Effects of Microvesicles Derived from NK Cells Stimulated with IL-1ß on the Phenotype and Functional Activity of Endothelial Cells.

Microvesicles (MVs) are plasma extracellular vesicles ranging from 100 (150) to 1000 nm in diameter. These are generally produced by different cells through their vital activity and are a source of various protein and non-protein molecules. It is assumed that MVs can mediate intercellular communication and modulate cell functions. The interaction between natural killer cells (NK cells) and endothelial cells underlies multiple pathological conditions. The ability of MVs derived from NK cells to influence the functional state of endothelial cells in inflammatory conditions has yet to be studied well. In this regard, we aimed to study the effects of MVs derived from NK cells of the NK-92 cell line stimulated with IL-1ß on the phenotype, caspase activity, proliferation and migration of endothelial cells of the EA.hy926 cell line. Endothelial cells were cultured with MVs derived from cells of the NK-92 cell line after their stimulation with IL-1ß. Using flow cytometry, we evaluated changes in the expression of endothelial cell surface molecules and endothelial cell death. We evaluated the effect of MVs derived from stimulated NK cells on the proliferative and migratory activity of endothelial cells, as well as the activation of caspase-3 and caspase-9 therein. It was established that the incubation of endothelial cells with MVs derived from cells of the NK-92 cell line stimulated with IL-1ß and with MVs derived from unstimulated NK cells, leads to the decrease in the proliferative activity of endothelial cells, appearance of the pan leukocyte marker CD45 on them, caspase-3 activation and partial endothelial cell death, and reduced CD105 expression. However, compared with MVs derived from unstimulated NK cells, a more pronounced effect of MVs derived from cells of the NK-92 cell line stimulated with IL-1ß was found in relation to the decrease in the endothelial cell migratory activity and the intensity of the CD54 molecule expression on them. The functional activity of MVs is therefore mediated by the conditions they are produced under, as well as their internal contents.

Does stress-induced release of interleukin-1 cause liver injury?

It is well established that repeated immobilization stress (RIS) is induced by increased levels of cytokines and the emergence of lesions in the liver. Our data prove that interleukin-1 (IL-1) causes liver lesions in stressed Wistar rats. In essence, the relationship between IL-1 and stress-induced liver injury is based on three findings: (1) IL-1ß treatment causes liver inflammation, consisting of infiltrating monocytes and the appearance of necrosis by increasing lipid peroxidation and protein carbonylation. Positive correlations between the content of heptane-soluble diene conjugates and an area of necrosis, as well as between content carbonylated proteins and an area of necrosis, were found after injection of IL-1ß to unstressed rats. (2) RIS is accompanied by increased levels of circulating IL-1ß and corticosterone. In the liver, stress causes the emergence of foci of necrosis with perivascular and lobular infiltration of mononuclear cells as well as increased free radical oxidation. Moreover, there were observed down-regulations of cytochrome P450 (CYP)-dependent enzymes, CYP1A1 activities, and decreased CYP1A1 mRNA content. Positive correlations between the level of circulating IL-1ß and necrosis areas, as well as between circulating IL-1ß and the content of heptane-soluble diene conjugates, were observed in stressed rats. In addition, the positive correlation between necrosis foci and heptane-soluble diene conjugates was revealed after stress cessation. (3) Use of the IL-1 receptor antagonist Anakinra at a dose of 2 µg/kg to treat the effects of stress prevents infiltration of mononuclear cells and reduces the level of free radical oxidation as well as necrosis of lesions. As a result, blocking IL-1 receptors with an antagonist significantly rescues stress-induced liver injury, suggesting that IL-1 might be involve in the cascade of liver injury that initiated by sustained stress.

Monoclonal antibody to an endogenous bufadienolide, marinobufagenin, reverses preeclampsia-induced Na/K-ATPase inhibition and lowers blood pressure in NaCl-sensitive hypertension.

