Publications by authors named "Nico Marr"

39 Publications

Dromedary camels as a natural source of neutralizing nanobodies against SARS-CoV-2.

JCI Insight 2021 03 8;6(5). Epub 2021 Mar 8.

Genetic Intelligence Laboratory, Weill Cornell Medicine-Qatar, Qatar Foundation, Doha, Qatar.

The development of prophylactic and therapeutic agents for coronavirus disease 2019 (COVID-19) is a current global health priority. Here, we investigated the presence of cross-neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dromedary camels that were Middle East respiratory syndrome coronavirus (MERS-CoV) seropositive but MERS-CoV free. The tested 229 dromedaries had anti-MERS-CoV camel antibodies with variable cross-reactivity patterns against SARS-CoV-2 proteins, including the S trimer and M, N, and E proteins. Using SARS-CoV-2 competitive immunofluorescence immunoassays and pseudovirus neutralization assays, we found medium-to-high titers of cross-neutralizing antibodies against SARS-CoV-2 in these animals. Through linear B cell epitope mapping using phage immunoprecipitation sequencing and a SARS-CoV-2 peptide/proteome microarray, we identified a large repertoire of Betacoronavirus cross-reactive antibody specificities in these dromedaries and demonstrated that the SARS-CoV-2-specific VHH antibody repertoire is qualitatively diverse. This analysis revealed not only several SARS-CoV-2 epitopes that are highly immunogenic in humans, including a neutralizing epitope, but also epitopes exclusively targeted by camel antibodies. The identified SARS-CoV-2 cross-neutralizing camel antibodies are not proposed as a potential treatment for COVID-19. Rather, their presence in nonimmunized camels supports the development of SARS-CoV-2 hyperimmune camels, which could be a prominent source of therapeutic agents for the prevention and treatment of COVID-19.
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http://dx.doi.org/10.1172/jci.insight.145785DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8021111PMC
March 2021

Virome-wide serological profiling reveals association of herpesviruses with obesity.

Sci Rep 2021 Jan 28;11(1):2562. Epub 2021 Jan 28.

Research Branch, Sidra Medicine, Doha, Qatar.

The relationship between viral infection and obesity has been known for several decades but epidemiological data is limited to only a few viral pathogens. The association between obesity and a wide range of viruses was assessed using VirScan, a pan-viral serological profiling tool. Serum specimens from 457 Qatari adults (lean = 184; obese = 273) and 231 Qatari children (lean = 111; obese = 120) were analyzed by VirScan. Associations with obesity were determined by odds ratio (OR) and Fisher's test (p values), and by multivariate regression analysis to adjust for age and gender. Although there was no association of viral infections with obesity in the pediatric population, a nominal association of obesity with seropositivity to members of the Herpesviridae family is observed for the adult population (OR = 1.5-3.3; p < 0.05). After adjusting p values for multiple comparisons (Bonferroni correction) the odds of being obese is significantly higher in herpes simplex virus 1 (HSV-1) seropositive Qatari adults (OR = 3.3; 95% CI 2.15-4.99; p = 2.787E - 08). By VirScan, the sero-prevalence of HSV1 is 81.3% and 57.1% among Qatari obese and lean adult populations, respectively. Higher prevalence of antibodies against several peptide epitopes of HSV-1/2 is positively associated with obesity (OR = 2.35-3.82; p ≤ 3.981E - 05). By multivariate regression analysis, HSV-1 was independently associated with obesity irrespective of age and gender. Our results suggest that obesity among Qataris may be associated with a higher prevalence of herpesvirus infections, in particular HSV-1. Furthermore, the high prevalence of antibodies against peptide antigens specific to HSV-1 and -2 in the obese population suggests that these viral peptides may play a role in adipogenesis. Further studies with these candidate peptides in cell culture or animal models may confirm their adipogenic roles.
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http://dx.doi.org/10.1038/s41598-021-82213-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7843976PMC
January 2021

Distinct antibody repertoires against endemic human coronaviruses in children and adults.

JCI Insight 2021 02 22;6(4). Epub 2021 Feb 22.

Research Branch, Sidra Medicine, Doha, Qatar.

Four endemic human coronaviruses (HCoVs) are commonly associated with acute respiratory infection in humans. B cell responses to these "common cold" viruses remain incompletely understood. Here we report a comprehensive analysis of CoV-specific antibody repertoires in 231 children and 1168 adults using phage immunoprecipitation sequencing. Seroprevalence of antibodies against endemic HCoVs ranged between approximately 4% and 27% depending on the species and cohort. We identified at least 136 novel linear B cell epitopes. Antibody repertoires against endemic HCoVs were qualitatively different between children and adults in that anti-HCoV IgG specificities more frequently found among children targeted functionally important and structurally conserved regions of the spike, nucleocapsid, and matrix proteins. Moreover, antibody specificities targeting the highly conserved fusion peptide region and S2' cleavage site of the spike protein were broadly cross-reactive with peptides of epidemic human and nonhuman coronaviruses. In contrast, an acidic tandem repeat in the N-terminal region of the Nsp3 subdomain of the HCoV-HKU1 polyprotein was the predominant target of antibody responses in adult donors. Our findings shed light on the dominant species-specific and pan-CoV target sites of human antibody responses to coronavirus infection, thereby providing important insights for the development of prophylactic or therapeutic monoclonal antibodies and vaccine design.
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http://dx.doi.org/10.1172/jci.insight.144499DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7934927PMC
February 2021

Human T-bet Governs Innate and Innate-like Adaptive IFN-γ Immunity against Mycobacteria.

Cell 2020 Dec 8;183(7):1826-1847.e31. Epub 2020 Dec 8.

St Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, Rockefeller University, New York, NY 10065, USA; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, 75015 Paris, France; University of Paris, Imagine Institute, 75015 Paris, France; Pediatric Hematology-Immunology Unit, Necker Hospital for Sick Children, AP-HP, 75015 Paris, France; Howard Hughes Medical Institute, New York, NY, USA. Electronic address:

Inborn errors of human interferon gamma (IFN-γ) immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to inherited deficiency of the transcription factor T-bet. The patient has extremely low counts of circulating Mycobacterium-reactive natural killer (NK), invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and Vδ2 γδ T lymphocytes, and of Mycobacterium-non reactive classic T1 lymphocytes, with the residual populations of these cells also producing abnormally small amounts of IFN-γ. Other lymphocyte subsets develop normally but produce low levels of IFN-γ, with the exception of CD8 αβ T and non-classic CD4 αβ T1 lymphocytes, which produce IFN-γ normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and Vδ2 γδ T cells) and IFN-γ production by them, with mycobacterium-specific, IFN-γ-producing, purely adaptive CD8 αβ T, and CD4 αβ T1 cells unable to compensate for this deficit.
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http://dx.doi.org/10.1016/j.cell.2020.10.046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7770098PMC
December 2020

Inborn errors of type I IFN immunity in patients with life-threatening COVID-19.

Authors:
Qian Zhang Paul Bastard Zhiyong Liu Jérémie Le Pen Marcela Moncada-Velez Jie Chen Masato Ogishi Ira K D Sabli Stephanie Hodeib Cecilia Korol Jérémie Rosain Kaya Bilguvar Junqiang Ye Alexandre Bolze Benedetta Bigio Rui Yang Andrés Augusto Arias Qinhua Zhou Yu Zhang Fanny Onodi Sarantis Korniotis Léa Karpf Quentin Philippot Marwa Chbihi Lucie Bonnet-Madin Karim Dorgham Nikaïa Smith William M Schneider Brandon S Razooky Hans-Heinrich Hoffmann Eleftherios Michailidis Leen Moens Ji Eun Han Lazaro Lorenzo Lucy Bizien Philip Meade Anna-Lena Neehus Aileen Camille Ugurbil Aurélien Corneau Gaspard Kerner Peng Zhang Franck Rapaport Yoann Seeleuthner Jeremy Manry Cecile Masson Yohann Schmitt Agatha Schlüter Tom Le Voyer Taushif Khan Juan Li Jacques Fellay Lucie Roussel Mohammad Shahrooei Mohammed F Alosaimi Davood Mansouri Haya Al-Saud Fahd Al-Mulla Feras Almourfi Saleh Zaid Al-Muhsen Fahad Alsohime Saeed Al Turki Rana Hasanato Diederik van de Beek Andrea Biondi Laura Rachele Bettini Mariella D'Angio' Paolo Bonfanti Luisa Imberti Alessandra Sottini Simone Paghera Eugenia Quiros-Roldan Camillo Rossi Andrew J Oler Miranda F Tompkins Camille Alba Isabelle Vandernoot Jean-Christophe Goffard Guillaume Smits Isabelle Migeotte Filomeen Haerynck Pere Soler-Palacin Andrea Martin-Nalda Roger Colobran Pierre-Emmanuel Morange Sevgi Keles Fatma Çölkesen Tayfun Ozcelik Kadriye Kart Yasar Sevtap Senoglu Şemsi Nur Karabela Carlos Rodríguez-Gallego Giuseppe Novelli Sami Hraiech Yacine Tandjaoui-Lambiotte Xavier Duval Cédric Laouénan Andrew L Snow Clifton L Dalgard Joshua D Milner Donald C Vinh Trine H Mogensen Nico Marr András N Spaan Bertrand Boisson Stéphanie Boisson-Dupuis Jacinta Bustamante Anne Puel Michael J Ciancanelli Isabelle Meyts Tom Maniatis Vassili Soumelis Ali Amara Michel Nussenzweig Adolfo García-Sastre Florian Krammer Aurora Pujol Darragh Duffy Richard P Lifton Shen-Ying Zhang Guy Gorochov Vivien Béziat Emmanuelle Jouanguy Vanessa Sancho-Shimizu Charles M Rice Laurent Abel Luigi D Notarangelo Aurélie Cobat Helen C Su Jean-Laurent Casanova

Science 2020 10 24;370(6515). Epub 2020 Sep 24.

St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, USA.

Clinical outcome upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from silent infection to lethal coronavirus disease 2019 (COVID-19). We have found an enrichment in rare variants predicted to be loss-of-function (LOF) at the 13 human loci known to govern Toll-like receptor 3 (TLR3)- and interferon regulatory factor 7 (IRF7)-dependent type I interferon (IFN) immunity to influenza virus in 659 patients with life-threatening COVID-19 pneumonia relative to 534 subjects with asymptomatic or benign infection. By testing these and other rare variants at these 13 loci, we experimentally defined LOF variants underlying autosomal-recessive or autosomal-dominant deficiencies in 23 patients (3.5%) 17 to 77 years of age. We show that human fibroblasts with mutations affecting this circuit are vulnerable to SARS-CoV-2. Inborn errors of TLR3- and IRF7-dependent type I IFN immunity can underlie life-threatening COVID-19 pneumonia in patients with no prior severe infection.
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http://dx.doi.org/10.1126/science.abd4570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7857407PMC
October 2020

Herpes simplex encephalitis in a patient with a distinctive form of inherited IFNAR1 deficiency.

J Clin Invest 2021 Jan;131(1)

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France.

