[Progesterone - regulator of T-lymphocytes cytotoxicity].

Progesterone plays important the role in the regulation of the immune system during pregnancy. We examined the effect of progesterone on the cytotoxic activity of T-lymphocytes in a model system Jurkat cells. Jurkat cells were stimulated with 50 µg/ml of phytohemaglutinin A (PHA) at 370C for 5 minutes. Then, PHA was removed by centrifugation, the cells were washed and cultured for 24 hours alone or with progesterone (added to the incubation medium of Jurkat cells at a concentration of 0.07 and 0.7 µl. Determined value of The parameters of mitochondrial membrane potential (by flow cytometry) and parameters of mitochondrial oxidative metabolism (the rate of generation of superoxide and peroxide radicals and activity of mitochondrial superoxide dismutase, catalase, glutatinperoxidase, the degree of nitrosylation of mitochondrial electron-transport proteins (by method of electron paramagnetic resonance and spectrophotometry) were determined. It was identified the lowering effect of high dose of progesterone (0.7µl) on the value of mitochondrial membrane potential (balancing percentage of cells with high and low values of mitochondrial potential and decreased intensity of oxidative stress in mitogen - activated Jurkat cells, which supports inhibition of their proliferation and differentiation activity.

ß2-adrenergic regulation of T lymphocites function (in vitro study).

The aim of our study was to establish the influence of ß2AR agonists and antagonists on Th1/Th2 subpopulation balance in intact and activated CD4+ T lymphocyte. Jurkat leukemic T cell line was used as a model for studying T cell activation conditions under the influence of ß2AR ligands. As follows from the results of our studies, after the influence of ß2AR agonist isoproterenol on intact Jurkat cells expression of IL-2 was not changed in comparison to control level. Under the PHA-stimulation level of IL-2 production in Jurkat cells increased significantly; isoproterenol caused decrease level of IL-2 expression in the PHA-stimulated Jurkat cells. Adding of ß2AR antagonist propranolol to the Jurkat cells pre-incubated with isoproterenol didn't change expression of IL-2. ß2AR antagonist propranolol induced slight increase of IL-2 expression in PHA-stimulated Jurkat cells pre-incubated with isoproterenol. Neither isoproterenol nor propranolol didn't change intensity of IL-10 expression in intact Jurkat cells. In the PHA-stimulated Jurkat cells level of IL-10 production decreased in comparison to control level. Isoproterenol induced sharp intensification of IL-10 expression in these cells. Propranolol prevented increase of IL-10 expression in the PHA-stimulated Jurkat cells pre-incubated with ß2AR agonist. It was concluded that ß2ARs in dose-dependent manner regulate cytokine profile in intact and mitogen activated CD4+ T lymphocyte and by this way induce dose-dependent alterations of lymphocyte proliferation and immune response. This indicated existence of a link among immune response and sympathetic nervous system activity.

[The role of neuroendocrine mediators in regulatory activity of T-cells].

The aim of the study was to establish the role of some neuroendocrine mediators (agonists and antagonists of ß-adrenergic receptors, progesterone) in regulating T-cells activity. Studies conducted on the culture of leukemiatransformed T-cells (Jurkat cells) (DSMZ-Deutshe Sammulung von Mikroorganismen und Zellkulturen (Germany)). Jurkat Cells (4 x 105 cells/ml) stimulated with 50 µg/ml fitogemaglutinin A (PHA) at 370С for 5 minutes and then incubated for 24 hours alone, or together with ß- adrenergic receptors agonist izopretonolom (at dose of 10-5 M, 10-6 M), an antagonist, propranolol (dose of 10-5 M, 10-6 M) and progesterone (dose 0,07 µl, 0,7 µl) added to the incubation medium. The viability of Jurkat cells was determined by MTT test. It was shown that ß-adlenoretseptors agonist, izoprotenol didn't affect the activity of mitochondrial dehydrogenases in intact and contributed to their low activation (12%) in the mitogen-activated Jurkat cells. ß-adrenergic receptors antagonist, propranolol, promotes a significant reduction in activity of mitochondrial dehydrogenases, and hence the viability of both intact (40-60%) and mitogen stimulated Jurkat cells (20-40%). Viability of intact Jurkat cells didn't change, and dose-dependently increased in PHA-stimulated Jurkat cells during progesterone exposure. It was concluded that viability of the T-cells and hence their functional activity is largely sensitive to the influence of the ß-adrenoceptor antagonists and progesterone. These data should be considered in the clinical application of appropriate drugs.

[Cell death in Jurkat cells induced by oxygen/nitrogen stress].

The maintenance of balance between lymphocyte proliferation and lymphocyte death is extremely important for normal functioning of the immune system. Considering essential role of nitrogen and oxygen radicals in functioning of immune competent cells, we studied the mechanisms of cell death induced by nitrogen/oxygen stress on the model of Jurkat cell line. We have observed that hyperproduction of reactive oxygen in Jurkat cells incubated with hydrogen peroxide contributes to the activation of membrane peroxidation, to a decrease in the intensity of apoptosis and its replacement by more severe mechanism of cell death - necrosis, which is obviously conditioned by a dramatic decrease in the intensity of energogenesis in mitochondria. In cells incubated with sodium nitroprusside moderate NO-induced inhibition of electron transport in oxidative chain and mitochondrial energogenesis and intensification of oxidative stress in Jurkat cells is accompanied with the activation of the cell death mechanisms- both apoptosis and necrosis.

