Antigen-Specific Mammary Inflammation Depends on the Production of IL-17A and IFN-γ by Bovine CD4+ T Lymphocytes

Intramammary infusion of the antigen used to sensitize cows by the systemic route induces a local inflammation associated with neutrophil recruitment. We hypothesize that this form of delayed type hypersensitivity, which may occur naturally during infections or could be induced intentionally by vaccination, can impact the outcome of mammary gland infections. We immunized cows with ovalbumin to identify immunological correlates of antigen-specific mammary inflammation. Intraluminal injection of ovalbumin induced a mastitis characterized by a prompt tissue reaction (increase in teat wall thickness) and an intense influx of leukocytes into milk of 10 responder cows out of 14 immunized animals. The magnitude of the local inflammatory reaction, assessed through milk leukocytosis, correlated with antibody titers, skin thickness test, and production of IL-17A and IFN-γ in a whole-blood antigen stimulation assay (WBA). The production of these two cytokines significantly correlated with the magnitude of the milk leukocytosis following the ovalbumin intramammary challenge. The IL-17A and IFN-γ production in the WBA was dependent on the presence of CD4+ cells in blood samples. In vitro stimulation of peripheral blood lymphocytes with ovalbumin followed by stimulation with PMA/ionomycin allowed the identification by flow cytometry of CD4+ T cells producing either IL-17A, IFN-γ, or both cytokines. The results indicate that the antigen-specific WBA, and specifically IL-17A and IFN-γ production by circulating CD4+ cells, can be used as a predictor of mammary hypersensitivity to protein antigens. This prompts further studies aiming at determining how Th17 and/or Th1 lymphocytes modulate the immune response of the mammary gland to infection.     

Are Binary Copper Sulfides/Selenides Really New and Promising Thermoelectric Materials?

Copper sulfides and copper selenides have recently been reported as new and promising low‐cost and environmentally friendly thermoelectric materials. Here, it is shown that these materials have actually been studied for more than 190 years and the absence of commercial thermoelectric modules based on them stems from some major intrinsic issues related to these chalcogenides. Further development of these semiconductors will require addressing and solving these problems before large scale utilization can be considered.     

Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papillomavirus

Antiviral activity has been demonstrated for different tannin-rich plant extracts. Since tannins of different classes and molecular weights are often found together in plant extracts and may differ in their antiviral activity, we have compared the effect against influenza A virus (IAV) of Hamamelis virginiana L. bark extract, fractions enriched in tannins of different molecular weights and individual tannins of defined structures, including pseudotannins. We demonstrate antiviral activity of the bark extract against different IAV strains, including the recently emerged H7N9, and show for the first time that a tannin-rich extract inhibits human papillomavirus (HPV) type 16 infection. As the best performing antiviral candidate, we identified a highly potent fraction against both IAV and HPV, enriched in high molecular weight condensed tannins by ultrafiltration, a simple, reproducible and easily upscalable method. This ultrafiltration concentrate and the bark extract inhibited early and, to a minor extent, later steps in the IAV life cycle and tannin-dependently inhibited HPV attachment. We observed interesting mechanistic differences between tannin structures: High molecular weight tannin containing extracts and tannic acid (1702 g/mol) inhibited both IAV receptor binding and neuraminidase activity. In contrast, low molecular weight compounds (<500 g/mol) such as gallic acid, epigallocatechin gallate or hamamelitannin inhibited neuraminidase but not hemagglutination. Average molecular weight of the compounds seemed to positively correlate with receptor binding (but not neuraminidase) inhibition. In general, neuraminidase inhibition seemed to contribute little to the antiviral activity. Importantly, antiviral use of the ultrafiltration fraction enriched in high molecular weight condensed tannins and, to a lesser extent, the unfractionated bark extract was preferable over individual isolated compounds. These results are of interest for developing and improving plant-based antivirals.     

Growth variations and heritabilities of teak CSO-derived families and provenances planted in two humid tropical sites

Sixteen families derived from a clonal seed orchard (CSO) and 10 “provenances” (Prov) of teak (Tectona grandis) were tested in two different sites to be compared with respect to their growth performances. Both sites were located in Sabah, East Malaysia, under 2,500 mm of annual rainfall and no distinct dry season. The land in Taliwas was flat but prone to waterlogging. In Luasong, the soil was more hilly, acidic, and less fertile, though deeper. Nearly 9 years after planting, the two classes of genetic entries showed significant differences for height (P?=?0.0002) and diameter at breast height (DBH) and volume (P?<?0.0001) for the two sites combined. The superiority of the CSO families compared with the Prov class was more obvious in Luasong with averages of 18.0 vs 15.2 m (+18.6 %) for height, 18.1 vs 15.1 cm (+20.2 %) for DBH, and 0.179 vs 0.107 m³ for individual tree volume (+67.9 %), as against 17.4 vs 15.7 m (+11.2 %), 19.1 vs 16.8 cm (+13.5 %), and 0.176 vs 0.126 m³ (+40.3 %), respectively, in Taliwas. The CSO families were also more prone to site interaction for height (P?=?0.004) and, to a lesser extent, for volume (P?=?0.017) than the “Prov” (P?=?0.030 and P?=?0.057, respectively). Narrow-sense heritabilities estimated for the 16 CSO families across the two sites were lower for DBH (0.17) and volume (0.23) than for height (0.38). Type B genetic correlations suggested also higher site × families interactions for height (r _B?=?0.28).     

L’Observatoire hommes–milieux international Tessékéré (OHMi) : un outil de recherche pour étudier la complexité des écosystèmes arides du Sahel

In the Sahelian zone, the drought phenomenon, combined with anthropic factors (monoculture, bush fires, defect or deficit of manure, overgrazing, etc.), has seriously affected ecological great balances, involving a degradation of the natural resources as well as a fall in agricultural productions, pointing to a process of desertification. To face these challenges, in the course of the 8th ordinary session of the conference of the Heads of States of the African Union held in January 2007 in Addis Ababa (Ethiopia), 11 countries adopted the Panafrican project called the Green Great Wall (GGW). The total objective of the GGW is to contribute i) to the fight against the desert's advance, ii) to the development of the Saharan-Sahelian zones toward a durable management of the natural resources, and iii) to the fight against poverty. It deals with the construction of a set of zones of afforestation crossing the whole African continent in the long term (7000 km of which are in the west). Even if some decisions in the launching phase the GGW must be taken quickly, one cannot do without investment in interdisciplinary research. In particular, associating fundamental research and applied research will allow us to ensure the success in the medium and long term of such a large-scale reforestation project. Research segmented in compartmentalized knowledge fields needed to get adequate tools, among which OHMi Tessékéré, initiated by INNEE (Centre national de la recherche scientifique [CNRS]), in partnership with UCAD, constitutes an example. This suitable scientific tool, capable of action flexibility, of self-financing capacity, anchored in civil society, ready to implement a pragmatic and local interdisciplinarity founded currently on the concept of socio-ecological system (SES), is the one we chose to conduct our studies on the Ferlo arid ecosystems.