Inborn errors of TLR3-dependent IFN-α/β- and IFN-λ-mediated immunity in the CNS can underlie herpes simplex virus 1 (HSV-1) encephalitis (HSE). The respective contributions of IFN-α/β and IFN-λ are unknown. We report a child homozygous for a genomic deletion of the entire coding sequence and part of the 3'-UTR of the last exon of IFNAR1, who died of HSE at the age of 2 years. An older cousin died following vaccination against measles, mumps, and rubella at 12 months of age, and another 17-year-old cousin homozygous for the same variant has had other, less severe, viral illnesses. The encoded IFNAR1 protein is expressed on the cell surface but is truncated and cannot interact with the tyrosine kinase TYK2. The patient's fibroblasts and EBV-B cells did not respond to IFN-α2b or IFN-β, in terms of STAT1, STAT2, and STAT3 phosphorylation or the genome-wide induction of IFN-stimulated genes. The patient's fibroblasts were susceptible to viruses, including HSV-1, even in the presence of exogenous IFN-α2b or IFN-β. HSE is therefore a consequence of inherited complete IFNAR1 deficiency. This viral disease occurred in natural conditions, unlike those previously reported in other patients with IFNAR1 or IFNAR2 deficiency. This experiment of nature indicates that IFN-α/β are essential for anti-HSV-1 immunity in the CNS.
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http://dx.doi.org/10.1172/JCI139980DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7773360PMC
January 2021

Inherited human IFN-γ deficiency underlies mycobacterial disease.

J Clin Invest 2020 06;130(6):3158-3171

INSERM U1163, Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM 1163, Paris, France.

Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by a selective predisposition to clinical disease caused by the Bacille Calmette-Guérin (BCG) vaccine and environmental mycobacteria. The known genetic etiologies of MSMD are inborn errors of IFN-γ immunity due to mutations of 15 genes controlling the production of or response to IFN-γ. Since the first MSMD-causing mutations were reported in 1996, biallelic mutations in the genes encoding IFN-γ receptor 1 (IFN-γR1) and IFN-γR2 have been reported in many patients of diverse ancestries. Surprisingly, mutations of the gene encoding the IFN-γ cytokine itself have not been reported, raising the remote possibility that there might be other agonists of the IFN-γ receptor. We describe 2 Lebanese cousins with MSMD, living in Kuwait, who are both homozygous for a small deletion within the IFNG gene (c.354_357del), causing a frameshift that generates a premature stop codon (p.T119Ifs4*). The mutant allele is loss of expression and loss of function. We also show that the patients' herpesvirus Saimiri-immortalized T lymphocytes did not produce IFN-γ, a phenotype that can be rescued by retrotransduction with WT IFNG cDNA. The blood T and NK lymphocytes from these patients also failed to produce and secrete detectable amounts of IFN-γ. Finally, we show that human IFNG has evolved under stronger negative selection than IFNGR1 or IFNGR2, suggesting that it is less tolerant to heterozygous deleterious mutations than IFNGR1 or IFNGR2. This may account for the rarity of patients with autosomal-recessive, complete IFN-γ deficiency relative to patients with complete IFN-γR1 and IFN-γR2 deficiencies.
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http://dx.doi.org/10.1172/JCI135460DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7260033PMC
June 2020

Fatal Cytomegalovirus Infection in an Adult with Inherited NOS2 Deficiency.

N Engl J Med 2020 01;382(5):437-445

From St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, Rockefeller University (S.B.D., D.H., N.H., S.B., F.R., B.B., R.F., E.J., J.B., L.A., S.B.-D., J.-L.C.), the Department of Microbiology and Immunology, Weill Cornell Medicine (R.B., C.N.), and Howard Hughes Medical Institute (J.-L.C.) - all in New York; the Pediatric Respiratory Diseases Research Center (D.M., S.A.M.), the Department of Clinical Immunology and Infectious Diseases (D.M., N. Mansouri), and the Clinical Tuberculosis and Epidemiology Research Center (D.M., M.M.), National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran; the Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM Unité 1163 (A.-L.N., L.L.-D., E.J., J.B., L.A., S.B.-D., V.B., J.-L.C.), Paris University, Imagine Institute (A.-L.N., L.L.-D., E.J., J.B., L.A., S.B.-D., V.B., J.-L.C.), and the Study Center for Primary Immunodeficiencies, Assistance Publique-Hôpitaux de Paris (AP-HP) (J.B.), and the Pediatric Immunology-Hematology Unit (J.-L.C.), Necker Hospital for Sick Children, Paris, and the Department of Pathology, Ambroise Paré Hospital, AP-HP, Boulogne-Billancourt (J.-F.E.) - all in France; the Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany (A.-L.N.); the Research Branch, Sidra Medicine (M.R., T.K., F.A.A., N. Marr), and the College of Health and Life Sciences, Hamad Bin Khalifa University (N. Marr), Doha, Qatar; and the Division of Pulmonary Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland (N. Mansouri).

Background: Cytomegalovirus (CMV) can cause severe disease in children and adults with a variety of inherited or acquired T-cell immunodeficiencies, who are prone to multiple infections. It can also rarely cause disease in otherwise healthy persons. The pathogenesis of idiopathic CMV disease is unknown. Inbred mice that lack the gene encoding nitric oxide synthase 2 () are susceptible to the related murine CMV infection.

Methods: We studied a previously healthy 51-year-old man from Iran who after acute CMV infection had an onset of progressive CMV disease that led to his death 29 months later. We hypothesized that the patient may have had a novel type of inborn error of immunity. Thus, we performed whole-exome sequencing and tested candidate mutant alleles experimentally.

Results: We found a homozygous frameshift mutation in encoding a truncated NOS2 protein that did not produce nitric oxide, which determined that the patient had autosomal recessive NOS2 deficiency. Moreover, all variants that we found in homozygosity in public databases encoded functional proteins, as did all other variants with an allele frequency greater than 0.001.

Conclusions: These findings suggest that inherited NOS2 deficiency was clinically silent in this patient until lethal infection with CMV. Moreover, NOS2 appeared to be redundant for control of other pathogens in this patient. (Funded by the National Center for Advancing Translational Sciences and others.).
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http://dx.doi.org/10.1056/NEJMoa1910640DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063989PMC
January 2020

Chronic mucocutaneous candidiasis and connective tissue disorder in humans with impaired JNK1-dependent responses to IL-17A/F and TGF-β.

Sci Immunol 2019 11;4(41)

St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA.

