Genetic susceptibility to aspergillosis in allogeneic stem-cell transplantation

Invasive aspergillosis (IA) is a major threat to positive outcomes for allogeneic stem-cell transplantation (allo-SCT) patients. Despite presenting similar degrees of immunosuppression, not all individuals at-risk ultimately develop infection. Therefore, the traditional view of neutropenia as a key risk factor for aspergillosis needs to be accommodated within new conceptual advances on host immunity and its relationship to infection. Polymorphisms in innate immune genes, such as those encoding TLRs, cytokines and cytokine receptors, have recently been associated with susceptibility to IA in allo-SCT recipients. This suggests that understanding host-pathogen interactions at the level of host genetic susceptibility will allow the formulation of new targeted and patient-tailored antifungal therapeutics, including improved donor screening.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/65962/2009, SFRH/BPD/46292/2008Specific Targeted Research Projects MANASP (LSHE-CT-2006), contract number 037899 (FP6), Italian Project PRIN2007KLCKP8_004

The IL-17F/IL-17RC Axis Promotes Respiratory Allergy in the Proximal Airways

Summary The interleukin 17 (IL-17) cytokine and receptor family is central to antimicrobial resistance and inflammation in the lung. Mice lacking IL-17A, IL-17F, or the IL-17RA subunit were compared with wild-type mice for susceptibility to airway inflammation in models of infection and allergy. Signaling through IL-17RA was required for efficient microbial clearance and prevention of allergy; in the absence of IL-17RA, signaling through IL-17RC on epithelial cells, predominantly by IL-17F, significantly exacerbated lower airway Aspergillus or Pseudomonas infection and allergic airway inflammation. In contrast, following infection with the upper respiratory pathogen Staphylococcus aureus , the IL-17F/IL-17RC axis mediated protection. Thus, IL-17A and IL-17F exert distinct biological effects during pulmonary infection; the IL-17F/IL-17RC signaling axis has the potential to significantly worsen pathogen-associated inflammation of the lower respiratory tract in particular, and should be investigated further as a therapeutic target for treating pathological inflammation in the lung

A novel microdeletion syndrome at 3q13.31 characterised by developmental delay, postnatal overgrowth, hypoplastic male genitals, and characteristic facial features

Item does not contain fulltextBACKGROUND: Congenital deletions affecting 3q11q23 have rarely been reported and only five cases have been molecularly characterised. Genotype-phenotype correlation has been hampered by the variable sizes and breakpoints of the deletions. In this study, 14 novel patients with deletions in 3q11q23 were investigated and compared with 13 previously reported patients. METHODS: Clinical data were collected from 14 novel patients that had been investigated by high resolution microarray techniques. Molecular investigation and updated clinical information of one cytogenetically previously reported patient were also included. RESULTS: The molecular investigation identified deletions in the region 3q12.3q21.3 with different boundaries and variable sizes. The smallest studied deletion was 580 kb, located in 3q13.31. Genotype-phenotype comparison in 24 patients sharing this shortest region of overlapping deletion revealed several common major characteristics including significant developmental delay, muscular hypotonia, a high arched palate, and recognisable facial features including a short philtrum and protruding lips. Abnormal genitalia were found in the majority of males, several having micropenis. Finally, a postnatal growth pattern above the mean was apparent. The 580 kb deleted region includes five RefSeq genes and two of them are strong candidate genes for the developmental delay: DRD3 and ZBTB20. CONCLUSION: A newly recognised 3q13.31 microdeletion syndrome is delineated which is of diagnostic and prognostic value. Furthermore, two genes are suggested to be responsible for the main phenotype.1 februari 201

