Distinct pathways of antigen uptake and intracellular routing in CD4 and CD8 T cell activation

The mechanisms that allow antigen-presenting cells (APCs) to selectively present extracellular antigen to CD8+ effector T cells (cross-presentation) or to CD4+ T helper cells are not fully resolved. We demonstrated that APCs use distinct endocytosis mechanisms to simultaneously introduce soluble antigen into separate intracellular compartments, which were dedicated to presentation to CD8+ or CD4+ T cells. Specifically, the mannose receptor supplied an early endosomal compartment distinct from lysosomes, which was committed to cross-presentation. These findings imply that antigen does not require intracellular diversion to access the cross-presentation pathway, because it can enter the pathway already during endocytosis.     

Video-rate far-field optical nanoscopy dissects synaptic vesicle movement

We present video-rate (28 frames per second) far-field optical imaging with a focal spot size of 62 nanometers in living cells. Fluorescently labeled synaptic vesicles inside the axons of cultured neurons were recorded with stimulated emission depletion (STED) microscopy in a 2.5-micrometer by 1.8-micrometer field of view. By reducing the cross-sectional area of the focal spot by about a factor of 18 below the diffraction limit (260 nanometers), STED allowed us to map and describe the vesicle mobility within the highly confined space of synaptic boutons. Although restricted within boutons, the vesicle movement was substantially faster in nonbouton areas, consistent with the observation that a sizable vesicle pool continuously transits through the axons. Our study demonstrates the emerging ability of optical microscopy to investigate intracellular physiological processes on the nanoscale in real time.     

Hijacking of host cell IKK signalosomes by the transforming parasite Theileria

Parasites have evolved a plethora of mechanisms to ensure their propagation and evade antagonistic host responses. The intracellular protozoan parasite Theileria is the only eukaryote known to induce uncontrolled host cell proliferation. Survival of Theileria-transformed leukocytes depends strictly on constitutive nuclear factor kappa B (NF-kappaB) activity. We found that this was mediated by recruitment of the multisubunit IkappaB kinase (IKK) into large, activated foci on the parasite surface. IKK signalosome assembly was specific for the transforming schizont stage of the parasite and was down-regulated upon differentiation into the nontransforming merozoite stage. Our findings provide insights into IKK activation and how pathogens subvert host-cell signaling pathways.     

Assessing genetic diversity of Polish wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis>) varieties using microsatellite markers

Fifty-three wheat cultivars have been genotyped using 24 SSR (simple sequence repeat) markers in order to evaluate genetic similarities among Polish wheats, i.e. 53 spring and winter cultivars; ‘Chinese Spring’ was taken as reference. ll but one SSR marker allowed to identify DNA polymorphisms, giving in total 166 alleles (including nulls), from 3 to 13 alleles per marker with mean of 7.22. Based on marker data, genetic similarities were calculated and a dendrogram was created. ‘Spring’ cultivars were less diverse than winter ones, showing the biggest similarity to ‘Chinese Spring’. Four sister cultivars (Nutka, Tonacja, Zyta and Sukces), formed a cluster of very similar materials, of which Zyta and Sukces had the highest similarity indices. Parental lines Jubilatka and SMH 2182 were more distant from each other (genetic similarity of 0.227). It was possible to differentiate all the wheats using only four SSR markers: Xgwm186, Xgwm389, Xgwm459 and Xgwm577.     

Alterations of vitamin C, total phenolics, and antioxidant capacity as affected by processing tomatoes to different products

This study was conducted to investigate the antioxidant vitamin C, the polyphenol content, and the hydrophilic antioxidant capacity of tomato juice, baked tomatoes, tomato sauce, and tomato soup. During the production of tomato juice and during the preparation of the other tomato products, samples were taken after different times, respectively, after each particular production step. High-performance liquid chromatography was used to determine the content of vitamin C. The total phenolics content was analyzed spectrophotometrically by using the Folin-Ciocalteu method. The hydrophilic antioxidant capacity was measured by using three different methods: the Trolox equivalent antioxidant capacity assay, the ferric reducing antioxidant power test, and the photochemiluminescence assay. The vitamin C contents of the tomato products decreased during the thermal processing of tomatoes. In contrast, the total phenolics concentration and the water soluble antioxidant capacity increased.     