Genetic etiologies of chronic mucocutaneous candidiasis (CMC) disrupt human IL-17A/F-dependent immunity at mucosal surfaces, whereas those of connective tissue disorders (CTDs) often impair the TGF-β-dependent homeostasis of connective tissues. The signaling pathways involved are incompletely understood. We report a three-generation family with an autosomal dominant (AD) combination of CMC and a previously undescribed form of CTD that clinically overlaps with Ehlers-Danlos syndrome (EDS). The patients are heterozygous for a private splice-site variant of , the gene encoding c-Jun N-terminal kinase 1 (JNK1), a component of the MAPK signaling pathway. This variant is loss-of-expression and loss-of-function in the patients' fibroblasts, which display AD JNK1 deficiency by haploinsufficiency. These cells have impaired, but not abolished, responses to IL-17A and IL-17F. Moreover, the development of the patients' T17 cells was impaired ex vivo and in vitro, probably due to the involvement of JNK1 in the TGF-β-responsive pathway and further accounting for the patients' CMC. Consistently, the patients' fibroblasts displayed impaired JNK1- and c-Jun/ATF-2-dependent induction of key extracellular matrix (ECM) components and regulators, but not of EDS-causing gene products, in response to TGF-β. Furthermore, they displayed a transcriptional pattern in response to TGF-β different from that of fibroblasts from patients with Loeys-Dietz syndrome caused by mutations of or , further accounting for the patients' complex and unusual CTD phenotype. This experiment of nature indicates that the integrity of the human JNK1-dependent MAPK signaling pathway is essential for IL-17A- and IL-17F-dependent mucocutaneous immunity to and for the TGF-β-dependent homeostasis of connective tissues.
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http://dx.doi.org/10.1126/sciimmunol.aax7965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014825PMC
November 2019

A curated transcriptome dataset collection to investigate inborn errors of immunity.

F1000Res 2019 15;8:188. Epub 2019 Feb 15.

Systems Biology and Immunology, Sidra Medicine, Doha, Qatar.

Primary immunodeficiencies (PIDs) are a heterogeneous group of inherited disorders, frequently caused by loss-of-function and less commonly by gain-of-function mutations, which can result in susceptibility to a broad or a very narrow range of infections but also in inflammatory, allergic or malignant diseases. Owing to the wide range in clinical manifestations and variability in penetrance and expressivity, there is an urgent need to better understand the underlying molecular, cellular and immunological phenotypes in PID patients in order to improve clinical diagnosis and management. Here we have compiled a manually curated collection of public transcriptome datasets mainly obtained from human whole blood, peripheral blood mononuclear cells (PBMCs) or fibroblasts of patients with PIDs and of control subjects for subsequent meta-analysis, query and interpretation. A total of eighteen (18) datasets derived from studies of PID patients were identified and retrieved from the NCBI Gene Expression Omnibus (GEO) database and loaded in GXB, a custom web application designed for interactive query and visualization of integrated large-scale data. The dataset collection includes samples from well characterized PID patients that were stimulated under a variety of conditions to assess the molecular consequences of the underlying, naturally occurring gene defects on a genome-wide scale. Multiple sample groupings and rank lists were generated to facilitate comparisons of the transcriptional responses between different PID patients and control subjects. The GXB tool enables browsing of a single transcript across studies, thereby providing new perspectives on the role of a given molecule across biological systems and PID patients. This dataset collection is available at http://pid.gxbsidra.org/dm3/geneBrowser/list.
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http://dx.doi.org/10.12688/f1000research.18048.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6749933PMC
June 2020

A deep intronic splice mutation of underlies hyper IgE syndrome by negative dominance.

Proc Natl Acad Sci U S A 2019 08 25;116(33):16463-16472. Epub 2019 Jul 25.

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR1163, 75015 Paris, France;

Heterozygous in-frame mutations in coding regions of human underlie the only known autosomal dominant form of hyper IgE syndrome (AD HIES). About 5% of familial cases remain unexplained. The mutant proteins are loss-of-function and dominant-negative when tested following overproduction in recipient cells. However, the production of mutant proteins has not been detected and quantified in the cells of heterozygous patients. We report a deep intronic heterozygous mutation, c.1282-89C>T, in 7 relatives with AD HIES. This mutation creates a new exon in the complementary DNA, which, when overexpressed, generates a mutant STAT3 protein (D427ins17) that is loss-of-function and dominant-negative in terms of tyrosine phosphorylation, DNA binding, and transcriptional activity. In immortalized B cells from these patients, the D427ins17 protein was 2 kDa larger and 4-fold less abundant than wild-type STAT3, on mass spectrometry. The patients' primary B and T lymphocytes responded poorly to STAT3-dependent cytokines. These findings are reminiscent of the impaired responses of leukocytes from other patients with AD HIES due to typical 3 coding mutations, providing further evidence for the dominance of the mutant intronic allele. These findings highlight the importance of sequencing introns in patients with HIES without candidate variants in coding regions and essential splice sites. They also show that AD HIES-causing mutant alleles can be dominant-negative even if the encoded protein is produced in significantly smaller amounts than wild-type STAT3.
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http://dx.doi.org/10.1073/pnas.1901409116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6697804PMC
August 2019

Inherited IFNAR1 deficiency in otherwise healthy patients with adverse reaction to measles and yellow fever live vaccines.

J Exp Med 2019 09 3;216(9):2057-2070. Epub 2019 Jul 3.

Department of Microbiology, Immunology and Transplantation, Clinical and Diagnostic Immunology, KU Leuven, Leuven, Belgium.

Vaccination against measles, mumps, and rubella (MMR) and yellow fever (YF) with live attenuated viruses can rarely cause life-threatening disease. Severe illness by MMR vaccines can be caused by inborn errors of type I and/or III interferon (IFN) immunity (mutations in , , or ). Adverse reactions to the YF vaccine have remained unexplained. We report two otherwise healthy patients, a 9-yr-old boy in Iran with severe measles vaccine disease at 1 yr and a 14-yr-old girl in Brazil with viscerotropic disease caused by the YF vaccine at 12 yr. The Iranian patient is homozygous and the Brazilian patient compound heterozygous for loss-of-function variations. Patient-derived fibroblasts are susceptible to viruses, including the YF and measles virus vaccine strains, in the absence or presence of exogenous type I IFN. The patients' fibroblast phenotypes are rescued with WT Autosomal recessive, complete IFNAR1 deficiency can result in life-threatening complications of vaccination with live attenuated measles and YF viruses in previously healthy individuals.
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http://dx.doi.org/10.1084/jem.20182295DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6719432PMC
September 2019

A curated transcriptome dataset collection to investigate the blood transcriptional response to viral respiratory tract infection and vaccination.

