Lipophilic Prodrug of Methotrexate in the Membrane of Liposomes Promotes Their Uptake by Human Blood Phagocytes.

Previously, we showed that incorporation of methotrexate (MTX) in the form of a lipophilic prodrug (MTXDG) in 100-nm lipid bilayer liposomes of egg phosphatidylcholine can allow one to reduce toxicity and improve the antitumor efficiency of MTX in a mouse model of T-cell leukemic lymphoma. However, in our hemocompatibility tests in vitro, MTX liposomes caused complement (C) activation, obviously due to binding on the liposome surface and fragmentation of the C3 complement factor. In this work, we studied the interactions of MTX liposomes carrying stabilizing molecules phosphatidylinositol (PI), ganglioside GM1, or a lipid conjugate of N-carboxymethylated oligoglycine (CMG) in the bilayer with subpopulations of human blood leukocytes. Liposomes labeled with BODIPY-phosphatidylcholine were incubated with whole blood (30 min and 1 h, 37°C), blood cells were lysed with a hypotonic buffer, and the fluorescence of the liposomes bound but not internalized by the leukocytes was quenched by crystal violet. Cell suspensions were analyzed by flow cytometry. Incorporation of MTXDG dramatically enhanced the phagocytosis of liposomes of any composition by monocytes. Neutrophils consumed much less of the liposomes. Lymphocytes did not accumulate liposomes. The introduction of PI into MTX liposomes practically did not affect the specific consumption of liposomes by monocytes, while CMG was likely to increase the consumption rate regardless of the presence of MTXDG. The GM1 ganglioside presumably shielded MTX liposomes from phagocytosis by one of the monocyte populations and increased the efficiency of monocyte uptake by another population, probably one expressing C3b-binding receptors (C3b was detected on liposomes after incubation with blood plasma). MTX liposomes were shown to have different effects on TNF-α production by activated leukocytes, depending on the structure of the stabilizing molecule.

IFN-α, IFN-ß, and IFN-γ Have Different Effect on the Production of Proinflammatory Factors Deposited in Weibel-Palade Bodies of Endothelial Cells Infected with Herpes Simplex Virus Type 1.

We demonstrated similarities and differences in the effects of IFN-α and IFN-ß compared to IFN-γ on the production of factors deposited in the Weibel-Palade bodies in cultures of endothelial cells (intact and infected with herpes simplex virus 1). IFN-α and IFN-ß reduced the content of von Willebrand factor, endothelin-1, and soluble P-selectin and increased IL-8 concentration in the culture medium of human umbilical vein endothelial cells. IFN-γ reduced the content of all studied factors in the endothelial cell culture medium. Possible mechanisms of these effects are discussed.

[Human interferon modulates infected vascular endothelium function].

BACKGROUND: To study impact of interferon (IFN) alpha, beta and gamma on the Herpes simplex virus type 1 (HSV-1) infected endothelial cells functional activity related with participation in the inflammation development. MATERIALS AND METHODS: In the work endothelial cells isolated from umbilical vein were used. Intact and infected cultures were treated by interferon and in the dynamics of cultivation tested mediators in the cultural medium. RESULTS: All investigated interferons activated the production of IL-6. IFN alpha, beta activated the production of IL-8, while IFN gamma inhibited her. IFN alpha and gamma increased synthesis of nitrogen oxides and reduced the synthesis of endothelin-1, while IFN beta activated the production of endothelin-1. CONCLUSION: Infection of endothelial cells isolated from umbilical vein with HSV-1 does not alter the ability of interferon in modulating of proinflammatory cytokines, nitric oxide and endothelin-1 synthesis. It is obvious in the body modulation manifestations of innate immunity under the influence of exogenous interferon is implemented both intact and infected with HSV-1-vascular endothelium and nature modulation is determined by the type of IFN.

Effects of gold nanoparticles on erythrocyte hemolysis.

We studied hemolytic activity of gold nanoparticles added to the whole blood (ex vivo) and of nanoparticles coated and not coated with plasma components on erythrocytes in hypotonic medium (osmotic hemolysis) in vitro. Gold nanoparticles did not stimulate erythrocyte hemolysis after 4-h incubation with the whole blood ex vivo. Hemolysis tended to increase in the presence of small gold nanoparticles (5, 10, 20 nm) at the maximum concentration of 20 µM (by gold content) used in our study in comparison with the control. This tendency was detected during the 1st hour of the nanoparticles incubation with blood. Gold nanoparticles in the used concentrations (up to 20 µM of gold) coated with plasma components after preincubation with autologous plasma and nanoparticles without coating caused no osmotic hemolysis of erythrocytes in vitro.

