[ROLE OF PURINERGIC RECEPTORS IN IMMUNE RESPONSE].

Purine receptors are located on immune and somatic cells of animal and human organisms. Summation of signals from purine and TOLL-like receptors takes place on the level of inflammasome formation and results in summation of the first and second signals of innate immunity. The first signal--from PAMPs (pathogen associated molecular patterns), the second--from DAMPs (danger associated molecular patterns). Adenosine triphosphate (ATP) is the most studied DAMP. ATP connects with purine receptors which include P2 (P2X7 receptors are the best described), that results in opening of channels of these receptors and transit of ATP into the cell. In parallel exit of K⁺ from cells and entrance of Ca²âº and Na⁺ into the cells is observed, that is associated with activation of the immune competent cell. Damaged cells dying via necrosis or apoptosis are the source of extracellular ATP, as well as activated immunocytes. Signals from P2 and TOLL-like receptors are summarized in effectors of immune response, and activation of P2 receptors in lymphocytes makes a contribution into activation of cells, mediated by T-cell receptor. Negative side of purine receptor activation is a stimulating effect on proliferation and metastasis of malignant cells. The practical output of knowledge on functioning of purine receptors for clinical immunology is the application of agonists and antagonists of purine receptors, as well as explanation of effect of immune modulators from the position of launch of K⁺/Na⁺-pump; resulting in prolonged activation of immune competent cells.

[Sulfated polysaccharides of brown seaweeds--ligands of toll-like receptors].

The interaction of sulfated polysaccharides--fucoidans from brown seaweeds Laminaria japonica, Laminaria cichorioides and Fucus evanescens with Toll-like receptors (TLRs) expressed on membranes of embryonic human kidney epithelial cells (HEK293-null, HEK293-TLR2/CD14, HEK293-hTLR4/CD14-MD2 and HEK293-hTLR2/6) was investigated. In vitro fucoidans specifically interacted with TLR-2, TLR-4, and the heterodimer TLR-2/6 resultated in activation of transcription nuclear factor NF-kappaB. Analysis of composition the hydrolyzed fucoidan from F. evanescens was carried out by gas-liquid chromatography and chromatography-mass spectrometry. Results indicated the absence of 3-3-hydroxytetradecanoic acid (3-OHC14), the basic component of lipopolysaccharides in the preparation. Thus, the obtained results suggested that fucoidans from brown seaweeds possessing immunotropic activity are independent ligands for TLRs, and are able to induce genetically determined biochemical processes of protection organisms against pathogenic microorganisms.

[Novel type of vaccine with a combination of Toll like receptor agonists--TLR 1/2, 4, 5/6, 9].

AIM: Proof of therapeutic efficacy of a novel type of vaccine with a combination of natural Toll like receptor agonists (TLR) 1/2, 4, 5/6, 9 in infectious and noninfectious human pathology. MATERIALS AND METHODS: Immunovac-VP-4 vaccine, containing antigens of opportunistic microorganisms that are TLR 1/2, 4, 5/6, 9 ligands, was used for experiments and clinical trials. RESULTS: Immunovac-VP-4 activates innate immunity by inducing maturation of dendritic cells with expression of costimulating molecules on their membrane (CD40+, CD80+, CD86+), terminal differentiation molecules--CD83+ and antigen-presenting molecules (MHC class I and II); activates proinflammatory (TNFalpha, IL-6) and regulatory (IL-12, INFgamma) cytokine synthesis that programs T-lymphocyte differentiation by Th1 pathway; increases cytotoxic activity of natural killer cells, inhibits melanoma B16 growth and Lewis lung carcinoma metastasis. Therapeutic effect of Immunovac-VP-4 was evident regardless of pathology by a significant decrease of quantity and severity of recidives, improvement of all clinical parameters, reduction of quantity of administered pharmaceutical preparations including antibiotics and glucocorticosteroids. The rate of intercurrent acute respiratory viral illnesses and their bacterial complications decreased. Immunovac-VP-4 therapy modified course of illness from severe into milder forms. Positive therapeutic effect was 69.2 - 100%. CONCLUSION: High therapeutic effect of vaccine therapy is based on innate immunity activation by combining TLR agonists. Immunovac-VP-4 contains an optimal combination of natural TLR agonists that ensure high therapeutic effect in various nosological forms of infectious and noninfectious human pathology.

[Production of cytokines by murine bone marrow dendritic cells in vitro mediated by sulfated polysaccharides obtained from sea brown algae].