[Pharmacological activity of dihydroflavonol glycoside isolated from the plant Eupatorium micranthum Less].

The aim of the work was the investigation of pharmacological activity of unique dihydroflavonol glycoside, micranthoside, extracted from the leaves Eupatorium micranthum Less. introduced into Georgia. Mature human T-cell leukemia cell lines (Jurkat) were analyzed in the study under the modeled oxidative stress. For modelling of oxidative stress 30% hydrogen peroxide (H(2)O(2)) (Sigma) (100 microM) was added to Jurkat cell incubation suspension with subsequent incubation for 24, 48 h. Under the effect of H(2)O(2) there was significant elevation of superoxide and peroxyl radical levels, as well as free NO levels, and reduced antioxidant enzyme SOD activity. It was shown that dihydroflavonol glycoside, micranthoside, extragated from Eupatorium micranthum Less., has marked antioxidant properties, it inhibits hyperproduction of reactive oxygen species, and protects cells against oxidative damage, stimulates cell proliferation and inhibits necrosis in cell line.

[Plaferon lb as a protector of radioinducible disorder].

As it is known, p-53-dependent apoptosis is the cause of the radiosensitive cells' rapid death during the first ours after gamma-irradiation. It is considered, that short time suppression of the function of p-53 may decrease injury of normal tissue. The aim of our study was the determination of the effectiveness and possible mechanisms of radioprotective features of plaferon LB. It was found that plaferon LB provides correction of content and function of nitric oxide in hepatocytes during gamma-irradiation and that may be induced by its antioxidant capabilities. By the correction of oxidative metabolism plaferon LB decreases intensity of postradiation alterations. The restriction of intensification of nitric oxide synthesis after irradiation also results in decreasing of iNOS expression. Plaferon LB induces reduction of oxidative stress in the organism, also provides NO-modulatory activity. Increase of proapoptotic activity of p-53 is due to NO-stimulated DNA-dependent protein kinase and p-38 mitogen activated protein kinase. It may be concluded that during gamma-irradiation the preliminary influence of plaferon LB provides prevention of hyperproduction of nitric oxide and by this way promotes suppression of NO-inducible activation of p-53-induced apoptosis.

[Cytogenetic effects of irradiation in the kidney epithelial cells of monkeys and the possible use of these data for evaluating the level of chromosome aberrations in the kidneys of people exposed to irradiation]. / Tsitogeneticheskie éffekty oblucheniia v épitelial'nykh kletkakh pochek obez'ian i vozmozhnosti ispol'zovaniia étikh dannykh dlia otsenki urovnia aberratsii khromosom v pochkakh u lits, podvergshikhsia oblucheniiu.

Data are presented on somatic radiation-induced mutagenesis in epithelial kidney cells of monkeys. Chromosome aberrations in kidney cells of monkeys can serve as an index for the evaluation of human kidney state in the course of radiotherapy.

[Tetraploidy in the epithelial cells of monkey kidneys subjected to exposure to various radiation dosages in vitro and in vivo. III]. / Tetraploidiia v épitelial'nykh kletkakh pochek obez'ian, podverg-nutykh vozdeistviiu raznykh doz radiatsii in vitro, in vivo. Soobshchenie III.

Tetraploidy was found in 3- and 5-day cultures of monkey kidney epithelial cells irradiated with various X-ray doses at G0. At the G0 stage the portion of simple and complex tetraploid cells was determined in the monkey kidney epithelium after the whole body 60Co gamma-irradiation, 620-660 R.

[Identification of monkey chromosomes by differential staining with Romanovsky--Giemza stain. III. Cercopithecus aethiops]. / Identifikatsiia khromosom ob'ezian metodom differentsial'nogo okrashivaniia rastvorom Romanovskogo--Gimza. Soobshchenie III. Cercopithecus aethiops.

The distribution of the G-bands in chromosomes of bone marrow cells of Cercopithecus aethiops was studied by means of differentail staining with the Romanovsky - Gimsa dye. All the homologous chromosome pairs were identified and morphometric parameters were detected. The comparison of C. aethiops karyotypes with those of Macacca mulatta has shown that they are different in numbers and in the character of banding pattern of the most chromosomes. Both species revealed 12 pairs of chromosomes similar in their morphology and parameters.

[Frequency of radiation-induced exchanges in simian marker chromosomes]. / Chastota indutsirovannykh radiatsiei obmenov v markernykh khromosomakh obeziian

The symmetric and asymmetric exchange frequencies of marked (nucleolus forming) chromosomes were studied in the lymphocytes and epithelial kidney cells irradiated by X-rays at Go, both in vivo and in vitro. Symmetric and asymmetric exchange frequencies were found to be equal. In both the types of Macaca mulatta cells, the exchange frequency in the long arm appeared to be higher than theoretically expected. The increased exchange in the long arm is thought to be due to a greater quantity of late replicating heterochromatin in it. The short arm of marked chromosome of epithelial kidney cells enters the exchange in accordance to its length in mitosis, but exchange number in the short arm chromosome in lymphocytes is lower than in epithelial cells. This difference is caused by different functioning of the nucleolus forming heterochromatin.