[Adhesion molecules expressed in vascular endothelial cells in natural immunity against viral infections].

Cell adhesion molecules (CAM) expressed in vascular endothelium ensure integrity of the endothelial layer, recruitment and transmigration of leukocytes. Being receptors of many viruses, they play a role in immune control and infectious processes. Monoclonal anti-ICAM-1 antibodies enhance infection of primary human umbilical vein endothelial cell (HUVEC) cultures with HIV-1 due to incorporation into virions. IFN-gamma activates expression of ICAM-1 on HIV-infected HUVEC and thereby promotes binding of this molecule to complementary molecules on a greater number of sensitive cells, virion transfer onto them, and broad dissemination of the virus. Recombinant human IFN-alpha, IFN-beta and IFN-gamma influence (activate, inhibit) CAM shedding from HUVEC both intact and infected wit HSV-1. Activated shedding in the blood stream due to competition between soluble and endothelial CAM slows down recruitment and transmigration of leukocytes, i.e. regulates inflammation. CAM incorporated in microparticles can influence a wide spectrum of pathological processes Endothelial CAM may be a target for the delivery of pharmaceuticals for the treatment of vascular (including infectious) pathology.

[Changing the protective properties of the receptor domain of protective antigen anthrax exotoxin, depending on the orientation of the presentation on nanoparticles].

Polysterene particles bearing on its surface recombinant protein receptor domain of protective antigen anthrax exotoxin, exposed in different orientations have been constructed. Particles with exposed COOH region of receptor domain induced the highest protective immunity in mice anthrax model (95%). We revealed that immunization with these particles causes a specific induction of Th1-response, characterized by increased levels ofcytokine TNF-alpha and IL-2.

[The influence of oxidized fibrinogen on apoptosis of endothelial cells].

Oxidative stress plays an important role in cardio-vascular diseases and atherosclerosis. Fibrinogen (FB), plasma coagulation protein, is a risk factor of atherosclerosis. Importantly, it can be readily oxidized during oxidative stress and in pathological conditions. FB can promote angiogenesis by supporting migration and proliferation of endothelial cells. On the other hand, recent reports demonstrated cytotoxicity of oxidized fibrinogen (oxFB). Endothelial dysfunction plays a critical role in the atherosclerosis development, therefore it is important to understand the effect of oxFB on human endothelial cells (hEC), and the mechanism of the cell death. Here, we studied influence of oxFB on hEC during 24 h incubation in two conditions: (1) at low serum level (0.1%) and in the absence of growth factors ("starvation"); (2) in full medium (5% FBS) with growth factor supplement. Apoptosis was evaluated using analysis of nuclear morphology, phosphatidylserine externalization on hEC surface and caspase-3 activation. In starvation, we observed significant cell death via apoptosis. FB prevented starvation-induced cell death and caspase activation. Caspase activity in the presence of oxFB was 1.5 times higher as compared to FB, yet oxFB demonstrated significant cell protection during stress. Similarly, in optimal cultivation conditions FB decreased the rate of apoptosis by three times, while oxFB supported cell viability to the lesser extent. Thus, FB can protect hEC in stress conditions (in starvation); oxidative modification of FB diminishes its antiapoptotic properties.

[Differences in functional activity of cultivated human vascular endothelium received from different donors].

Endothelium of blood vessels in the organism is involved in carrying out numerous functions in normal and pathological processes. Development of the method of isolation and cultivation of endothelial cells has made it possible to model the processes occurring in vascular endothelium. Unlike continuous cell lines, research on primary cell cultures lead to wide variation in results. In this study, spontaneous production of markers characterizing functional activities of endothelium were compared in endothelium cultures derived from umbilical cords of 20 donors. It was found that, based on the production levels of all investigated markers after 3 hours of cell cultivation, these cultures can be divided into high- and low-producing. Analysis of cytokine profiles revealed that the level of spontaneous production of IL-1beta in these groups did not vary during cell cultivation up to 24 and 48 hours, whereas the levels of IL-6 and IL-8 production increased to 24 and 48 hours, and the difference between groups became leveled; the increase in production of TNFalpha occurred only in cultures of low-producing group. The increase in amounts of sP- and sE-selectin in cultural medium was observed only under cultivation of low-producing cultures, whereas the increase in sICAM-1 was noted under cultivation of highly-producing cultures; the increase of sPECAM-1 was revealed under cultivation of both highly- and low-producing cultures. So, the difference in the levels of this CAM between the groups remained. The levels of sVE-cadherin in cultural medium did not vary in the course of cell cultivation. The levels of nitrite reflecting the amount of NO were increased in cultural medium in all cultures, and the difference between the groups remained; concentration of endotelin-1 was increased, however the values of this marker in the cultural medium of several cultures were similar, therefore, it was not possible to create groups reflecting levels of its production. The levels of von Willebrand Factor were increased in cultural medium under cultivation of cultures of both groups, however the difference between the groups did not remain. The levels of matrix metalloproteinase-1 in cultural medium increased under cultivation of cell cultures. Hence, endothelial cultures from different donors differ in their ability to produce markers of functional activity, and reflect the features of cell donors. The results obtained allow modeling the processes occurring in vascular endothelium taking into account the individual characteristics of cultures, and suggest the possibility of a more thorough approach to evaluating the results obtained using primary endothelium cultures.