F1000Res 2019 13;8:284. Epub 2019 Mar 13.

Systems Biology and Immunology Department, Sidra Medicine, Doha, Qatar.

The human immune defense mechanisms and factors associated with good versus poor health outcomes following viral respiratory tract infections (VRTI), as well as correlates of protection following vaccination against respiratory viruses, remain incompletely understood. To shed further light into these mechanisms, a number of systems-scale studies have been conducted to measure transcriptional changes in blood leukocytes of either naturally or experimentally infected individuals, or in individual's post-vaccination. Here we are making available a public repository, for research investigators for interpretation, a collection of transcriptome datasets obtained from human whole blood and peripheral blood mononuclear cells (PBMC) to investigate the transcriptional responses following viral respiratory tract infection or vaccination against respiratory viruses. In total, Thirty one31 datasets, associated to viral respiratory tract infections and their related vaccination studies, were identified and retrieved from the NCBI Gene Expression Omnibus (GEO) and loaded in a custom web application designed for interactive query and visualization of integrated large-scale data. Quality control checks, using relevant biological markers, were performed. Multiple sample groupings and rank lists were created to facilitate dataset query and interpretation. Via this interface, users can generate web links to customized graphical views, which may be subsequently inserted into manuscripts to report novel findings. The GXB tool enables browsing of a single gene across projects, providing new perspectives on the role of a given molecule across biological systems in the diagnostic and prognostic following VRTI but also in identifying new correlates of protection. This dataset collection is available at: http://vri1.gxbsidra.org/dm3/geneBrowser/list.
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http://dx.doi.org/10.12688/f1000research.18533.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567289PMC
June 2020

A comparative study of the complete lipopolysaccharide structures and biosynthesis loci of Bordetella avium, B. hinzii, and B. trematum.

Biochimie 2019 Apr 19;159:81-92. Epub 2018 Dec 19.

LPS-BioSciences, Bâtiment 409, Université de Paris-Sud, Paris-Saclay, F-91405, Orsay, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université de Paris-Sud, Université Paris-Saclay, F-91405, Orsay, France. Electronic address:

A dozen species of human and animal pathogens have been described to date in the Bordetella genus, with the majority being respiratory tract pathogens. Bordetella avium lipopolysaccharides have been shown to be important virulence factors for this bird pathogen. B. hinzii is closely related to the B. avium species, but has also been isolated from humans. B. trematum is associated to ear and blood infections in humans. Its lipid A structure, the biological active moiety of LPS, was found to be closely related to those of B. avium and B. hinzii. It is important to unveil the subtle structural modifications orchestrated during the LPS biosynthetic pathway to better understand host adaptation. The present data are also important in the context of deciphering the virulence pathways of this important genus containing the major pathogens B. pertussis and B. parapertussis, responsible for whooping cough. We recently reported the isolated lipid A structures of the three presented species, following the previously identified O-chain structures. In the present study, we provide details on the free and O-chain-linked core oligosaccharides which were required to characterize the complete LPS structures. Data are presented here in relation to relevant biosynthesis genes. The present characterization of the three species is well illustrated by Matrix Assisted Laser Desorption Mass Spectrometry experiments, and data were obtained mainly on native LPS molecules for the first time.
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http://dx.doi.org/10.1016/j.biochi.2018.12.011DOI Listing
April 2019

Tuberculosis and impaired IL-23-dependent IFN-γ immunity in humans homozygous for a common missense variant.

Sci Immunol 2018 12;3(30)

St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, Rockefeller University, New York, NY, USA.

Inherited IL-12Rβ1 and TYK2 deficiencies impair both IL-12- and IL-23-dependent IFN-γ immunity and are rare monogenic causes of tuberculosis, each found in less than 1/600,000 individuals. We show that homozygosity for the common P1104A allele, which is found in about 1/600 Europeans and between 1/1000 and 1/10,000 individuals in regions other than East Asia, is more frequent in a cohort of patients with tuberculosis from endemic areas than in ethnicity-adjusted controls ( = 8.37 × 10; odds ratio, 89.31; 95% CI, 14.7 to 1725). Moreover, the frequency of P1104A in Europeans has decreased, from about 9% to 4.2%, over the past 4000 years, consistent with purging of this variant by endemic tuberculosis. Surprisingly, we also show that TYK2 P1104A impairs cellular responses to IL-23, but not to IFN-α, IL-10, or even IL-12, which, like IL-23, induces IFN-γ via activation of TYK2 and JAK2. Moreover, TYK2 P1104A is properly docked on cytokine receptors and can be phosphorylated by the proximal JAK, but lacks catalytic activity. Last, we show that the catalytic activity of TYK2 is essential for IL-23, but not IL-12, responses in cells expressing wild-type JAK2. In contrast, the catalytic activity of JAK2 is redundant for both IL-12 and IL-23 responses, because the catalytically inactive P1057A JAK2, which is also docked and phosphorylated, rescues signaling in cells expressing wild-type TYK2. In conclusion, homozygosity for the catalytically inactive P1104A missense variant of selectively disrupts the induction of IFN-γ by IL-23 and is a common monogenic etiology of tuberculosis.
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http://dx.doi.org/10.1126/sciimmunol.aau8714DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341984PMC
December 2018

Life-threatening influenza pneumonitis in a child with inherited IRF9 deficiency.

J Exp Med 2018 10 24;215(10):2567-2585. Epub 2018 Aug 24.

