Dynamic Interferometry Lithography on a TiO 2

International audienceSolar electricity is one of the most promising renewable energy resources. However, the ratio module's cost/energy produced remains a major issue for classical photovoltaic energy. Many technologies have been developed to solve this problem, by using micro-or nanostructuring on the solar cell or on the module. These kinds of structuring are often used as antireflection and light-trapping tools. In the meantime, other solar technologies are considered, such as concentration photovoltaic modules. This article presents a module combining both approaches, that is, nanostructures and concentration, in order to increase the module's profitability. Sol-gel derived TiO 2 diffraction gratings, made by dynamic interferometric lithography, are added on the top of the glass cover to deflect unused light onto the solar cell, increasing the module efficiency

Neutrophils are required for both the sensitization and elicitation phase of contact hypersensitivity

Allergic contact dermatitis and its animal model, contact hypersensitivity (CHS), are T cell-mediated inflammatory skin diseases induced by contact allergens. Though numerous cellular and molecular players are known, the mechanism of chemical-induced sensitization remains poorly understood. Here, we identify neutrophils as crucial players in the sensitization phase of CHS. Genetic deficiency of neutrophils caused by myeloid-specific deletion of Mcl-1 or antibody-mediated depletion of neutrophils before sensitization abrogated the CHS response. Neutrophil deficiency reduced contact allergen-induced cytokine production, gelatinase release, and reactive oxygen species production in naive mice. Mast cell deficiency inhibited neutrophil accumulation at the site of sensitization. In turn, neutrophils were required for contact allergen-induced release of further neutrophil-attracting chemokines, migration of DCs to the draining lymph nodes, and priming of allergen-specific T cells. Lymph node cells from mice sensitized in the absence of neutrophils failed to transfer sensitization to naive recipients. Furthermore, no CHS response could be induced when neutrophils were depleted before elicitation or when normally sensitized lymph node cells were transferred to neutrophil-deficient recipients, indicating an additional role for neutrophils in the elicitation phase. Collectively, our data identify neutrophils to be critically involved in both the sensitization and elicitation phase of CHS

Oral Probiotic Control Skin Inflammation by Acting on Both Effector and Regulatory T Cells

Probiotics are believed to alleviate allergic and inflammatory skin disorders, but their impact on pathogenic effector T cells remains poorly documented. Here we show that oral treatment with the probiotic bacteria L. casei (DN-114 001) alone alleviates antigen-specific skin inflammation mediated by either protein-specific CD4+ T cells or hapten-specific CD8+ T cells. In the model of CD8+ T cell-mediated skin inflammation, which reproduces allergic contact dermatitis in human, inhibition of skin inflammation by L. casei is not due to impaired priming of hapten-specific IFNγ-producing cytolytic CD8+ effector T cells. Alternatively, L. casei treatment reduces the recruitment of CD8+ effector T cells into the skin during the elicitation (i.e. symptomatic) phase of CHS. Inhibition of skin inflammation by L. casei requires MHC class II-restricted CD4+ T cells but not CD1d-restricted NK-T cells. L casei treatment enhanced the frequency of FoxP3+ Treg in the skin and increased the production of IL-10 by CD4+CD25+ regulatory T cells in skin draining lymph nodes of hapten-sensitized mice. These data demonstrate that orally administered L. casei (DN-114 001) efficiently alleviate T cell-mediated skin inflammation without causing immune suppression, via mechanisms that include control of CD8+ effector T cells and involve regulatory CD4+ T cells. L. casei (DN-114 001) may thus represent a probiotic of potential interest for immunomodulation of T cell-mediated allergic skin diseases in human

T-cell recognition of chemicals, protein allergens and drugs: towards the development of in vitro assays

Chemicals can elicit T-cell-mediated diseases such as allergic contact dermatitis and adverse drug reactions. Therefore, testing of chemicals, drugs and protein allergens for hazard identification and risk assessment is essential in regulatory toxicology. The seventh amendment of the EU Cosmetics Directive now prohibits the testing of cosmetic ingredients in mice, guinea pigs and other animal species to assess their sensitizing potential. In addition, the EU Chemicals Directive REACh requires the retesting of more than 30,000 chemicals for different toxicological endpoints, including sensitization, requiring vast numbers of animals. Therefore, alternative methods are urgently needed to eventually replace animal testing. Here, we summarize the outcome of an expert meeting in Rome on 7 November 2009 on the development of T-cell-based in vitro assays as tools in immunotoxicology to identify hazardous chemicals and drugs. In addition, we provide an overview of the development of the field over the last two decades

7th Drug hypersensitivity meeting: part two

No abstract availabl

Elaboration de couches minces nanocomposites sur support souple par voie sol-gel.

International audienceElaboration de couches minces nanocomposites sur support souple par voie sol-gel

Cinetique et voie de dégradation photocatalytique d'acides aminés- Influence du pH et du flux lumineux

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