AIM: To assess in vitro cytokine production by murine bone marrow dendritic cells (DC) matured under the effect of sulfated polysaccharides--fucoidanes from sea brown algae Laminaria cichorioides and Laminaria japonica. MATERIALS AND METHODS: CBA line mice were used to obtain bone marrow origin precursors of DC. Isolation and study of chemical composition and structure of fucoidanes were performed using modern research methods. Expression of surface markers was determined by flow cytometry (FACS-analysis) using monoclonal antibodies to respective antigens. Levels of cytokine production were measured by t-ELISA using kits manufactured by Biosource (Belgium). RESULTS: I was determined that fucoidans induce maturation of DC that was evident by expression of terminal differentiation marker CD83, activation marker CD38, enhanced expression of costimulating CD86, antigen-presenting MHC II and adhesive CD11c molecules. Fucoidanes stimulate DC to produce proinflammatory (TNF-alpha, IL-6, IL-1beta) and regulatory (IL-12) cytokines. Fucoidanes enhance expression of TLR-2 and TLR-4 but do not influence on expression of TLR-9. CONCLUSION: It was shown that fucoidanes from sea brown algae L. cichorioides and L. japonica activate innate immunity system that is evident by enhanced expression of surface molecules associated with DC maturation and increased production of proinflammatory and regulatory cytokines by DC. Enhanced expression of TLR-2 and TLR-4 allows to suppose that studied fucoidanes could have anti-infective effect in vivo.

Effect of recombinant heat shock protein 70 of mycobacterial origin on cytotoxic activity and immunophenotype of human peripheral blood mononuclear leukocytes.

Recombinant heat shock protein of mycobacterial origin with a molecular weight 70 kDa in concentration 0.1 microg/ml in vitro activates cytotoxic activity of mononuclear lymphocytes from peripheral blood of healthy donors against K-562 human erythroblastic leukemia cells sensitive to natural killers. In other concentrations (1.0 microg/ml and 10 microg/ml) this heat shock protein did not significantly affect functional activity of mononuclear leukocytes. Expression of CD4, CD25, CD16 and CD56 on membrane of mononuclear leukocytes was also studied.

[Modulation of antigen-presenting functions in peritoneal macrophages and changes in production of several cytokines in mice caused by purified staphylococcal toxoid].

With adaptive transfer method it has been shown that immunomodulator purified staphylococcal toxoid (PST) changed (stimulate or suppress) antigen-presenting function (APF) of mice peritoneal macrophages (MF) in vivo. This phenomenon was registered during assessment of ability of peritoneal MF to present heterologous (with regard to PST) antigen--sheep erythrocytes (SE). Modulation vector depended from time interval between PST and SE inoculations. Inoculation of PST 1.5 h before SE resulted in stimulation of APF. When SE were inoculated to donor mice 24 h after PST, suppression of APF was developed. Suppression of APF was observed along with suppression of proinflammatory cytokines (IL-1beta, IL-6, TNF-alpha) as well as B-lymphocytes growth factor (IL-4). When cytokine profile was assessed 4 h after PST injection, the suppression of synthesis of these cytokines was not observed. Production of IL-12 increased in 9-12 times in 4 and 24 h after PST injection.

[Immunomodulators of microbial origin enhance cytotoxicity of human mononuclear leukocytes and reduce metastatic progression of Lewis lung carcinoma in mice].

Effect of immunomodulators for microbial origin on innate immunity and antitumor system was continued to study. Immunomodificator Immunovac VP-4, purified staphylococcal toxoid and glucosaminyl muramyl dipeptide (GMDP) equally enhanced cytotoxicity of mononuclear leukocytes of peripheral blood of healthy donors. Index of cytotoxicity was 2.78, 2.77 and 2.70 respectively. Reduced metastatic progression of Lewis lung carcinoma in mice was observed after Immunovac VP-4 and GMDP administration. Effectiveness was seen when preparations administered according to schedules including their administration before implantation of the tumor. If preparations were administered number of metastases reduced in 4.4-5.6 times and size of metastases reduced in 7-10 times. Interplay between antitumor activity of studied immunomodulators and cytotoxic activity of NK-cells, which are base effectors of antitumor immune response, are discussed.

[Generation of dendrite cells and the use of immunomodulators of bacterial origin as cell differentiation inducers].