St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY

Life-threatening pulmonary influenza can be caused by inborn errors of type I and III IFN immunity. We report a 5-yr-old child with severe pulmonary influenza at 2 yr. She is homozygous for a loss-of-function allele. Her cells activate gamma-activated factor (GAF) STAT1 homodimers but not IFN-stimulated gene factor 3 (ISGF3) trimers (STAT1/STAT2/IRF9) in response to IFN-α2b. The transcriptome induced by IFN-α2b in the patient's cells is much narrower than that of control cells; however, induction of a subset of IFN-stimulated gene transcripts remains detectable. In vitro, the patient's cells do not control three respiratory viruses, influenza A virus (IAV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV). These phenotypes are rescued by wild-type IRF9, whereas silencing IRF9 expression in control cells increases viral replication. However, the child has controlled various common viruses in vivo, including respiratory viruses other than IAV. Our findings show that human IRF9- and ISGF3-dependent type I and III IFN responsive pathways are essential for controlling IAV.
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http://dx.doi.org/10.1084/jem.20180628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6170168PMC
October 2018

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

Sci Immunol 2018 06;3(24)

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, 75015 Paris, France.

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' 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.
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http://dx.doi.org/10.1126/sciimmunol.aat4956DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141026PMC
June 2018

IRF4 haploinsufficiency in a family with Whipple's disease.

Elife 2018 03 14;7. Epub 2018 Mar 14.

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France.

Most humans are exposed to (Tw). Whipple's disease (WD) strikes only a small minority of individuals infected with Tw (<0.01%), whereas asymptomatic chronic carriage is more common (<25%). We studied a multiplex kindred, containing four WD patients and five healthy Tw chronic carriers. We hypothesized that WD displays autosomal dominant (AD) inheritance, with age-dependent incomplete penetrance. We identified a single very rare non-synonymous mutation in the four patients: the private R98W variant of IRF4, a transcription factor involved in immunity. The five Tw carriers were younger, and also heterozygous for R98W. We found that R98W was loss-of-function, modified the transcriptome of heterozygous leukocytes following Tw stimulation, and was not dominant-negative. We also found that only six of the other 153 known non-synonymous IRF4 variants were loss-of-function. Finally, we found that had evolved under purifying selection. AD IRF4 deficiency can underlie WD by haploinsufficiency, with age-dependent incomplete penetrance.
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http://dx.doi.org/10.7554/eLife.32340DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5915175PMC
March 2018

Respiratory syncytial virus-neutralizing serum antibody titers in infants following palivizumab prophylaxis with an abbreviated dosing regimen.

PLoS One 2017 24;12(4):e0176152. Epub 2017 Apr 24.

Department of Pediatrics, University of British Columbia, Vancouver, Canada.

Background: Monthly injections of palivizumab during the respiratory syncytial virus (RSV) season in at-risk infants reduces RSV-associated hospitalizations. However, the additive effect of naturally acquired immunity remains unclear. The objective of this study was to assess total neutralizing serum antibodies (NAb) against RSV in at-risk infants who had received an abbreviated course of palivizumab prophylaxis.

Methods: Serum samples were collected from infants enrolled in the RSV Immunoprophylaxis Program in British Columbia, Canada over 2 consecutive RSV seasons (2013 to 2015). Infants in this program had received an abbreviated course of palivizumab in accordance with the provincial guidelines. Data were compared to adults and infants less than 12 months of age who did not receive palivizumab. Anti-RSV NAb titers were measured using an RSV microneutralization assay.

Findings: Infants who received palivizumab had anti-RSV NAb titers at the end of the RSV season that persisted beyond what is expected from the pharmacokinetics of palivizumab alone. Moreover, 54% of the control infants who did not receive palivizumab and all tested adults had protective anti-RSV NAb titers.

Conclusions: Based on our observations, we hypothesize that naturally acquired NAb provide additive protection, which may significantly reduce the need for additional doses of palivizumab in infants at risk of severe RSV infections.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0176152PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402955PMC
September 2017

Inherited human IRAK-1 deficiency selectively impairs TLR signaling in fibroblasts.

Proc Natl Acad Sci U S A 2017 01 9;114(4):E514-E523. Epub 2017 Jan 9.

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, 75015 Paris, France;

Most members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) families transduce signals via a canonical pathway involving the MyD88 adapter and the interleukin-1 receptor-associated kinase (IRAK) complex. This complex contains four molecules, including at least two (IRAK-1 and IRAK-4) active kinases. In mice and humans, deficiencies of IRAK-4 or MyD88 abolish most TLR (except for TLR3 and some TLR4) and IL-1R signaling in both leukocytes and fibroblasts. TLR and IL-1R responses are weak but not abolished in mice lacking IRAK-1, whereas the role of IRAK-1 in humans remains unclear. We describe here a boy with X-linked MECP2 deficiency-related syndrome due to a large de novo Xq28 chromosomal deletion encompassing both MECP2 and IRAK1 Like many boys with MECP2 null mutations, this child died very early, at the age of 7 mo. Unlike most IRAK-4- or MyD88-deficient patients, he did not suffer from invasive bacterial diseases during his short life. The IRAK-1 protein was completely absent from the patient's fibroblasts, which responded very poorly to all TLR2/6 (PAMCSK, LTA, FSL-1), TLR1/2 (PAMCSK), and TLR4 (LPS, MPLA) agonists tested but had almost unimpaired responses to IL-1β. By contrast, the patient's peripheral blood mononuclear cells responded normally to all TLR1/2, TLR2/6, TLR4, TLR7, and TLR8 (R848) agonists tested, and to IL-1β. The death of this child precluded long-term evaluations of the clinical consequences of inherited IRAK-1 deficiency. However, these findings suggest that human IRAK-1 is essential downstream from TLRs but not IL-1Rs in fibroblasts, whereas it plays a redundant role downstream from both TLRs and IL-1Rs in leukocytes.
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http://dx.doi.org/10.1073/pnas.1620139114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5278481PMC
January 2017

A curated transcriptome dataset collection to investigate the functional programming of human hematopoietic cells in early life.

