Kathrin Suttner

HLX1 gene variants influence the development of childhood asthma.

BACKGROUND Major transcription factors controlling T(H)1 and T(H)2 development, such as T-box transcription factor and GATA3, might be centrally involved in asthma and atopic diseases. Only recently, the homeobox transcription factor H.20-like homeobox 1 (HLX1), interacting closely with T-box transcription factor, has been identified as an important regulator of T(H)1 differentiation and suppressor of T(H)2 commitment. OBJECTIVE We investigated whether genetic variations in the HLX1 gene exist and whether these could affect the development of childhood asthma. METHODS The HLX1 gene was resequenced in 80 chromosomes. Associations between identified polymorphisms, asthma, and atopic diseases were investigated in German children (total n = 3099) from the cross-sectional International Study of Asthma and Allergy in Childhood phase II. Functional properties of polymorphisms were studied by using luciferase reporter gene assays and electrophoretic mobility shift assays in T cells. All statistical analyses were performed with SAS/Genetics software (SAS Institute, Inc, Cary, NC). RESULTS Nineteen polymorphisms were identified in the HLX1 gene, and 2 tagging single nucleotide polymorphisms representing 7 polymorphisms were associated with childhood asthma in our study population. Two promoter polymorphisms, C-1407T and C-742G, contained in 1 tagging block were associated with asthma (odds ratio, 1.44; 95% CI, 1.11-1.86; P = .0061), significantly decrease promoter transactivation, and disrupt specificity protein-transcription factor binding in in vitro experiments. CONCLUSIONS Our data suggest that polymorphisms in the HLX1 gene increase the risk for childhood asthma. On the cellular level, altered binding of specificity protein-transcription factors to the HLX1 promoter and subsequent changes in HLX1 gene expression might contribute to these effects.

A Combined Omics Approach to Generate the Surface Atlas of Human Naive CD4+ T Cells during Early T-Cell Receptor Activation

Naive CD4+ T cells are the common precursors of multiple effector and memory T-cell subsets and possess a high plasticity in terms of differentiation potential. This stem-cell-like character is important for cell therapies aiming at regeneration of specific immunity. Cell surface proteins are crucial for recognition and response to signals mediated by other cells or environmental changes. Knowledge of cell surface proteins of human naive CD4+ T cells and their changes during the early phase of T-cell activation is urgently needed for a guided differentiation of naive T cells and may support the selection of pluripotent cells for cell therapy. Periodate oxidation and aniline-catalyzed oxime ligation technology was applied with subsequent quantitative liquid chromatography-tandem MS to generate a data set describing the surface proteome of primary human naive CD4+ T cells and to monitor dynamic changes during the early phase of activation. This led to the identification of 173 N-glycosylated surface proteins. To independently confirm the proteomic data set and to analyze the cell surface by an alternative technique a systematic phenotypic expression analysis of surface antigens via flow cytometry was performed. This screening expanded the previous data set, resulting in 229 surface proteins, which were expressed on naive unstimulated and activated CD4+ T cells. Furthermore, we generated a surface expression atlas based on transcriptome data, experimental annotation, and predicted subcellular localization, and correlated the proteomics result with this transcriptional data set. This extensive surface atlas provides an overall naive CD4+ T cell surface resource and will enable future studies aiming at a deeper understanding of mechanisms of T-cell biology allowing the identification of novel immune targets usable for the development of therapeutic treatments.

Genetic variants in Protocadherin-1, bronchial hyper-responsiveness, and asthma subphenotypes in German children

To cite this article: Toncheva AA, Suttner K, Michel S, Klopp N, Illig T, Balschun T, Vogelberg C, von Berg A, Bufe A, Heinzmann A, Laub O, Rietschel E, Simma B, Frischer T, Genuneit J, von Mutius E, Kabesch M. Genetic variants in Protocadherin‐1, bronchial hyper‐responsiveness, and asthma subphenotypes in German children. Pediatr Allergy Immunol 2012.

Genetic variants harbored in the forkhead box protein 3 locus increase hay fever risk.

SLC11A1 gene might have an impact on intracellular bacteria infection and leishmaniasis. Additional observations strengthening our initial hypothesis of cPLA2a contribution to asthma pathogenesis are data on comparative analysis of cPLA2a mRNA and protein expression in patients and healthy subjects randomly selected regardless of genotypes. Although we found similar expression of cPLA2a in patients with severe and nonsevere asthma, it was still strongly overexpressed compared with healthy controls. Obviously, the overall high prevalence of shorter alleles of studied microsatellites in patients with severe asthma, which was shown in our previous study, might influence such results. On the other hand, the selection was performed at random according to drawing of lots from all patients with asthma treated in our unit. Although high expression of cPLA2a in patients with asthma did not increase generation of eicosanoids by PBMCs, it might act locally in the bronchi, delivering arachidonic acid for enzymes of eicosanoids pathway at the direct site of inflammation. It could also influence other proinflammatory gene expression. In summary, our data suggest that (CA)n and (T)n microsatellites in the PLA2G4A promoter determine cPLA2a in vivo expression in patients with severe asthma and the overexpression of cPLA2a in persistent asthma might play a role in its pathogenesis. Milena Sokolowska, MD, PhD Joanna Stefanska, MSc Karolina Wodz-Naskiewicz, MSc Malgorzata Cieslak, MD Rafal Pawliczak, MD, PhD From the Department of Immunopathology, Chair of Allergology, Immunology and Dermatology, Faculty of Biomedical Sciences and Postgraduate Training; and the Department of Immunology, Rheumatology and Allergy, Faculty of Medicine, Medical University of Lodz, Poland. E-mail: rafal.pawliczak@csk.umed.lodz.pl. Supported by Polish Government grants N N401 225034 and N401 191 32/4009. Disclosure of potential conflict of interest: The authors have declared that they have no conflict of interest.

Genetic variants in the GATA3 gene are not associated with asthma and atopic diseases in German children

To the Editor: In asthma and atopy a disturbed regulation of T cells can lead to an imbalance between TH1 and TH2 cells and toward an increased TH2 response. The transcription factor GATA3 is necessary and sufficient for the differentiation of naive T cells into TH2 cells and also the maintenance of TH2 cytokine expression (IL-4, IL-5, and IL-13) in already differentiated TH2 cells. 1 GATA3 is not only involved in T-cell regulation but directly influences asthma symptoms and development. Selectively silencing GATA3, Sel et al recently demonstrated the essential involvement of GATA3 in the development of asthma in a murine model of acute experimental allergic asthma. Thus the aim of the present study was to investigate whether polymorphisms in the GATA3 gene exist that might affect TH cell differentiation and influence the pathogenesis of asthma and allergy. By using the HapMap database, GATA3 polymorphisms (minor allele frequency 3%) were identified and genotyped by means of matrix-assisted laser desorption/ionization time of flight mass spectrometry in German children from Munich (n 5 1159) and Dresden (n 5 1940) recruited in the cross-sectional International Study of Asthma and Allergy in Childhood phase II and children from Leipzig (n 5 1165) phenotyped with a similar protocol. The prevalence of asthma and allergies was assessed by means of self-administered questionnaires and objective measurements, such as lung function tests, skin prick tests, and serum IgE measurements. Further information on primer sequences, technical details, or population characteristics are available from the corresponding author on request.

Early IL-10 producing B-cells and coinciding Th/Tr17 shifts during three year grass-pollen AIT

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