Effects of oxidized fibrinogen on the functions of blood cells, blood clotting, and rheology.

Oxidatively-modified fibrinogen induces platelet aggregation and potentiates ADP-induced platelet aggregation and production of active oxygen forms in zymosan-stimulated leukocytes. Fibrinogen induces IL-8 production in primary culture of endothelial cells from human umbilical vein; the oxidized form of fibrinogen is more active, similarly as during induction of the expression cell adhesion molecules (P-selectin and ICAM-1). Oxidized fibrinogen (10 and 20% oxidation degree) impairs microrheological properties of the blood, sharply reduces erythrocyte deformability, modifies blood viscosity, and reduces suspension stability of the blood. Oxidized fibrinogen modified blood clotting parameters and ADP-, ristocetin-, and collagen-induced platelet aggregation in whole blood. Oxidized fibrinogen disordered the formation of fibrin clot and blood clotting process. Platelet aggregation was activated in response to ADP, but not to ristocetin and collagen, the degree of activation increased in direct proportion to the degree of fibrinogen oxidation. This indicates the "dysregulatory" effect of oxidized fibrinogen on platelets. The formation of platelet complexes with polymorphonuclear leukocytes was intensified in the presence of oxidized fibrinogen; polymorphonuclear leukocyte luminol-dependent fluorescence intensity in the presence of platelets increased after incubation with oxidized fibrinogen in comparison with native fibrinogen. Hence, oxidized fibrinogen plays an important role in the development of atherosclerosis and its complications (thromboses).

Oxidized forms of fibrinogen induce expression of cell adhesion molecules by cultured endothelial cells from human blood vessels.

Oxidized forms of fibrinogen similarly to initial non-oxidized fibrinogen induced expression of P-selectin and ICAM-1 cell adhesion molecules in the cultured endothelial cells derived from human umbilical vein. The effect of oxidized fibrinogen on the expression of adhesion molecules was more pronounced. These data attest to more active participation of oxidized forms of fibrinogen into inflammation in the vascular wall, the first stage of atherogenesis.

[Angiogenesis and viral infections].

The review summarizes the results obtained from a study of the mechanisms responsible for angiogenesis during embryogenesis and adulthood in various abnormalities and in infections caused by hepatitis C virus and herpes simplex virus.

[Human blood vascular endothelial dysfunction in HIV infection].

The review presents information on the impact of human immunodeficiency virus (HIV) on the coagulative system in blood vessels and on the potential of endothelial infection in the organism and in the culture of endothelial cells derived in vitro from blood vessels of different tissues of the organism. It also discusses information on the mechanisms responsible for angiogenesis and apoptosis of the endothelial cells cultured in vitro under the influence of HIV and its proteins.

[Spectrum of cytokines produced by blood leukocytes in infection of herpes simplex virus, type 1]. / Spektr tsitokinov, produtsiruemykh leikotsitami krovi pri infektsii virusom prostogo gerpesa tipa 1.

Three types of reaction of human blood leucocytes to herpes simplex virus 1 (HSV-1) were detected. The first reaction type, i.e. production of IFN-alpha, IFN-gamma, IL-1beta, IL-6 and TNFalpha but not of IL-2 or IL-4, denotes the primary body reaction to an infectious agent. The second reaction type is related with infection of activated HSV-1 leucocytes and is accompanied by an inhibited production of IFN-gamma, IL-6 and IL-8, which is targeted at suppressing the antivirus cell mechanisms. The third reaction type is associated with production of IFN-alpha, IFN-gamma, IL-beta, IL-6 and TNFalpha by blood leucocytes affected by HSV-1-infected leucocytes.

