Differential expression of THELPER 1 cytokines upon antigen stimulation predicts ex vivo proliferative potential and cytokine production of virus-specific T cells following re-stimulation.

INTRODUCTION: Cytomegalovirus (CMV) and human adenovirus (ADV) infections are causes of morbidity after stem cell transplantation. Antigen (Ag)-specific T cells are essential for the control of viral infections. However, in vivo expansion potential of T-cell subpopulations is hardly predictable in humans. Furthermore, ex vivo identification of human T cells with repopulating capacity for adoptive T-cell transfer has been difficult. METHODS: We analyzed Ag-specific T-cell populations, subdivided according to the expression of different THELPER- 1 (Th1) cytokines. Isolation by flow cytometry was based on interferon-gamma (IFN)-γ, interleukin (IL)-2, or tumor necrosis factor-alpha (TNF-α) secretion of T cells after ex vivo stimulation with the Ags hexon (for ADV) and pp65 (for CMV). Isolated T cells were expanded and examined for functional characteristics, expansion/differentiation potential, and naïve, effector memory, central memory, and late effector phenotypes. RESULTS: Isolation based on IFN-γ production provides a T-cell population with a mixture of early, central memory, and effector memory T cells, high expansion potential, and effective cytokine production. Selection of T cells with Ag-specific expression of IL-2 or TNF-α, however, results in a T-cell population with reduced proliferation and lower effector potential after expansion. CONCLUSION: We conclude that the exclusive secretion of IFN-γ in the human antiviral T-cell responses preferentially leads to higher repopulation capacities of antiviral T cells, compared to IL-2 or TNF-α secreting T-cell populations.

An Fc-optimized CD133 antibody for induction of NK cell reactivity against myeloid leukemia.

Antibody-dependent cellular cytotoxicity (ADCC) of natural killer (NK) cells largely contributes to the success of monoclonal antibody (mAb) treatment in cancer. As no antibodies are clinically available for immunotherapy of myeloid leukemias (MLs), we aimed to develop an Fc-optimized CD133 mAb for induction of NK ADCC against MLs. When comparing different available CD133 mAbs, no difference was observed with regard to binding to primary chronic myeloid leukemia cells. However, clone 293C3 recognized acute myeloid leukemia (AML) cells in a substantially higher percentage of patient cases and was thus chosen to generate chimeric mAbs with either wild-type Fc part (293C3-WT) or a variant containing amino-acid exchanges (S239D/I332E) to enhance affinity to CD16 on NK cells (293C3-SDIE). In vitro, treatment with 293C3-SDIE significantly enhanced activation, degranulation and lysis of primary CD133-positive AML cells by allogeneic and autologous NK cells as compared with its wild-type counterpart. In line with the observed lower expression levels of CD133 on healthy cells compared with malignant hematopoietic cells, 293C3-SDIE caused no relevant toxicity towards committed hematopoietic progenitor cells. In a NOD.Cg-PrkdcscidIL2rgtmWjl/Sz xenotransplantation model, 293C3-SDIE facilitated elimination of patient AML cells by human NK cells. Thus, 293C3-SDIE constitutes an attractive immunotherapeutic compound, in particular for elimination of minimal residual disease in the context of allogeneic stem cell transplantation in AML.

Within-target illusory correlations and the formation of context-dependent attitudes.

Two experiments explored the formation of context-dependent attitudes about a single social target. One such mechanism for the development of differential attitudes toward a target in different contexts is illusory correlation formation. It was proposed that within-target illusory correlations (i.e., perceiving unwarranted associations between salient target behaviors and distinctive domains in which the target is observed) can result in biased evaluations of a social target in different domains (e.g., home vs. work). When memory-based (vs. on-line) judgments were induced, perceivers formed context-dependent attitudes for both group (Experiment 1) and individual (Experiment 2) targets. These findings are consistent with theories regarding multiply categorizable attitude objects. Further, they suggest that some apparent discrepancies between attitudes and behavior may reflect holding multiple context-dependent attitudes about social targets.

Evidence for the role of proteinases in uremic catabolism.

