The Role of Intracellular Signaling Molecules in Macrophage Activation by Peat Humic Acids

Humic acids isolated by sodium pyrophosphate extraction from various types of peat activate macrophages in the classical proinflammatory pathway and stimulate nitric oxide production by these cells. This effect is mediated by activation of intracellular signaling pathways involving MAPK p38, PI3K, MEK 1/2 kinase, cAMP, and NF-κB via TLR-2 and TLR-4 receptors.

Influence of Humic Acids Isolated from Raised Bog Sphagnum Peat on Development of Th1/Th2 Immune Response

The course administration of humic acids isolated with sodium pyrophosphate from raised bog sphagnum peat reduces the parameters of a Th1-type immune response in C57BL/6 mice, the severity of an anaphylactic shock in outbred CD1 mice, and degranulation of mast cells after their immunization with ovalbumin. The addition of humic acids increases the stimulated production of IL-4, IL-10 and reduces the production of IL-2, IFNγ by peripheral blood mononuclear cells of healthy donors.

Anti-Allergic Properties of Humic Acids Isolated from Pine-Sphagnum-Cotton Sedge Peat

The course administration of humic acids isolated by the sodium pyrophosphate method from pine-sphagnum-cotton sedge peat reduced the general anaphylaxis reaction in mice and guinea pigs immunized with ovalbumin and decreased serum content of IgG1 and IgE in mice. The serum from mice treated with humic acids and sensitized with ovalbumin did not increase the rate of degranulation of mast cells isolated from intact Wistar rats in the presence of ovalbumin in comparison with the serum of control animals.

The Influence of Water-Soluble Polysaccharides of Crataegus sanguinea Pall. on Nitric Oxide Production by Macrophages

The in vitro addition of water-soluble polysaccharides isolated from the leaves of Crataegus sanguinea Pall. to culture of mouse peritoneal macrophages induced classical activation of antigen-presenting cells by increasing NO synthase activity and reducing arginase expression.

Excited states of modified oxygen-deficient centers and Si quantum dots in Gd-implanted silica glasses: emission dynamics and lifetime distributions

The emission centers and excited state characteristics of silica glasses implanted with Gd ions were studied by time-resolved pulsed cathodoluminescence. It was found that in the process of ion implantation, two types of new emission centers associated with Gd ions as well as Si quantum dots are formed in glassy silica. The distributions of excited states over the lifetime were found for both new centers and Si quantum dots. The nature of dispersion of the emission decay time was discussed in terms of structural disorder in the matrix. Thermal annealing and an increase in the ion fluence lead to the stimulation of the formation of Gd-related new centers and Si quantum dots. The micromechanisms for the formation of new Gd-related centers and two types of Si quantum dots were proposed on the basis of two scenarios for the introduction of Gd ions into the SiO₂ network: insertion of Gd into interstitial voids near oxygen-deficient centers and Gd  →  Si substitution with subsequent expulsion of Si atoms to the interstitial voids. New emission oxygen-deficient centers and quantum dots created by ion-beam technology in silica glasses are of interest for the development of new functional materials for photonics, and micro- and opto-electronics.

The Role of Intracellular Signaling Molecules in the Production of Granulocytic CSF Mononuclear Phagocytes in Stress and Cytostatic Influence

Under conditions of steady-state hemopoiesis, nuclear factor NF-κB, in contrast to MAP kinase p38, plays an important role in the maintenance of the initial level of secretory activity of monocytes. The increase in the production of G-CSF under stress conditions (10-h immobilization) is mainly regulated by the alternative p38MARK signaling pathway via activation of p38 synthesis. It was shown that under conditions of cytostatic-induced myelosuppression, the production of protein kinase p38 in cells decreases, and it, like NF-κB, is not the main one in the production of hemopoietin by mononuclear phagocytes.