Cow milk angiogenin induces cytokine production in human blood leukocytes.

Angiogenin isolated from cow milk induces the production of cytokines IL-1beta, IL-6, and TNF-alpha in human leukocytes; the level of production of each cytokine depends on the concentration of the preparation, and the dynamics of production depends on the time from the beginning of induction. Simultaneous treatment with angiogenin and phytohemagglutinin had an additive effect on the production of cytokines, the time of this effect manifestation being individual for each cytokine.

[Status of interferon in genital infections]. / Osobennosti interferonovogo statusa pri genital'nykh infektsiiakh.

The interferon status test characterizes the interferon (IFN) system function and the functional activity of IFN-producing cytokine cells. In contrast to the routine method, we used fetal calf (FCS) and autologous sera for evaluating the patients' leukocyte capacity to produce IFN-alpha and IFN-gamma. Blood samples from 30 women with genital infections caused by herpes simplex virus, cytomegalovirus, Chlamydia, and Ureaplasma were tested. Autologous sera of 40% patients inhibited and of 6.6% patients stimulated the production of IFN-gamma in comparison with FCS. All the data are statistically reliable. 20.3% autologous sera contained acid-labile IFN-alpha. These results can be used for more effective immunocorrective therapy.

[Production of cytokines from blood donor leukocytes]. / Produktsiia tsitokinov leikotsitami krovi donorov.

Cytokine production by donor blood leukocytes was investigated in vitro. LPS stimulation led to the production of IL-1 beta, IL-6, and TNF-alpha, if their spontaneous production was below the threshold sensitivity of the test method, and to a statistically negligible increase of production if spontaneous production was pronounced. The concentrations of cytokines produced depended on the nature of inductors and their doses. The inductor modulating effect can be used for stimulation and inhibition of cytokine production.

[New data on acid-labile alpha-interferon]. / Novoe o kislotlabil'nom alpha-interferone.

Reviews the information on the new concepts about the composition and properties of abnormal alpha-interferon-alpha-acid-labile interferon (alpha-ALI) detected in the blood of patients with AIDS, autoimmune, and other diseases. alpha-ALI includes alpha- and gamma-interferon which is responsible for acid lability. Increased content of serum alpha-ALI and its acid lability are poor prognostic signs in AIDS. A decrease in these values, concomitant with clinical improvement in some autoimmune diseases, indicates involvement of alpha-ALI in the pathogenesis of these diseases. Activating effect of gamma-interferon in vitro is demonstrated on different models, including HIV infection of human vascular endotheliocytes. The effect of alpha-ALI in patients is apparently determined by the ratio of its components alpha- and gamma-interferons.

[The production of inflammation mediators by mouse peritoneal cells under conditions of combined exposure to staphylococcal enterotoxin and lipopolysaccharide]. / Produktsiia mediatorov vospaleniia peritoneal'nymi kletkami myshei v usloviiakh sochetannogo vozdeistviia stafilokokkovogo énterotoksina i lipopolisakharida.

The influence of staphylococcal enterotoxin of type A (SEA) and enterobacterial lipopolysaccharide (LPS) on the production of tumor necrosis factor alpha (TNF alpha), gamma-interferon and active forms of oxygen by mouse peritoneal cells was studied. Both SEA and LPS, when injected to animals, produced stimulating influence on the oxygen metabolism of phagocytizing cells. The highest toxic doses of LPS induced the maximal generation of oxygen radicals. Under the conditions of the development of lethal toxic shock, i.e. after the combined injection of SEA and LPS, the synergic activation of oxygen metabolism was observed, which was also manifested by the pronounced production of TNF alpha and the increased synthesis of gamma-interferon.

[Interferon-inducing action of polysaccharide-containing biopolymers from ginseng root and cell culture]. / Interferonindutsiruiushchee deistvie polisakharidsoderzhashchikh biopolimerov iz kornia i kul'tury kletok zhen'shenia.

Induction of interferon (IF) and tumor necrosis factor (TNF) under the action of two polysaccharide preparations of ginseng i.e. panaxan-1 (from ginseng root) and panaxan-2 (from ginseng cell culture) was studied. Both the preparations induced production of TNF and IF in human leukocytes. By its properties and the typing results the induced IF proved to be gamma-IF. The preparation from the ginseng cell culture in the doses used had a higher IF inducing activity which could be explained by the difference in the polysaccharide composition of the preparations.