at least one of the following additional criteria: disease onset at age <18 years, autoimmunity, low memory B lymphocytes, family history, and/or history of lymphoproliferation. Candidate variants were assessed by in silico predictions of deleteriousness, comparison to the literature, and classified according to the American College of Medical Genetics and Genomics–Association for Molecular Pathology criteria. All detected genetic variants were verified independently by an external laboratory, and additional functional studies were performed if required. Pathogenic or likely pathogenic variants were detected in 6 of 22 (27%) patients. Monoallelic variants of uncertain significance were also identified in a further 4 of 22 patients (18%). Pathogenic variants, likely pathogenic variants, or variants of uncertain significance were found in TNFRSF13B, TNFRSF13C, ICOS, AICDA, IL21R, NFKB2, and CD40LG, including novel variants and variants with unexpected inheritance pattern. Targeted amplicon NGS is an effective tool to identify monogenic disease-causing variants in CVID, and is comparable or superior to other NGS methods. Moreover, targeted amplicon NGS identified patients who may benefit from targeted therapeutic strategies and had important implications for family members

    The immune response to primary EBV infection: a role for natural killer cells

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    The role of antigen-specific CD3&lt;sup&gt;+&lt;/sup&gt;CD8&lt;sup&gt;+&lt;/sup&gt; cytotoxic T cells in the control of primary Epstein–Barr Virus (EBV) infection is well established. However, time is required for the antigen-specific immune response to develop and expand. In contrast, innate immune responses, such as natural killer (NK) cells, are considered vital early in the infection process. We analysed the scale, phenotype and function of the NK cell response during symptomatic primary EBV infection, infectious mononucleosis (IM) and showed that NK cell numbers were significantly elevated both at diagnosis of IM and in the first month following diagnosis. There were also significant changes in cell phenotype and function, an increase in the proportion of CD56&lt;sup&gt;bright&lt;/sup&gt; cells at diagnosis, and freshly isolated cells showing an enhanced ability to kill EBV-infected cell lines. Moreover, in our cohort of IM patients higher NK cell counts were associated with significantly lower viral load in peripheral blood. Our results suggest NK cells have an important role in the control of primary EBV infection by eliminating infected B cells and augmenting the antigen-specific T cell response via release of immunomodulatory cytokines. The magnitude of the NK cell response may ultimately determine whether primary EBV infection has a clinical outcome
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