title: Targeted Resequencing and Functional Testing Identifies Low-Frequency Missense Variants in the Gene Encoding GARP as Significant Contributors to Atopic Dermatitis Risk.
abstract: Gene-mapping studies have consistently identified a susceptibility locus for atopic dermatitis and other inflammatory diseases on chromosome band 11q13.5, with the strongest association observed for a common variant located in an intergenic region between the two annotated genes C11orf30 and LRRC32. Using a targeted resequencing approach we identified low-frequency and rare missense mutations within the LRRC32 gene encoding the protein GARP, a receptor on activated regulatory T cells that binds latent transforming growth factor-β. Subsequent association testing in more than 2,000 atopic dermatitis patients and 2,000 control subjects showed a significant excess of these LRRC32 variants in individuals with atopic dermatitis. Structural protein modeling and bioinformatic analysis predicted a disruption of protein transport upon these variants, and overexpression assays in CD4+CD25-T cells showed a significant reduction in surface expression of the mutated protein. Consistently, flow cytometric (FACS) analyses of different T-cell subtypes obtained from atopic dermatitis patients showed a significantly reduced surface expression of GARP and a reduced conversion of CD4+CD25-T cells into regulatory T cells, along with lower expression of latency-associated protein upon stimulation in carriers of the LRRC32 A407T variant. These results link inherited disturbances of transforming growth factor-β signaling with atopic dermatitis risk.
authors.affiliation: Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Manz
authors.affiliation: Department of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Rodríguez
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany; Faculty of Sciences, Division of Biochemistry, Chemistry Department, Damietta University, New Damietta City, Egypt.
authors.forename: Abdou
authors.initials: A
authors.lastname: ElSharawy
authors.affiliation: Department of Dermatology and Allergy, University Hospital Bonn, Bonn, Germany.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Oesau
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: Britt-Sabina
authors.initials: BS
authors.lastname: Petersen
authors.affiliation: Department of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Baurecht
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Mayr
authors.affiliation: Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Weber
authors.affiliation: Department of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Harder
authors.affiliation: Research Unit of Molecular Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Reischl
authors.affiliation: Department of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Agatha
authors.initials: A
authors.lastname: Schwarz
authors.affiliation: Department of Dermatology and Allergy, University Hospital Bonn, Bonn, Germany.
authors.forename: Natalija
authors.initials: N
authors.lastname: Novak
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Franke
authors.affiliation: Department of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany. Electronic address: sweidinger@dermatology.uni-kiel.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Weidinger
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002478:Cells, Cultured; D002874:Chromosome Mapping; D003876:Dermatitis, Atopic / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018570:Risk Assessment; D017384:Sequence Deletion; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000473:pathology
chemical_list: C087215:LRRC32 protein, human; D008565:Membrane Proteins; D012333:RNA, Messenger