Enhanced muscle protein breakdown has been demonstrated in acutely uremic rats by numerous authors. In order to investigate the pathogenetic role of skeletal muscle proteinases leupeptin, a low-molecular weight proteinase inhibitor, was administered intraperitoneally to acutely uremic rats. Twenty-four hours after bilateral nephrectomy, leupeptin-treated animals displayed significantly lowered serum urea levels (-32%), as compared to untreated uremic rats. As a sign of muscle protein breakdown, plasma levels of Nt-methylhistidine, an indicator of myofibrillar protein degradation, were also decreased (-35%) in the uremic animals treated with leupeptin as compared to untreated uremic rats. Finally, leupeptin treatment resulted in a significant inhibition of the myofibrillar alkaline proteinase activity, a proteinase which has been related to various catabolic conditions. These findings suggest that the increased muscle protein breakdown in uremia is caused by enhanced activity of muscular proteinases and that anti-proteolytic agents display favourable effects on the enhanced protein degradation observed in acute uremia.

[Punt-driver with jaundice - case 1/2014]. / Stocherkahnfahrer mit Ikterus - Fall 1/2014.

HISTORY AND ADMISSION FINDINGS: A 30-year-old student, who worked part-time as a punt-driver, was admitted to the hospital with fever up to 39.5 °C, severe pain in in his lower extremity and the lower back, nausea and jaundice. INVESTIGATIONS: Physical examination showed jaundice of skin and sclera as well as conjunctivitis of both eyes. Blood examination results indicated high levels of bilirubin (mostly conjugated), C-reactive protein and creatinine. There were no pathological findings in the ultrasound examination except of discrete splenomegaly. Serology revealed Leptospira IgM antibodies. DIAGNOSIS, TREATMENT AND COURSE: The patient was diagnosed with leptospirosis and was treated with intravenous ceftriaxon, intravenous rehydration and symptomatic analgesia. Upon this treatment, the liver and kidney function recovered and the patient could be discharged from the hospital in a good general condition. CONCLUSIONS: Leptospirosis is a zoonosis which is mainly transmitted by urine of infected animals (predominantly rodents). In this case, the disease was presumably transmitted during the patients work as a professional punt-driver on the Neckar River. The course of the disease is mostly mild with flu-like symptoms, but there are also serious courses with live-threatening complications such as liver or kidney failure and an associated high mortality rate.

Inhibition of nitric oxide synthesis augments centrally induced sympathetic coronary vasoconstriction in cats.

The principal effect of sympathetic activation on the coronary circulation is an alpha-adrenergic coronary vasoconstriction in the presence of beta-receptor blockade. Secondary effects include vasodilation due to beta-adrenoceptor stimulation and alpha 2-mediated release of endothelium-derived relaxing factor (EDRF) from the coronary vascular endothelium. We hypothesized that blockade of nitric oxide synthesis (nitro-L-arginine methyl ester, L-NAME) would augment coronary vasoconstriction to sympathetic stimulation as a result of a decrease in alpha 2-mediated EDRF release. In chloralose-anesthetized cats, hypothalamic stimulation produced increases in coronary vascular resistance [maximum 26 +/- 9% (SE)] and arterial pressure (41 +/- 7%) and a decrease in coronary blood flow velocity (15 +/- 6%). L-NAME (3 mg/kg iv) increased baseline arterial pressure from 69 +/- to 92 +/- 7 mmHg (P < 0.05). After L-NAME, a greater increase in coronary vascular resistance (55 +/- 20%, P < 0.05), a decrease in coronary blood flow velocity (24 +/- 7%, P < 0.05), and a similar pressor response (34 +/- 7%) were observed in response to hypothalamic stimulation. L-Arginine reversed the effect of L-NAME on coronary vasoconstriction to hypothalamic stimulation. Similar increases in arterial pressure (from 73 +/- 3 to 91 +/- 5 mmHg, P < 0.05) with vasopressin (0.01-0.05 U/min) failed to enhance coronary vasoconstriction to activation in anterior hypothalamus. We conclude that inhibition of EDRF synthesis augments centrally induced sympathetic coronary vasoconstriction in the cat.

Hypoxia regulates the cAMP- and Ca2+/calmodulin signaling systems in PC12 cells.