Immunomodulating Properties of Humic Acids Extracted from Oligotrophic Sphagnum magellanicum Peat

Humic acids extracted with sodium pyrophosphate from Oligotrophic Sphagnum magellanicum peat reduce mitogen-stimulated production of anti-inflammatory cytokine IL-10 by mouse peritoneal macrophages and do not affect the secretion of IL-4 by lymphocytes. The studied humic acid sample stimulates the production of proinflammatory cytokines IL-12, TNFα, IL-1β, and IFNγ by immunocompetent mouse cells and human mononuclear cells. Course administration of humic acids to mice enhances the humoral immunity, increasing the number of antibody-forming cells in the spleen and the titer of antibodies in the blood serum after immunization with sheep red blood cells.

Study of Immunotropic Properties of Water-Soluble Polysaccharides Isolated from Conium maculatum Grass

Addition of water-soluble polysaccharides isolated from Conium maculatum L. to the mouse peritoneal macrophage culture induces classical activation of antigen-presenting cells due to an increase in NO synthase activity and a decrease in arginase expression.

Effects of Humic Acids, Isolated from High-Moor Pine-Peat Moss-Cotton Grass Peat on the Production of Cytokines by Mouse and Human Immunocompetent Cells and on Humoral Immune Response

A course of treatment with humic acids extracted with sodium pyrophosphate from high-moor pine-peat moss-cotton grass peat improves humoral immune response of C57BL/6 mice, stimulates the production of TNFα, IL-1β, and IL-12 by the animal peritoneal macrophages and the production of IFNγ and TNFα by donor peripheral blood mononuclears, causing no changes in the production of IL-10 in vitro.

Influence of Humic Acids Extracted from Peat by Different Methods on Functional Activity of Macrophages in Vitro

We studied activation of macrophages with humic acids extracted from peat of large deposits in the Tomsk region by two extraction methods: by hydroxide or sodium pyrophosphate. Humic acid of lowland peat types containing large amounts of aromatic carbon, phenolic and alcohol groups, carbohydrate residues and ethers, irrespectively of the extraction methods contained LPS admixture that probably determines their activating properties. Humic acid of upland peat types characterized by high content of carbonyl, carboxyl, and ester groups enhance NO production and reduce arginase expression, but these effects were minimized when sodium hydroxide was used as an extraction solvent. Pyrophosphate samples of the upland peat types were characterized by aromaticity and diversity of functional groups and have a significant advantage because of they induce specific endotoxin-independent stimulating action on antigen presenting cells.

Effects of Humic Acids Isolated from Peat of Various Origin on in Vitro Production of Nitric Oxide: a Screening Study

A screening study of biological activity of native humic acids isolated from peat was performed; several physical and chemical parameters of their structures were studied by UV- and infrared spectroscopy. Spectroscopy yielded similar shape of light absorption curves of humic acids of different origin, which can reflect similarity of general structural principles of these substances. Alkaline humic acids have more developed system of polyconjugation, while molecular structures of pyrophosphate humic acids were characterized by higher aromaticity and condensation indexes. Biological activity of the studied humic acids was assessed by NO-stimulating capacity during their culturing with murine peritoneal macrophages in a wide concentration range. It was shown that due to dose-dependent enhancement of NO production humic acids can change the functional state of macrophages towards development of pro-inflammatory properties. These changes were associated with high activity of humic acids isolated by pyrophosphate extraction, which allows considering effects of isolation method on biological activity.

Effects of Water-Soluble Polysaccharides with Different Chemical Structure, Isolated from Acorus calamus L. and Trifolium pratense L., on Nitric Oxide Production: A Screening Study

Screening study of the effects of sweet flag (Acorus calamus L.) rhizome and clover (Trifolium pratense L.) aerial part on the production of NO by mouse macrophages was carried out. The polysaccharides were separated by ion exchange chromatography into fractions differing by monomeric composition and ramification type and were used in concentrations of 20, 40, and 100 μg/ml. Four fractions of Acorus calamus L. (PSF-101, PSF-102, PSF-103, and PSF-105), used in different concentrations, moderately stimulated nitrite production by macrophages. Three of five Trifolium pratense L. polysaccharides (PS62-3, PS62-4, and PS62-5) exhibited a significant specific effect on NO production. Rhamnogalactouronans from clover PS63-3 in all concentrations and from PS62-5 in a concentration of 100 μg/ml exhibited the highest activity, comparable to the NO-stimulatory activity of the reference LPS, while polysaccharide PS62-3 in a concentration of 40 μg/ml exhibited even higher activity.

