title: Identification of novel immune phenotypes for allergic and nonallergic childhood asthma.
abstract: BACKGROUND
  Childhood asthma is classified into allergic asthma (AA) and nonallergic asthma (NA), yet both are treated identically, with only partial success.
  
  
  OBJECTIVE
  We sought to identify novel immune phenotypes for childhood AA and NA.
  
  
  METHODS
  The Clinical Asthma Research Association cohort study includes 275 steroid-naive 4- to 15-year-old German children (healthy control subjects [HCs], patients with AA, and patients with NA). In PBMCs both quantitative and functional analysis of regulatory T (Treg) and TH17 cells (flow cytometry/Treg cell suppression) before/after anti-CD3/CD28, lipid A, and peptidoglycan stimulation were performed. Cytokines and gene expression, as assessed by using Luminex or transcriptomics/quantitative real-time RT-PCR, were analyzed by means of regression analysis. Linear discriminant analysis was applied to discriminate between phenotypes.
  
  
  RESULTS
  The 3 phenotypes were immunologically well discriminated by means of microarray and protein analysis with linear discriminant analysis. Patients with AA were characterized by increased Treg cells compared with those in HCs but not those in patients with NA. Treg cells from patients with AA, but not patients with NA, significantly suppressed IL-5, IL-13, and IFN-γ secretion. Patients with AA had decreased expression of chloride intracellular channel 4 (CLIC4) and tuberous sclerosis 1 (TSC1), important innate immunity regulators. Patients with NA were characterized by increased proinflammatory IL-1β levels, neutrophil counts, and IL-17-shifted immunity. In parallel, expressions of anti-inflammatory IL37, proline-serine-threonine phosphatase-interacting protein 2 (PSTPIP2), and the neutrophil-associated genes CD93, triggering receptor expressed on myeloid cells 1 (TREM1), and regulator of G-protein signaling 13 (RGS13) were increased in patients with NA. A shared TH2 immunity was present in both asthma phenotypes.
  
  
  CONCLUSIONS
  Novel immune-regulatory mechanisms in childhood asthma identified increased Treg cells in patients with AA compared with those in HCs but not those in NA and decreased innate immunity genes for patients with AA, the first potentially indicating a counterregulatory mechanism to suppress cytokines yet not sufficient to control allergic inflammation. Very distinctly, patients with NA showed an IL-17-shifted proinflammatory immunity, promoting neutrophil inflammation and less functional Treg cells. Identification of these unique pathways provides a profound basis for future strategies for individualized prediction of asthma development, disease course, and prevention.
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Raedler
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Ballenberger
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Klucker
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Böck
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Ragna
authors.initials: R
authors.lastname: Otto
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, TUM Munich, Munich, Germany.
authors.forename: Olivia
authors.initials: O
authors.lastname: Prazeres da Costa
authors.affiliation: Division of Structural Biochemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany.
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
authors.affiliation: Institute of Epidemiology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany; Hannover Unified Biobank, Hannover Medical School, Hannover, Germany; German Center for Lung Research (DZL), Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Illig
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, TUM Munich, Munich, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Buch
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: von Mutius
authors.affiliation: University Children's Hospital Munich, the Department of Pulmonary & Allergy, LMU Munich, Member of the German Center for Lung Research (DZL), Munich, Germany. Electronic address: Bianca.Schaub@med.uni-muenchen.de.
authors.forename: Bianca
authors.initials: B
authors.lastname: Schaub
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000276:immunology; D000293:Adolescent; D001249:Asthma / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D018118:Chloride Channels / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D003598:Cytoskeletal Proteins / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology; D010641:Phenotype; D020710:RGS Proteins / Q000276:immunology; D011951:Receptors, Complement / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins / Q000276:immunology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C464459:CLIC4 protein, human; D018118:Chloride Channels; D016207:Cytokines; D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; C486384:PSTPIP2 protein, human; D020710:RGS Proteins; C456322:RGS13 protein, human; D011951:Receptors, Complement; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; C000624650:TSC1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins; C032402:complement 1q receptor
keywords: Childhood asthma phenotypes; immune-regulatory mechanisms; innate immunity; linear discriminant analysis; peripheral blood mononuclear cells; regulatory T cells; transcriptomics