Hypoxic/ischemic trauma is a primary factor in the pathology of various disease states. Yet, very little is known about the molecular mechanisms involved in cellular responses and adaptations to hypoxia. As a means of identifying intracellular signaling systems that are regulated in response to hypoxia, the effects of acute and chronic hypoxia on the activity of protein kinase A (PKA) and Ca2+/CaM-dependent protein kinase II (CaMK-II) were evaluated in rat pheochromocytoma (PC12) cells. Chronic (> 6 hr), but not acute exposure to hypoxia (5% O2) significantly decreased both PKA enzyme activity and immunoreactivity compared to control levels. This effect was not due to hypoxia-induced alterations in cell number or viability. Similarly, chronic hypoxia significantly decreased CaMK-II enzyme activity and protein levels in PC12 cells. These data demonstrate that down-regulation of the cAMP and Ca2+/CaM-signaling systems is a mechanism by which PC12 cells adapt to long-term hypoxia.

Evidence for reduced catabolism by the antiglucocorticoid RU 38486 in acutely uremic rats.

Previous studies suggested that increased blood levels of, or increased tissue sensitivity to, glucocorticoids may contribute to catabolism in acute uremia. To examine this possibility we determined urea nitrogen (urea-N) appearance, plasma levels of Nt-methylhistidine and the activity of the alkaline myofibrillar proteinase in acutely uremic rats with and without treatment with RU 38486, a selective antiglucocorticoid. Forty-eight hours after bilateral nephrectomy, the rats had markedly elevated serum levels of urea-N, creatinine, potassium and phosphorus. In uremic rats receiving RU 38486, comparable levels of serum creatinine were found, but the serum levels of urea-N (221 +/- 4 vs. 259 +/- 5 mg/dl) and phosphorus (6.5 +/- 0.3 vs. 8.5 +/- 0.4 mmol/l) were significantly decreased as compared to uremic animals without RU 38486. In comparison to sham-operated rats, urea-N appearance (net urea production) was increased by 56% 48 h after bilateral nephrectomy. This increment was almost completely reversed in uremic animals receiving the antiglucocorticoid. In untreated uremic rats, plasma levels of Nt-methylhistidine were 10.3 +/- 0.9 microgram/dl, whereas the administration of RU 38486 caused a significant decline in the levels of this amino acid (7.6 +/- 0.5 microgram/dl). This reduction in Nt-methylhistidine was associated with a concomitant decrease of myofibrillar proteinase activity in muscle tissue homogenates. Compared to sham-operated animals, this proteinase activity was increased by 30% in uremic rats, but was normal in those given RU 38486. Taken together, these data support the view that in acute uremia accelerated ureagenesis occurs, while enhanced muscle protein breakdown, owing to an increment in myofibrillar proteinase activity, provides the necessary amino acid precursors.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of muscle protein degradation by leupeptin in acutely uremic rats.

Enhanced muscle protein breakdown has been demonstrated in acutely uremic rats by numerous authors. These findings have been used to explain the clinical signs of muscle wasting and enhanced urea-N appearance, frequently observed in patients suffering from uremia. In order to investigate whether inhibition of skeletal muscle proteinases would have a favourable effect on the extent of muscle protein degradation, leupeptin, a low-molecular-weight proteinase inhibitor, was administered intraperitoneally to acutely uremic rats. 24 h after bilateral nephrectomy, leupeptin-treated animals displayed significantly lowered serum urea levels (-32%), and hence decreased urea-N appearances (-39%) as compared to untreated uremic rats. As a sign of muscle protein breakdown, plasma levels of Nt-methylhistidine, an indicator of myofibrillar protein degradation, were also decreased (-35%) in the uremic animals treated with leupeptin as compared to untreated uremic rats. Finally, leupeptin treatment resulted in a significant inhibition of the myofibrillar alkaline proteinase activity, a proteinase which has been related to various catabolic conditions. These findings suggest that the increased muscle protein breakdown in uremia is caused by enhanced activity of muscular proteinases and that antiproteolytic agents display favourable effects on the enhanced protein degradation observed in acute uremia.