Participation of signaling cascades in the regulation of erythropoiesis under conditions of cytostatic treatment

We studied the role of signaling pathways in the regulation of erythropoiesis against the background of myelosuppression caused by administration of 5-fluorouracil. The important role of cyclic AMP in the maturation of erythroid progenitors after cytostatic treatment was demonstrated. The secretory activity of myelokaryocytes during the period of erythroid hemopoiesis recovery is mainly regulated via the p38 MAPK signaling pathway; non-erythropoietin factors are involved in the formation of erythropoietic activity of adherent cells of the microenvironment.

Involvement of cAMP- and IKK-2-dependent signal pathways in the growth capacity of mesenchymal progenitor cells under the influence of basic fibroblast growth factor

We studied the role of cAMP- and IKK-2-dependent pathways under conditions of functional stimulation of mesenchymal progenitor cells by basic fibroblast growth factor. An adenylate cyclase inhibitor 2',5'-dideoxyadenosine had no effect on functional activity of early (primitive) mesenchymal precursors. This agent produced a stimulatory effect on proliferation of stromal precursor cells. Mitotic activity of mesenchymal progenitor cells was shown to decrease after treatment with a specific blocker of the IKK-2 kinase-inhibitor complex.

Signaling events during macrophage activation with Betula pendula roth pectic polysaccharides

We studied the effect of two pectic polysaccharides PS-B1-AG and PS-B2-RG that were contained in total polysaccharides extracted from Betula pendula leaves on NO production by mouse macrophages and the contribution of signaling molecules to macrophage activation by the test substances. Unlike the total sample, pectins produced a NO-stimulating effect on macrophages. The effect of PS-B2-RG (10 μg/ml) did not differ from the effect of LPS, while PS-B1-AG produced this effect only in a concentration of 20 μg/ml, which was probably due to differences in the chemical structure of the test substances. The studied pectin polysaccharides activated transcription factor NF-κB, kinases p38 and PI3, and cAMP as a negative regulator. These results indicate that Betula pendula polysaccharides are promising substances for creation of immunomodulating drugs.

Effect of NF-κB inhibitor aurothiomalate on local inflammation in experimental Th1- and Th2-type immune response

We compared the effect of NF-κB inhibitor aurothiomalate and voltaren on local inflammation in different types of immune response. Both substances reduced edema caused by sheep erythrocytes (Th1-type immune response) and local immediate-type hypersensitivity response induced with ovalbumin (Th2-dependent response). The anti-inflammatory effects of aurothiomalate were similar to those of voltaren during Th1-type immune response.

[Effect of plant polysaccharides on TH1-dependent immune response: screening investigation]

We have studied the influence of water-soluble polysaccharides isolated from Tussilago farfara L. leaves, Betula verrucosa Ehrh. leaves, Calendula officinalis L. flowers, Acorus calamus rhizomes, Inula helenium L. rhizomes, overground part of Trifolium pretense L., and overground part ofArtemisia absinthium L., on Thl immune response induced by sheep red blood cells and on NO production by murine peritoneal macrophages in vitro. All the investigated polysaccharides have stimulated a Th1 response. Polysaccharides isolated from Betula verrucosa leaves did not influence NO synthesis, while polysaccharides of Tussilago farfara leaves and Acorus calamus rhizomes stimulated NO synthase of murine macrophages on a level comparable with that of lipopolysaccharides (LPS). Polysaccharides from Inula helenium rhizomes, Calendula officinalis flowers, and overground parts of Trifolium pretense and Artemisia absinthium also stimulated NO production, but to a lower extent in comparison to LPS.

