Time-Dependent Regulation of IL-2R α-Chain (CD25) Expression by TCR Signal Strength and IL-2-Induced STAT5 Signaling in Activated Human Blood T Lymphocytes.

The expression of the IL-2R α-chain (IL-2Rα) is regulated at the transcriptional level via TCR- and IL-2R-signaling. The question is how to precede in time the activation signals to induce the IL-2Rα expression in native primary T cells. By comparing the effects of selective drugs on the dynamics of CD25 expression during the mitogen stimulation of human peripheral blood lymphocytes, we identified distinct Src- and JAK-dependent stages of IL-2Rα upregulation. PP2, a selective inhibitor of TCR-associated Src kinase, prevents CD25 expression at initial stages of T cell activation, prior to the cell growth. This early IL-2Rα upregulation underlies the T cell competence and the IL-2 responsiveness. We found that the activated with "weak" mitogen, the population of blood lymphocytes has some pool of competent CD25+ cells bearing a high affinity IL-2R. A distinct pattern of IL-2R signaling in resting and competent T lymphocytes has been shown. Based on the inhibitory effect of WHI-P131, a selective drug of JAK3 kinase activity, we concluded that in quiescent primary T lymphocytes, the constitutive STAT3 and the IL-2-induced prolonged STAT5 activity (assayed by tyrosine phosphorylation) is mostly JAK3-independent. In competent T cells, in the presence of IL-2 JAK3/STAT5 pathway is switched to maintain the higher and sustained IL-2Rα expression as well as cell growth and proliferation. We believe that understanding the temporal coordination of antigen- and cytokine-evoked signals in primary T cells may be useful for improving immunotherapeutic strategies

Development and Modeling of an Onion Harvester with an Automated Separation System

One of the most important problems during the implementation of any technology is to reduce labor costs, energy, and resource conservation while increasing the yield of cultivated crops and, as a result, reducing the cost of production. Despite a significant amount of scientific research devoted to the problem of energy and resource conservation in the cultivation and harvesting of agricultural crops and the development of mechanization tools that ensure the high-quality performance of technological operations, there remain issues that have not been fully resolved to date. In addition, not all the results of known theoretical and experimental studies can be directly applied to intensify the process of harvesting root crops since the quality indicators of marketable products depend on the type and technological parameters of the separating working bodies. This article presents the design of a rod elevator with an adjustable angle of inclination of the web, which reduces damage to commercial products of root crops and bulbs with maximum completeness of separation. A laboratory facility has been developed to substantiate the design and technological parameters of a separating system with an adjustable web inclination angle. Based on the results of theoretical and experimental studies, a machine for harvesting onions with an adjustable blade inclination angle has been developed, which provides an increase in the quality indicators of onion harvesting at optimal values of the parameters: (1) translational speed of movement of the rod elevator with an adjustable web inclination angle of 1.7 m/s with a 98.4% completeness of separation and 1.7% damage to the bulbs; (2) translational speed of the movement of the machine for harvesting root crops and onions 1.0 m/s with a 98.5% separation completeness and 1.1% damage to the bulbs; (3) digging depth of the digging plowshare equal to 0.02 m, with an onion heap separation completeness of more than 98% and product damage of less than 1.4%. The results of theoretical and experimental studies of a rod elevator to substantiate the design and technological parameters during its interaction with a heap of onion are presented. Basic design and technological parameters of the studied rod elevator are substantiated, namely, the distance S1 of the movement of the rod of the actuators, the angle a1 of the longitudinal inclination of the surface of the rod elevator relative to the horizon, and differential equations of motion of the onion-sowing pile element on the surface of the rod elevator with an adjustable angle of inclination of the web

Charge carrier properties of single-crystal CVD diamond up to 473 K

The drift behavior of charge carriers, generated by �-particles of a reference 241Am-source, in electronic grade, single crystal chemical vapor deposition (scCVD) diamond was investigated by the transient current technique (TCT) from room temperature up to ≈ 473 K. Furthermore, the �-spectroscopic behavior was analyzed in terms of charge collection and spectroscopic resolution for the same temperature range. All conducted measurements revealed complete charge collection up to the maximum temperature. The electron–hole-pair creation energies were derived from the TCT as well as from the spectroscopic measurements. The herein presented results imply that high temperature �-spectroscopy with diamond-based semiconductor solid state detectors, using presently available scCVD sensor substrates, is feasible at least up to 473 K. Only at the highest applied temperature, the conducted TCT measurements showed distorted signal traces, indicating a uniform positive space charge built-up.ISSN:0168-9002ISSN:1872-957

Stimulation with non-mitogenic PHA and IL-2 leads to long-term CD25 expression and proliferation in human blood T lymphocytes.