Mutation spectrum of MLL2 in a cohort of kabuki syndrome patients

ABSTRACT: BACKGROUND: Kabuki syndrome (Niikawa-Kuroki syndrome) is a rare, multiple congenital anomalies/mental retardation syndrome characterized by a peculiar face, short stature, skeletal, visceral and dermatoglyphic abnormalities, cardiac anomalies, and immunological defects. Recently mutations in the histone methyl transferase MLL2 gene have been identified as its underlying cause. METHODS: Genomic DNAs were extracted from 62 index patients clinically diagnosed as affected by Kabuki syndrome. Sanger sequencing was performed to analyze the whole coding region of the MLL2 gene including intron-exon junctions. The putative causal and possible functional effect of each nucleotide variant identified was estimated by in silico prediction tools. RESULTS: We identified 45 patients with MLL2 nucleotide variants. 38 out of the 42 variants were never described before. Consistently with previous reports, the majority are nonsense or frameshift mutations predicted to generate a truncated polypeptide. We also identified 3 indel, 7 missense and 3 splice site. CONCLUSIONS: This study emphasizes the relevance of mutational screening of the MLL2 gene among patients diagnosed with Kabuki syndrome. The identification of a large spectrum of MLL2 mutations possibly offers the opportunity to improve the actual knowledge on the clinical basis of this multiple congenital anomalies/mental retardation syndrome, design functional studies to understand the molecular mechanisms underlying this disease, establish genotype-phenotype correlations and improve clinical management

Genetic deficiency of NOD2 confers resistance to invasive aspergillosis

Invasive aspergillosis (IA) is a severe infection that can occur in severely immunocompromised patients. Efficient immune recognition of Aspergillus is crucial to protect against infection, and previous studies suggested a role for NOD2 in this process. However, thorough investigation of the impact of NOD2 on susceptibility to aspergillosis is lacking. Common genetic variations in NOD2 has been associated with Crohn's disease and here we investigated the influence of these  genetic variations on the anti-Aspergillus host response. A NOD2 polymorphism reduced the risk of IA after hematopoietic stem-cell transplantation. Mechanistically, absence of NOD2 in monocytes and macrophages increases phagocytosis leading to enhanced fungal killing, conversely, NOD2 activation reduces the antifungal potential of these cells. Crucially, Nod2 deficiency results in resistance to Aspergillus infection in an in vivo model of pulmonary aspergillosis. Collectively, our data demonstrate that genetic deficiency of NOD2 plays a protective role during Aspergillus infection.We thank C. Wertz and M. Fanton D'Andon for providing Nod2-deficient mice, M. Schlotter for organizing patient inclusion, B. Rosler for assistance with flowcytometry. We also thank the NOD2-deficient patients for contributing to our study by providing blood samples. M.S.G. was supported by the Erasmus lifelong learning program. F.L.v.d.V. was supported by the E-rare project EURO-CMC. M.O. was supported by the NWO, 016.176.006). A.C. and C.C. were supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundacao para a Ciencia e Tecnologia (FCT) (IF/00735/2014 to A.C. and SFRH/BPD/96176/2013 to C. C.)

Non-hematopoietic cells contribute to protective tolerance to Aspergillus fumigatus via a TRIF pathway converging on IDO

Innate responses combine with adaptive immunity to generate the most effective form of anti-Aspergillus immune resistance. Whereas the pivotal role of dendritic cells in determining the balance between immunopathology and protective immunity to the fungus is well established, we determined that epithelial cells (ECs) also contributes to this balance. Mechanistically, EC-mediated protection occurred through a Toll-like receptor 3/Toll/IL-1 receptor domain-containing adaptor-inducing interferon (TLR3/TRIF)-dependent pathway converging on indoleamine 2,3-dioxygenase (IDO) via non-canonical nuclear factor-?B activation. Consistent with the high susceptibility of TRIF-deficient mice to pulmonary aspergillosis, bone marrow chimeric mice with TRIF unresponsive ECs exhibited higher fungal burdens and inflammatory pathology than control mice, underexpressed the IDO-dependent T helper 1/regulatory T cell (Th1/Treg) pathway and overexpressed the Th17 pathway with massive neutrophilic inflammation in the lungs. Further studies with interferon (IFN)-?, IDO or IL-17R unresponsive cells confirmed the dependency of immune tolerance to the fungus on the IFN-?/IDO/Treg pathway and of immune resistance on the MyD88 pathway controlling the fungal growth. Thus, distinct immune pathways contribute to resistance and tolerance to the fungus, to which the hematopoietic/non-hematopoietic compartments contribute through distinct, yet complementary, roles.We thank Cristina Massi Benedetti for digital art and editing. This work was supported by the Specific Targeted Research Project 'Sybaris' (LSHE-CT-2006), contract number 037899 (FP7) and by the Italian Projects PRIN 2007KLCKP8_004 (to LR) and 2007XYB9T9_001 (to SB). CC and AC were financially supported by fellowships from Fundacao para a Ciencia e Tecnologia, Portugal (contracts SFRH/BD/65962/2009 and SFRH/BPD/46292/2008, respectively)