F1000Res 2016 30;5:414. Epub 2016 Mar 30.

Sidra Medical and Research Center, Doha, Qatar.

Compendia of large-scale datasets made available in public repositories provide an opportunity to identify and fill gaps in biomedical knowledge. But first, these data need to be made readily accessible to research investigators for interpretation. Here we make available a collection of transcriptome datasets to investigate the functional programming of human hematopoietic cells in early life. Thirty two datasets were retrieved from the NCBI Gene Expression Omnibus (GEO) and loaded in a custom web application called the Gene Expression Browser (GXB), which was designed for interactive query and visualization of integrated large-scale data. Quality control checks were performed. Multiple sample groupings and gene rank lists were created allowing users to reveal age-related differences in transcriptome profiles, changes in the gene expression of neonatal hematopoietic cells to a variety of immune stimulators and modulators, as well as during cell differentiation. Available demographic, clinical, and cell phenotypic information can be overlaid with the gene expression data and used to sort samples. Web links to customized graphical views can be generated and subsequently inserted in manuscripts to report novel findings. GXB also enables browsing of a single gene across projects, thereby providing new perspectives on age- and developmental stage-specific expression of a given gene across the human hematopoietic system. This dataset collection is available at: http://developmentalimmunology.gxbsidra.org/dm3/geneBrowser/list.
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http://dx.doi.org/10.12688/f1000research.8375.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4916988PMC
June 2016

Outcomes of Respiratory Syncytial Virus Immunoprophylaxis in Infants Using an Abbreviated Dosing Regimen of Palivizumab.

JAMA Pediatr 2016 Feb;170(2):174-6

Children's & Women's Health Centre of British Columbia, University of British Columbia, Vancouver7Canadian Center for Vaccinology, Halifax, Nova Scotia8Sidra Medical and Research Center, Doha, Qatar.

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http://dx.doi.org/10.1001/jamapediatrics.2015.3235DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5647159PMC
February 2016

Respiratory syncytial virus infection of primary human mast cells induces the selective production of type I interferons, CXCL10, and CCL4.

J Allergy Clin Immunol 2015 Nov 24;136(5):1346-54.e1. Epub 2015 Mar 24.

Department of Microbiology and Immunology, Dalhousie Inflammation Group, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Pathology, Dalhousie Inflammation Group, Dalhousie University, Halifax, Nova Scotia, Canada. Electronic address:

Background: Respiratory syncytial virus (RSV) causes severe respiratory tract infections, which might have a role in the development of airway hyperreactivity. Mast cells are important effector cells in allergy, with sentinel cell roles in host defense. However, the role of mast cells in response to RSV infection is unknown.

Objective: Human mast cell responses to RSV were investigated with a view to better understanding the role of mast cells in RSV-induced disease.

Methods: Human cord blood-derived mast cells and the HMC-1 mast cell line were exposed to RSV or UV-inactivated RSV. Viral gene and protein expression were evaluated by using PCR and flow cytometry. The expression of interferon-stimulated genes and selected mediators were evaluated by using quantitative PCR and ELISA.

Results: Human mast cells expressed multiple RSV genes after exposure to RSV, and a small percentage of mast cells supported RSV antigen protein expression. RSV induced mast cells to upregulate production of chemokines, including CCL4, CCL5, and CXCL10, as well as type I interferons, and interferon-stimulated gene expression. However, production of the granulocyte chemoattractants CXCL8 and CCL11 was not induced. Antibody blockade of the type I interferon receptor on human cord blood-derived mast cells reduced the RSV-mediated induction of CXCL10 and CCL4 but not CCL5. Leukotriene C4 production by mast cells was not enhanced by exposure to RSV.

Conclusion: Despite low levels of infection, human mast cells produce multiple chemokines in response to RSV through mechanisms that include responses to type I interferons. Such mast cell responses might enhance effector cell recruitment during RSV-induced disease.
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http://dx.doi.org/10.1016/j.jaci.2015.01.042DOI Listing
November 2015

Assessment of genetic associations between common single nucleotide polymorphisms in RIG-I-like receptor and IL-4 signaling genes and severe respiratory syncytial virus infection in children: a candidate gene case-control study.

PLoS One 2014 20;9(6):e100269. Epub 2014 Jun 20.

Department of Pediatrics, University of British Columbia, Child and Family Research Institute, Vancouver, British Columbia, Canada.

The majority of cases of severe pediatric respiratory syncytial virus (RSV) infection occur in otherwise healthy infants who have no identifiable risk factors, suggesting that additional subclinical factors, such as population genetic variation, influence the course of RSV infection. The objective of this study was to test if common single nucleotide polymorphisms (SNPs) in genes encoding for immune signalling components of the RIG-I-like receptor (RLR) and IL-4-signalling pathways affect the outcome of RSV infection in early life. We genotyped 8 SNPs using allele-specific probes combined with real-time PCR. Each of the SNPs tested had previously been established to have a functional impact on immune responsiveness and two of the SNPs in the IL4 and IL4R genes had previously been associated with severe RSV bronchiolitis. Association with susceptibility to severe RSV infection was tested by statistically comparing genotype and allele frequencies in infants and young children hospitalized with severe RSV bronchiolitis (n = 140) with two control groups-children who tested positive for RSV but did not require hospitalization (n = 100), and a general population control group (n = 285). Our study was designed with sufficient power (>80%) to detect clinically-relevant associations with effect sizes ≥1.5. However, we detected no statistically significant differences in allele and genotype frequencies of the investigated SNPs between the inpatient and control groups. To conclude, we could not replicate the previously reported association with SNPs in the IL4 and IL4R genes in our independent cohort, nor did we find that common SNPs in genes encoding for RLRs and the downstream adapter MAVS were associated with susceptibility to severe RSV infections. Despite the existing evidence demonstrating a functional immunological impact of these SNPs, our data suggest that the biological effect of each individual SNP is unlikely to affect clinical outcomes of RSV infection.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0100269PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064989PMC
February 2015

Hierarchical maturation of innate immune defences in very preterm neonates.

