HZI Collection:

Maternal farm exposure modulates neonatal immune mechanisms through regulatory T cells.

Wed, 01 Apr 2009 00:00:00 GMT

Title: Maternal farm exposure modulates neonatal immune mechanisms through regulatory T cells. Authors: Schaub, Bianca; Liu, Jing; Höppler, Sabine; Schleich, Isolde; Huehn, Jochen; Olek, Sven; Wieczorek, Georg; Illi, Sabina; von Mutius, Erika Abstract: BACKGROUND: Cross-sectional studies suggest that maternal exposure to farming decreases the risk of allergic diseases in offspring. The potential underlying immunologic mechanisms are not understood. OBJECTIVE: We sought to assess whether maternal farm exposure activates regulatory T (Treg) cells in cord blood, exerting T(H)2-suppressive effects after microbial stimulation. METHODS: Eighty-four pregnant mothers were recruited before delivery. Detailed questionnaires (60 nonfarming and 22 farming mothers with 2 exclusions) assessed the farming exposures. Cord blood was stimulated with the microbial stimulus peptidoglycan (Ppg), the mitogen PHA, house dust mite extracts (Der p 1), and combinations. Treg cells (CD4+CD25(high) cells; intracellular forkhead/winged-helix family transcriptional repressor p3 [FOXP3] expression, FOXP3 levels, lymphocyte activation gene 3 mRNA expression, functional studies, and DNA methylation of the FOXP3 locus), proliferation, and T(H)2/T(H)1/T(H)17 cytokines were examined. RESULTS: Cord blood Treg cell counts (both unstimulated and PHA stimulated) were increased with maternal farming exposures and associated with higher FOXP3 (Der p 1 + Ppg stimulation) and trendwise higher lymphocyte activation gene 3 (Ppg) expression. Furthermore, Treg cell function was more efficient with farming exposure (effector cell suppression, P = .004). In parallel, T(H)2 cytokine (IL-5) levels were decreased and associated with decreased lymphoproliferation and increased IL-6 levels (Ppg stimulation, Der p 1 + Ppg stimulation, or both; P < .05). Maternal exposure to increasing numbers of farm animals and stables was discovered to exert distinct effects on Treg cells, T(H)1/T(H)2 cells, or both. Additionally, FOXP3 demethylation in offspring of mothers with farm milk exposure was increased (P = .02). CONCLUSIONS: Farm exposures during pregnancy increase the number and function of cord blood Treg cells associated with lower T(H)2 cytokine secretion and lymphocyte proliferation on innate exposure. One fascinating speculation is that maternal farm exposure might reflect a natural model of immunotherapy, potentially including a selection of innate stimuli in addition to allergen, shaping a child's immune system at an early stage.

Mouse Phenotype Database Integration Consortium: integration [corrected] of mouse phenome data resources.

Thu, 01 Mar 2007 00:00:00 GMT

Title: Mouse Phenotype Database Integration Consortium: integration [corrected] of mouse phenome data resources. Authors: Hancock, John M; Adams, Niels C; Aidinis, Vassilis; Blake, Andrew; Bogue, Molly; Brown, Steve D M; Chesler, Elissa J; Davidson, Duncan; Duran, Christopher; Eppig, Janan T; Gailus-Durner, Valérie; Gates, Hilary; Gkoutos, Georgios V; Greenaway, Simon; Hrabé de Angelis, Martin; Kollias, George; Leblanc, Sophie; Lee, Kirsty; Lengger, Christoph; Maier, Holger; Mallon, Ann-Marie; Masuya, Hiroshi; Melvin, David G; Müller, Werner; Parkinson, Helen; Proctor, Glenn; Reuveni, Eli; Schofield, Paul; Shukla, Aadya; Smith, Cynthia; Toyoda, Tetsuro; Vasseur, Laurent; Wakana, Shigeharu; Walling, Alison; White, Jacqui; Wood, Joe; Zouberakis, Michalis Abstract: Understanding the functions encoded in the mouse genome will be central to an understanding of the genetic basis of human disease. To achieve this it will be essential to be able to characterize the phenotypic consequences of variation and alterations in individual genes. Data on the phenotypes of mouse strains are currently held in a number of different forms (detailed descriptions of mouse lines, first-line phenotyping data on novel mutations, data on the normal features of inbred lines) at many sites worldwide. For the most efficient use of these data sets, we have initiated a process to develop standards for the description of phenotypes (using ontologies) and file formats for the description of phenotyping protocols and phenotype data sets. This process is ongoing and needs to be supported by the wider mouse genetics and phenotyping communities to succeed. We invite interested parties to contact us as we develop this process further.