Effects of Biofertilizers on Mn and Zn Acquisition and Growth of Higher Plants: A Rhizobox Experiment

Plant disease resistance and susceptibility are greatly influenced by the availability of micronutrients, particularly manganese (Mn) and zinc (Zn). Take-all disease of wheat, caused by a strong Mn oxidizing fungus (Gaeumannomyces graminis var tritici, Ggt), results in a lack of availability of Mn to plants and increases disease severity in wheat. Three commercial Trichoderma harzianum (Vitalin T-50, BioHealth®-WSG, and BioHealth®-G) and one Bacillus subtilis (Vitalin SP-11) were investigated individually and in combination (Vitalin T-50 and Vitalin SP-11) for growth promotion and Mn/Zn uptake of take-all infected wheat in a rhizobox experiment under greenhouse conditions. Inoculation with Trichoderma and Bacillus biofertilizers did not increase the shoot dry weight and shoot to root ratio, whilst shoot length was significantly increased with Vitalin T-50 and Biohealth-G treatments in the final harvest. Biofertilizers inoculation that significantly (P < 0.05) enhanced root surface area and root dry weight were Vitalin T-50, BioHelath-G and combination of Vitalin (T-50 + SP-11). The bulk soil pH was not influenced by biofertilizer inoculation, whereas rhizosphere and rhizoplane soil pH were significantly reduced (0.3 – 0.4 pH scale) in Vitalin (T-50 + SP-11) and BioHealth-G treatments and to a lesser extent by Vitalin T-50 inoculation. Manganese uptake in shoots of wheat exhibited no significant differences among the biofertilizer treatments. On the contrary, Zn uptake was significantly higher in Vitalin T-50, Vitalin (T-50 + SP-11), BioHealth-G, and BioHealth-WSG (47, 64, 44, and 45%, respectively) inoculated plants. Therefore, Vitalin T-50 and Biohealth-G showed better performance in improving plant growth and Zn uptake.     

Überprüfung eines Schätzverfahrens zur Ermittlung von Kennwerten der Wasserbindung anhand der Labordatenbank des Niedersächsischen Bodeninformationssystems

Testing a method for estimating water retention parameters using the laboratory database of the Lower Saxony Soil Information System The validity of the method used for estimating field capacity (pF > 1.8), plant available water (pF 1.8 – 4.2), air capacity (pF < 1.8), and total pore volume from soil texture, packing density (bulk density + 0.009 % clay) and humus content described by the Arbeitsgruppe Bodenkunde (1982) was checked on the basis of 1693 pF curves of the laboratory database of the Lower Saxony Soil Information System (NIBIS). The positive and negative corrections for humus content applied in this method to the above parameters are clearly too small. Use of tables for estimating the pore volume of humus-free soils leads to overestimation. It will only be possible to work out an alternative method applicable to all classes of soils when the database has been extended.     

Enrichment of N2 and Ar in the atmosphere of CO2-consuming soils

The phenomenon of unexplained N₂Ar-enrichment in soil air is quite frequently to be encountered in soil air studies on anthropogenically influenced sites. In the present study two anthropogenic deposits and a calcareous fluvisol were investigated for their soil air composition. While in the alkaline deposits extreme enrichments of N₂ and Ar (N₂ + Ar: up to 99%, v/v) were found as persistent site characteristics, the fluvisol showed only slight (about 1%, v/v) transient N₂/Ar-enrichments in summer. All sites, which did not show substantial vertical seepage percolation, exhibited enhanced CO₂-solubility-either due to strong calcite precipitation or dissolution. So, it was concluded that intensive continuous depletion of CO₂ was responsible for the subsequent convective influx of atmospheric air. From the results obtained it was concluded that an encasement of the concerned soil volume rather impermeable to gas transport as well as intense dissolution of CO₂ in the pore water are prerequisites for substantial N₂/Ar-enrichments in soil air.     

Effects of environment, disease progress, plant height and heading date on the detection of QTLs for resistance to Fusarium head blight in an European winter wheat cross

In order to characterise quantitative trait loci (QTLs) for Type I and Type II resistance against Fusarium head blight (FHB) in wheat, a population of recombinant inbred lines derived from the cross Cansas (moderately resistant)/Ritmo (susceptible) was evaluated in spray-inoculated field trials over three seasons. Map-based QTL analysis across environments revealed seven QTLs on chromosomes 1BS, 1DS, 3B, 3DL, 5BL, 7BS and 7AL (QFhs.whs-1B, QFhs.whs-1D, QFhs.whs-3B, QFhs.whs-3D, QFhs.whs-5B, QFhs.whs-7A, QFhs.whs-7B) associated with FHB resistance. They accounted for 56% of the phenotypic variance. QFhs.whs-1D primarily appeared to be involved in resistance to fungal penetration, whereas the other QTLs mainly contributed to resistance to fungal spread. FHB resistance was significantly correlated with plant height (PH) and heading date (HD). Including all single environments, corresponding overlaps of QTLs for FHB resistance and QTLs for PH/HD occurred at six loci, among them two consistently detected QTLs, QFhs.whs-5B and QFhs.whs-7A. When significant effects of PH and HD on FHB resistance were eliminated by covariance analysis, a second QTL analysis revealed possible escape mechanisms for the majority of the coincidental loci.