Neonatology 2014 6;106(1):1-9. Epub 2014 Mar 6.

Child and Family Research Institute, Vancouver, B.C., Canada.

Background: Preterm neonates are highly vulnerable to infection.

Objectives: To investigate the developmental contribution of prematurity, chorioamnionitis and antenatal corticosteroids (ANS) on the maturation of neonatal microbial pathogen recognition responses.

Methods: Using standardized protocols, we assayed multiple inflammatory cytokine responses (IL-1β, IL-6, TNF-α and IL-12/23p40) to three prototypic Toll-like receptor (TLR) agonists, i.e. TLR4 (lipopolysaccharide), TLR5 (flagellin) and TLR7/8 (R848), and to the non-TLR retinoic acid-inducible gene I (RIG-I)-like receptor agonist, in cord blood mononuclear cells from neonates born before 33 weeks of gestation and at term.

Results: TLR responses develop asynchronously in preterm neonates, whereby responses to TLR7/8 were more mature and were followed by the development of TLR4 responses, which were also heterogeneous. Responses to TLR5 were weakest and most immature. Maturity in TLR responses was not influenced by sex. Overall, we detected no significant contribution of ANS and chorioamnionitis to the developmental attenuation of either TLR or RIG-I responses.

Conclusions: The maturation of anti-microbial responses in neonates born early in gestation follows an asynchronous developmental hierarchy independently of an exposure to chorioamnionitis and ANS. Our data provide an immunological basis for the predominance of specific microbial infections in this age group.
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http://dx.doi.org/10.1159/000358550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4556450PMC
March 2015

Attenuation of respiratory syncytial virus-induced and RIG-I-dependent type I IFN responses in human neonates and very young children.

J Immunol 2014 Feb 3;192(3):948-57. Epub 2014 Jan 3.

Department of Pediatrics, University of British Columbia and Children's and Women's Health Centre of British Columbia, Vancouver, British Columbia V6H 3V4, Canada.

Newborn infants, including those born at term without congenital disorders, are at high risk of severe disease from respiratory syncytial virus (RSV) infection. Indeed, our current local surveillance data demonstrate that approximately half of children hospitalized with RSV were ≤3 mo old, and 74% were born at term. Informed by this clinical epidemiology, we investigated antiviral innate immune responses in early life, with the goal of identifying immunological factors underlying the susceptibility of infants and young children to severe viral lower respiratory tract infections. We compared RSV-induced innate cytokine production in blood mononuclear cells from neonates, young children aged 12-59 mo, and healthy adults. RSV-induced IFN-α production was primarily mediated by plasmacytoid dendritic cells (pDCs), and was significantly lower in term infants and young children < 5 y of age than in adults (p < 0.01). RSV-induced IFN-α production in human pDCs proceeded independently of endosomal TLRs, and human pDCs from healthy adult donors produced IFN-α in a retinoic acid-inducible gene I protein (RIG-I)-dependent manner. Of interest, young age and premature birth were independently associated with attenuated RIG-I-dependent IFN-α responses (p < 0.01). In contrast to IFN-α production, proinflammatory IL-6 responses to RSV were mediated by monocytes, appeared less dependent on RIG-I, and were significantly impaired only among preterm infants, not in term infants and young children. Our results suggest that human pDCs are less functional in early life, which may contribute to the increased susceptibility of infants and young children to severe RSV disease.
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http://dx.doi.org/10.4049/jimmunol.1302007DOI Listing
February 2014

Combined immunodeficiency associated with homozygous MALT1 mutations.

J Allergy Clin Immunol 2014 May 12;133(5):1458-62, 1462.e1-7. Epub 2013 Dec 12.

Department of Pediatrics, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2013.10.045DOI Listing
May 2014

Pathogen recognition receptor crosstalk in respiratory syncytial virus sensing: a host and cell type perspective.

Trends Microbiol 2013 Nov 9;21(11):568-74. Epub 2013 Oct 9.

Department of Pediatrics, University of British Columbia, Vancouver, BC V6H 3V4, Canada; Child & Family Research Institute, Vancouver, BC V5Z 4H4, Canada.

Human respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in young children, immunocompromised adults, and the elderly. The innate immune response plays a pivotal role in host defense against RSV, but whether severe outcomes following RSV infection result from excessive or poor innate immune recognition remains unclear. Recent research suggests a situation in which crosstalk between families of pattern recognition receptors (PRRs) occurs in a cell type-dependent manner. The current challenge to empower novel therapeutic approaches and vaccine development is to confirm the role of the individual receptors in RSV pathogenesis in humans.
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http://dx.doi.org/10.1016/j.tim.2013.08.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848032PMC
November 2013

IL-4Rα on CD4+ T cells plays a pathogenic role in respiratory syncytial virus reinfection in mice infected initially as neonates.

J Leukoc Biol 2013 Jun 29;93(6):933-42. Epub 2013 Mar 29.

Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.

RSV is the major cause of severe bronchiolitis in infants, and severe bronchiolitis as a result of RSV is associated with subsequent asthma development. A biased Th2 immune response is thought to be responsible for neonatal RSV pathogenesis; however, molecular mechanisms remain elusive. Our data demonstrate, for the first time, that IL-4Rα is up-regulated in vitro on human CD4(+) T cells from cord blood following RSV stimulation and in vivo on mouse pulmonary CD4(+) T cells upon reinfection of mice, initially infected as neonates. Th cell-specific deletion of Il4ra attenuated Th2 responses and abolished the immunopathophysiology upon reinfection, including airway hyper-reactivity, eosinophilia, and mucus hyperproduction in mice infected initially as neonates. These findings support a pathogenic role for IL-4Rα on Th cells following RSV reinfection of mice initially infected as neonates; more importantly, our data from human cells suggest that the same mechanism occurs in humans.
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http://dx.doi.org/10.1189/jlb.1012498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3656337PMC
June 2013