Dectin-1 isoforms contribute to distinct Th1/Th17 cell activation in mucosal candidiasis

We thank Dr. Cristina Massi Benedetti for digital art and editingRecognition of β-glucans by dectin-1 has been shown to mediate cell activation, cytokine production and a variety of antifungal responses. Here, we report that the functional activity of dectin-1 in mucosal immunity to Candida albicans is influenced by the genetic background of the host. Dectin-1 was required for the proper control of gastrointestinal and vaginal candidiasis in C57BL/6 but not BALB/c mice, the latter actually showing increased resistance in the absence of dectin-1. Susceptibility of dectin-1-deficient C57BL/6 mice to infection was associated with defective IL-17A, aryl hydrocarbon receptor-dependent IL-22 production as well as adaptive Th1 responses. In contrast, resistance of dectin-1-deficient BALB/c mice was associated with increased IL-17A and IL-22 production, and the skewing towards Th1/Treg immune responses that provide immunological memory. Disparate canonical/noncanonical NF-κB signaling pathways downstream dectin-1were activated in the two different mouse strains. Thus, the net activity of dectin-1 in antifungal mucosal immunity is dependent on the host’s genetic background that affects both the innate cytokine production as well as the adaptive Th1/Th17 cell activation upon dectin-1 signaling.The studies were supported by the Specific Targeted Research Project “ALLFUN” (FP7−HEALTH−2009 contract number 260338 to LR) and the Italian Project AIDS 2010 by ISS (Istituto Superiore di Sanità - contract number 40H40 to LR) and Fondazione Cassa di Risparmio di Perugia Project n. 2011.0124.021. AC and CC were financially supported by fellowships from Fundação para a Ciência e Tecnologia, Portugal (contracts SFRH/BPD/46292/2008 and SFRH/BD/65962/2009, respectively)

A comprehensive introduction to the genetic basis of non-syndromic hearing loss in the Saudi Arabian population

<p>Abstract</p> <p>Background</p> <p>Hearing loss is a clinically and genetically heterogeneous disorder. Mutations in the <it>DFNB1 </it>locus have been reported to be the most common cause of autosomal recessive non-syndromic hearing loss worldwide. Apart from <it>DFNB1</it>, many other loci and their underlying genes have also been identified and the basis of our study was to provide a comprehensive introduction to the delineation of the molecular basis of non-syndromic hearing loss in the Saudi Arabian population. This was performed by screening <it>DFNB1 </it>and to initiate prioritized linkage analysis or homozygosity mapping for a pilot number of families in which <it>DFNB1 </it>has been excluded.</p> <p>Methods</p> <p>Individuals from 130 families of Saudi Arabian tribal origin diagnosed with an autosomal recessive non-syndromic sensorineural hearing loss were screened for mutations at the <it>DFNB1 </it>locus by direct sequencing. If negative, genome wide linkage analysis or homozygosity mapping were performed using Affymetrix GeneChip^®Human Mapping 250K/6.0 Arrays to identify regions containing any known-deafness causing genes that were subsequently sequenced.</p> <p>Results</p> <p>Our results strongly indicate that <it>DFNB1 </it>only accounts for 3% of non-syndromic hearing loss in the Saudi Arabian population of ethnic ancestry. Prioritized linkage analysis or homozygosity mapping in five separate families established that their hearing loss was caused by five different known-deafness causing genes thus confirming the genetic heterogeneity of this disorder in the kingdom.</p> <p>Conclusion</p> <p>The overall results of this study are highly suggestive that underlying molecular basis of autosomal recessive non-syndromic deafness in Saudi Arabia is very genetically heterogeneous. In addition, we report that the preliminary results indicate that there does not seem to be any common or more prevalent loci, genes or mutations in patients with autosomal recessive non-syndromic hearing loss in patients of Saudi Arabian tribal origin.</p