The generation of ripe dendrite cells (DC) of marrow origin was obtained with the use of the vaccine Immunovac-BN-4, an immunomodulator of microbial origin, as well as Klebsiella pneumoniae LPS and TNF-alpha, as ripening inducers. These inducers equally led to the ripening of DC. The generation of ripe DC was characterized by morphological, phenotypical and functional changes. The immunophenotype of cells altered from CD34+, CD38-, CD40-, CD80-, CD86-, MHC I-, MHC II-, F4/80- to CD34-, CD38+, CD40+, CD80+, MHC I+, MHC II+, F4/ 80(low). In parallel with the ripening of DC their phagocytic activity decreased. In culture medium with ripe DC the levels of such cytokines as IL-1b, IL-6, IL-12, IFN-gamma, TNF-alpha significantly increased and the production of IL-4 decreased. The content of IL-2 and IL-10 remained unchanged.

[Influence of dendrite cells, generated with the use of immunomodulators of microbial origin, on the proliferative and cytotoxic activity of lymphocytes].

The influence of ripe dendrite cells (DC) on the proliferative activity of mononuclear leukocytes and the cytotoxic activity of lymphocytes of syngenic mice was studied. As inducers of DC ripening, the combination of antigenic components incorporated into the vaccine "lmmunovac Bh-4", (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Staphylococcus aureus), as well as K. pneumoniae LPS and TNF-alpha, were used. This study demonstrated that DC activated with these preparations enhanced the proliferative activity of mononuclear leukocytes, the activity of Bh-4 being higher than that of K. pneumoniae LPS. The increase of proliferative activity was accompanied by a rise in the cytotovicity of mouse lymphocytes with respect to the NK-sensitive tumor line YAC-1 or Ehrlich tumor cells. The incubation of the lymphocytes with ripe DC (with the use of the preparations under study as ripening inducers), loaded with tumor antigens, made it possible to obtain cytotoxic lymphocytes having high cytotoxic activity with respect, mainly, to those tumor lines from which lysates for the treatment of DC had been produced. The activation of DC with bacterial immunomodulators led to an increase in the antigen-presenting function of these cells, to their higher capacity for regulating the differentiation of mononuclear leukocytes and for activating the cytotoxicity of natural killers.

[Activation of Langat virus infection in mice under the influence of Licopid]. / Aktivatsiia Langat virusnoi infektsii u myshei pod vliianiem Likopida.

The impact of Licopid and purified staphylococcal toxoid on the development of neurovirus infection caused by Langat virus was experimentally studied with mice as a model. The prophylactic (prior to infection) use of licopid was found to activate the infection. In the population of macrophages of different localization the proportion of cells with virus penetration and proliferation increased 5- to 11-fold under the influence of Licopid. The results obtain give evidence to conclude that immunomodulators should be used with caution as they show not only positive effects.

[Stress increases the population of splenic macrophages, permissive for Langat virus, in mice]. / Stress uvelichivaet u myshei subpopuliatsiiu permissivnykh dlia virusa Langat selezenovhnykh makrofagov.

As shown in experiments on BALB/c mice, stress caused by hypokinesia is associated with a 3- to 8-fold increase in the number of splenic macrophages, permissive to Langat virus. No changes in the proportion of T and B lymphocytes in the spleen of the animals occur under the influence of the stress. Simultaneously with an increase in the subpopulation of permissive splenic macrophages, the stressed mice have exhibited an increase in sensitivity to intraperitoneal infection with Langat virus.

Non-specific modulation of the immune response with liposomal meningococcal lipopolysaccharide: role of different cells and cytokines.

The immunomodulating action of Neisseria meningitidis lipopolysaccharide (LPS) incorporated into liposomes and the activation of different populations of immunocompetent cells or the secretion of cytokines were studied. LPS stimulated an anti-sheep red blood cell (SRBC) plaque-forming cell response in the spleen of mice after simultaneous injection of LPS and SRBC but if LPS was administered 3 days before the immunization with SRBC the response to SRBC was strongly suppressed. After the incorporation of LPS into liposomes the stimulation index was increased from 6 to 19 and the liposomal LPS did not suppress the immune response to SRBC. The incorporation of LPS into liposomes leads to enhancement of B-mitogenic properties of LPS, as liposomal LPS stimulated the proliferation of splenocytes in mice better than free LPS and has no influence on the thymocytes. The liposomal LPS induced more prolonged and significant accumulation of IgM-secreting cells in the spleen of mice in comparison with the free LPS. Liposomal LPS also induced more active accumulation of IFN-gamma in human peripheral blood mononuclear cells and less active accumulation of monokines, contributing to the realization of the toxic properties of endotoxin (IL-1 alpha, TNF-alpha, IL-6 and GM-CSF). These results demonstrated that the incorporation of N. meningitidis LPS into liposomes dramatically changed its immunomodulating activity. The data obtained are important for the construction of an adjuvant formulation for synthetic immunogens capable of inducing genetically unrestricted immune responses.