[Prospects for pharmacological regulation of macrophage activity by modulation of intracellular signal cascade]

This article is devoted to classical and alternative macrophage activation, and intracellular transmission of external signals onto genes. It presents data on postreceptor events resulting in the formation of classical or alternative properties of macrophages. The role of some molecules of intracellular signaling pathways (STAT1, NF-kappaB, IRAK, TRAF6, Jak1, Tyk2, STAT3, c-Maf, Sp1, C/EBP, CREB, STAT6, MAP-kinase, PI3-kinase, c P) in the development of proinflammatory and anti-inflammatory activities of macrophages is discussed.

[Antiallergic effect of D-glucuronic acid]

The influence of D-glucuronic acid (course administration) on a Thl and Th2 immune response was studied. It is established that D-glucuronic acid suppressed Th2-dependent immune response as it decreased the lethality from the anaphylactic shock, abolished the local anaphylactic reaction and strongly inhibited allergen-specific IgE and IgG1 production. In addition, D-glucuronic acid stimulated Thl-dependent immune response since it enhanced the delay-type hypersensitivity reaction, increased amount of antibody-forming cells and the number of antibodies in blood. It is concluded that the mechanism of the antiallergic effect of D-glucuronic acid is related to a change in the Th1/Th2 balance in favor of Th1.

Effects of natural suppressor cells on production of Th1 and Th2 cytokines and proliferation of polarized T cells

Natural suppressor cells from the bone marrow of intact animals and mice with Th1- and Th2-dependent immune response largely suppressed the production of Th1 (IFN-gamma, IL-2) and Th2 cytokines (IL-4). Antiproliferative activity of natural suppressor cells from intact and immunized animals was mediated by NO. Proliferation of Th1 cells was suppressed greater than that of Th2 cells. This selective effect of natural suppressor cells on the proliferation of target lymphocytes was due to higher stimulatory potential of Th1 cells (in comparison with Th2) towards natural suppressor cells.

Mechanism of antitumor activity of bone marrow natural suppressor cells

Co-culturing of P-815 tumor cell strain and intact mouse bone marrow cells nonadherent to plastic resulted in the appearance of soluble mediators with antitumor activity. Bone marrow cells start releasing these antiproliferative factors only after signal exchange with the target tumor cells. The cell-cell contact is an important factor for the induction of antitumor activity. Antitumor activity of bone marrow cells (similarly as immunosuppressive activity) is realized through suppressor factors; the appearance of these factors is induced by target tumor cells.

[Ehrlich tumor cells stimulate T-cell production of interferon-gamma and are resistant to autocrine nitric oxide]

Ehrlich tumor cells released factors which activated T-cell production of interferon-gamma and triggered a mechanism of nitric oxide (NO) production instead of interferon-gamma. When cultured in vitro, they produced NO without stimulation and responded to interferon-gamma by an output rate of NO significantly greater than that in bone marrow cells. Unlike P-815 cells, those of Ehrlich tumor proved resistant to autocrine NO.

Effect of antibodies to histamine in ultralow doses on production of allergen-specific antibodies

We studied the effects of potentiated antibodies to histamine on production of IgE and IgG1 in response to 3-fold immunization of mice with ovalbumin in doses of 0.5, 10, and 100 microg. The course of treatment with antibodies to histamine suppressed production of allergen-specific IgE and IgG1 in mice 2-fold immunized with ovalbumin in doses of 100 and 0.5 microg, respectively. In mice immunized 3 times with ovalbumin in various doses the preparation suppressed production of IgE and IgG1.

Hemopoietic and lymphoid organs in AKR/JY mice with thymic lymphoma

Cytological and histological studies of the thymus, bone marrow, peripheral blood, spleen, and lymph nodes in 6-9-month-old AKR/JY mice showed that the risk of thymic lymphoma in these animals increased with age. Generalization of the tumor process was observed in mice aged over 8 months and first involved the spleen, then the lymph nodes, bone marrow, and liver. A case of primary lymphoma in the spleen was detected.