BACKGROUND: Levels of marinobufagenin (MBG), an endogenous bufadienolide Na/K-ATPase (NKA) inhibitor, increase in preeclampsia and in NaCl-sensitive hypertension. METHODS: We tested a 3E9 monoclonal anti-MBG antibody (mAb) for the ability to lower blood pressure (BP) in NaCl-sensitive hypertension and to reverse the preeclampsia-induced inhibition of erythrocyte NKA. Measurements of MBG were performed via immunoassay based on 4G4 anti-MBG mAb. RESULTS: In hypertensive Dahl-S rats, intraperitoneal administration of 50 microg/kg 3E9 mAb lowered BP by 32 mmHg and activated the Na/K-pump in the thoracic aorta by 51%. NaCl supplementation of pregnant rats (n = 16) produced a 37 mmHg increase in BP, a 3.5-fold rise in MBG excretion, and a 25% inhibition of the Na/K-pump in the thoracic aorta, compared with pregnant rats on a normal NaCl intake. In eight pregnant hypertensive rats, 3E9 mAb reduced the BP (21 mmHg) and restored the vascular Na/K-pump. In 14 patients with preeclampsia (mean BP, 126 +/- 3 mmHg; 26.9 +/- 1.4 years; gestational age, 37 +/- 0.8 weeks), plasma MBG was increased three-fold and erythrocyte NKA was inhibited compared with that of 12 normotensive pregnant women (mean BP, 71 +/- 3 mmHg) (1.5 +/- 0.1 vs. 3.1 +/- 0.2 micromol Pi/ml/h, respectively; P < 0.01). Ex-vivo 3E9 mAb restored NKA activity in erythrocytes from patients with preeclampsia. As compared with 3E9 mAb, Digibind, an affinity-purified antidigoxin antibody, was less active with respect to lowering BP in both hypertensive models and to restoration of NKA from erythrocytes from patients with preeclampsia. CONCLUSION: Anti-MBG mAbs may be a useful tool in studies of MBG in vitro and in vivo and may offer treatment of preeclampsia.

Immunomodulating and anti-tumor action of extracts of several mushrooms.

Aqueous extracts from fruit bodies and mycelia of various higher Basidiomycetes were studied in search for reliable biological effects. In vitro and in vivo experiments were conducted. The results showed that the aqueous extracts demonstrated various types of marked biological actions: an increased production of reactive oxygen forms by neutrophil cells of human peripheral blood; a significant mitogenic activity in a wide range of concentrations; stimulation on production of inflammatory cytokines interleukine 1-beta and interleukine-8 by peripheral blood cells; a decrease in both average tumor size in mice with transplanted melanoma B16 and a manifestation of tumorous intoxication; and a prolongation in the survival rate of such mice.

Biological Activity of Peptide SCV-07 Against Murine Tuberculosis.

SCV-07 (gamma-glutamyl-tryptophan) is a new immunomodulatory compound that was developed and patented both for composition and immunomodulatory use. SCV-07 was shown to have a broad spectrum of immunostimulatory activities both in vitro and in vivo. In the present study we investigated the biological activity of SCV-07 in a murine model of experimental tuberculosis (TB) induced with M. bovis-bovinus 8 strain. Therapy with SCV-07 at doses of 0.01, 0.1, and 1 &mgr;g/kg (5 daily injections) decreased the lung damage index compared to untreated controls and to those treated with isoniazid alone. The growth of M. bovis-bovinus 8 in spleen culture was decreased. Cytokine studies showed that on the 24th day after the treatment with SCV-07 the production of IL-2 was restored to the level seen in uninfected animals. Proliferative responses for both thymic and spleen cells were nearly restored to the responses observed in uninfected animals. IFN-gamma production by both thymic and spleen cells, as well as its circulating levels in serum, was increased by the SCV-07 treatment. Concurrently, IL-4 production was decreased in the same cell types and the serum. These changes suggest that SCV-07 is stimulating a shift of T helper cells to a Th1-like immune response. SCV-07 treatment also stimulated the macrophage functions, which had been decreased by tuberculosis infection and isoniazid therapy, with an improved phagocytosis activity of peritoneal macrophage. The obtained results suggest that SCV-07 treatment increases the efficacy of anti-tuberculosis therapy as well as the strength of the immune response. Thus, SCV-07 is a prospective immunomodulator for a complex therapy of TB.