Constitutive CD40 signaling in B cells selectively activates the noncanonical NF-kappaB pathway and promotes lymphomagenesis.

Mon, 09 Jun 2008 00:00:00 GMT

Title: Constitutive CD40 signaling in B cells selectively activates the noncanonical NF-kappaB pathway and promotes lymphomagenesis. Authors: Hömig-Hölzel, Cornelia; Hojer, Caroline; Rastelli, Julia; Casola, Stefano; Strobl, Lothar J; Müller, Werner; Quintanilla-Martinez, Leticia; Gewies, Andreas; Ruland, Jürgen; Rajewsky, Klaus; Zimber-Strobl, Ursula Abstract: CD40, a member of the tumor necrosis factor (TNF) receptor family, plays an essential role in T cell-dependent immune responses. Because CD40 is widely expressed on the surface of tumor cells in various B cell malignancies, deregulated CD40 signaling has been suggested to contribute to lymphomagenesis. In this study, we show that B cell-specific expression of a constitutively active CD40 receptor, in the form of a latent membrane protein 1 (LMP1)/CD40 chimeric protein, promoted an increase in the number of follicular and marginal zone B cells in secondary lymphoid organs in transgenic mice. The B cells displayed an activated phenotype, prolonged survival and increased proliferation, but were significantly impaired in T cell-dependent immune responses. Constitutive CD40 signaling in B cells induced selective and constitutive activation of the noncanonical NF-kappaB pathway and the mitogen-activated protein kinases Jnk and extracellular signal-regulated kinase. LMP1/CD40-expressing mice older than 12 mo developed B cell lymphomas of mono- or oligoclonal origin at high incidence, thus showing that the interplay of the signaling pathways induced by constitutive CD40 signaling is sufficient to initiate a tumorigenic process, ultimately leading to the development of B cell lymphomas.

LMP1 signaling can replace CD40 signaling in B cells in vivo and has unique features of inducing class-switch recombination to IgG1.

Fri, 01 Feb 2008 00:00:00 GMT

Title: LMP1 signaling can replace CD40 signaling in B cells in vivo and has unique features of inducing class-switch recombination to IgG1. Authors: Rastelli, Julia; Hömig-Hölzel, Cornelia; Seagal, Jane; Müller, Werner; Hermann, Andrea C; Rajewsky, Klaus; Zimber-Strobl, Ursula Abstract: The Epstein-Barr virus (EBV) protein LMP1 is considered to be a functional homologue of the CD40 receptor. However, in contrast to the latter, LMP1 is a constitutively active signaling molecule. To compare B cell-specific LMP1 and CD40 signaling in an unambiguous manner, we generated transgenic mice conditionally expressing a CD40/LMP1 fusion protein, which retained the LMP1 cytoplasmic tail but has lost the constitutive activity of LMP1 and needs to be activated by the CD40 ligand. We show that LMP1 signaling can completely substitute CD40 signaling in B cells, leading to normal B-cell development, activation, and immune responses including class-switch recombination, germinal center formation, and somatic hypermutation. In addition, the LMP1-signaling domain has a unique property in that it can induce class-switch recombination to IgG1 independent of cytokines. Thus, our data indicate that LMP1 has evolved to imitate T-helper cell function allowing activation, proliferation, and differentiation of EBV-infected B cells independent of T cells.