<p>(A) The representative histograms of one experiment on PBL from one donor are shown. PBL were not stimulated (CTR) or stimulated with 0.7 μg/ml (0.7PHA), or 10 μg/ml (10PHA) PHA, or 200 U/ml IL-2 (IL-2) for 48 h. In the same experiment, PBL were preincubated in culture medium with 0.7 μg/ml PHA and 80 μM WHI-P131 (WHI) or 1.0 μM PP2 for 24 h prior to IL-2 stimulation, or drugs were added simultaneously with 0.7 μg/ml PHA for 24 h and thereafter IL-2 was added for the next 24 h. Additional Y-axis is 4 decades logarithmic scale. (B) CD25 expression in resting PBL in response to 0.7 μg/ml PHA (2) and 10 μg/ml PHA (8), or in competent PBL in response to IL-2 in the absence (3) or presence of WHI-P131 (4) or PP2 (5), or in response to IL-2 in PBL preactivated with 0.7 μM PHA in the presence of WHI-P131 (6) or PP2 (7). Summary data of independent experiments on PBL from different donors are shown as mean + SEM (n = 4, p˂0.05). (C) Proliferation of resting PBL in response to 0.7 μg/ml PHA (2) and 10 μg/ml PHA (6, 7), or competent PBL in response to IL-2 in the absence (3) or presence of PP2 (4) or WHI-P131 (5). Bars represent the number of cells in (S+G2+M) phases of cell cycle at 48h after PBL stimulation. Summary data of independent experiments on PBL from different donors is shown as mean + SEM (n = 4, p˂0.05).</p

PHA stimulation leads to long-term CD25 expression in human blood T lymphocytes.

<p>(A) The representative histograms of nine experiments on PBL from different donors are shown. PBL were cultivated with 10 μg/ml PHA in the absence or presence of 80 μM WHI-P131 (WHI) or 1.0 μM PP2 and after 5, 24 or 48 h were analyzed by flow cytometry. The dot plots have been obtained with Win MDI Version 2.8. In order to identify the axis labels, the additional vertical axis is shown in the upper row of histograms. Y-axis is 4 decades logarithmic scale. <b>1, 2 –</b>The gate was chosen considering the cell size increase during blasttransformation: 1- CTR—control, non-stimulated PBL, 2 –after 48 h of culture with 10 μg/ml PHA. X-axis–forward scatter (FSC), Y-axis–side scatter (SSC). (B) Time-course of CD25+ expression in PHA-induced PBL. 1 –Total number of CD25+ cells, 2—large CD25+ cells, 3—small CD25+ cells. (C) WHI-P131- and PP2-inibitable portions of CD25+ cells in PHA-stimulated PBL. Summary of independent experiments is presented as mean ±SEM (n = 9, p˂0.05). In each experiment, when analyzing the PHA-induced CD25 expression changes, the background CD25 expression in resting cells (CTR) was subtracted. Summary data are presented as mean ± SEM (n = 10, p˂0.05).</p

The inhibitory effect of WHI-P131 and PP2 on CD25 expression in PHA-stimulated human blood T lymphocytes.

<p>(A) The PP2-inhibitable expression of CD25 is timely associated with the initial stages of PBL activation. Cells were cultivated with 10 μg/ml PHA without or with 80 μM WHI-P131 (WHI) or 1.0 μM PP2 for 19 h (middle row) or cells were cultivated with 10 μg/ml PHA for 19 h and thereafter WHI-P131 or PP2 were added for the next 21 h (bottom row). Additional Y-axis is 4 decades logarithmic scale. Representative data on PBL from one donor are shown. (B) Summary data of four independent experiments are shown as mean + SEM (n = 4, p˂0.05). (C) The inhibitory effects of WHI-P131 (WHI) and PP2 on CD25 expression are additive. Cells were cultivated with 10 μg/ml PHA without or with WHI-P131 (WHI, 20 and 50 μM), or PP2 (0.4 and 0.8 μM), or WHI-P131 (20 μM) and PP2 (0.4 μM) were given simultaneously for 24 h. Summary of independent experiments are presented as mean + SEM (n = 4). ⃰, <i>p<</i>0.05. CTR—control, non-stimulated PBL.</p

The growth, proliferation and viability of human blood T lymphocytes, stimulated with PHA or IL-2 in the absence or presence of WHI-P131 and PP2 for 48 h.

<p>The growth, proliferation and viability of human blood T lymphocytes, stimulated with PHA or IL-2 in the absence or presence of WHI-P131 and PP2 for 48 h.</p

Plasma exposure of different tungsten grades with plasma accelerators under ITER-relevant conditions

This paper presents the results of tungsten irradiation experiments performed with three plasma facilities: the QSPA Kh-50 quasi-steady-state plasma accelerator, the PPA pulsed plasma gun and the magneto-plasma compressor. Targets made of different kinds of tungsten (sintered, rolled and deformed) were irradiated with powerful plasma streams at heat fluxes relevant to edge-localized modes in ITER. The irradiated targets were analyzed and two different meshes of cracks were identified. It has been shown that the major cracks do not depend on the tungsten grade. This has been attributed to ductile-to-brittle transition effects. Meshes of inter-granular micro-cracks were detected for energy loads above the melting threshold and these were probably caused by the re-solidification process. The blister-like and cellular-like structures were observed on sample surfaces exposed to helium and hydrogen plasmas