S. A. Arkhipov

Effect of Preliminary Load of Macrophages with Silicium Dioxide on Phagocytosis of BCG Strain Micobacteria by Macrophages and Antimicrobial Activity

We studied the effect of preliminary loading of peritoneal macrophages with silicium dioxide on in vitro viability, phagocytosis of BCG strain mycobacteria, and the capability to destroy the phagocytosed mycobacterium tuberculosis. It was shown that preliminary loading of macrophages with silicium dioxide did not reduce their viability and stimulated phagocytosis of BCG strain mycobacteria, but reduced their antibacterial activity.

Study of Macrophages in BCG Granulomas in Different Compartments of the Mononuclear Phagocyte System

We studied in vitro morphological and functional properties of macrophages associated with their M1 and M2 polarization in different mononuclear phagocyte compartments during BCG-induced granuloma formation, namely expression patterns of cytokines IL-1α, GM-CSF, TNF-α, and clusters of differentiation CD36 and CD16/32. We showed the mosaic pattern of macrophage polarization in BCG granulomatosis manifested by simultaneous formation of different macrophage subpopulations with М1 and М2 phenotypes in the population of mononuclear phagocytes of BCG granulomas and various compartments of the mononuclear phagocyte system. These data clarify the role of the functional polarization of macrophages in the pathogenesis of tuberculosis infection.

In Vitro Effect of Oxidized Dextrans on Peritoneal Cells

We studied the dependence of in vitro dextran biocompatibility on the method of oxidation of 35-kDa dextran. The biocompatibility of dextran oxidized with potassium permanganate was higher compared to that obtained by radiochemical oxidation. It was related to the formation of peroxide compounds during radiochemical oxidation.

Hepatocyte Apoptosis in Rats Exposed to Benzo(a)pyrene

We studied the effect of benzo(a)pyrene on activity of nuclear endonucleases and expression of molecular regulator of apoptosis Bcl-2 in liver cells in rats. Intraperitoneal injection of benzo(a)pyrene (in a total dose of 60 mg/kg body weight) reduced activity of nuclear endonucleases in the liver cells, which attests to inhibition of apoptosis by the nuclear pathway. Injection of the toxicant enhanced the expression of intracellular molecular regulator of apoptosis Bcl-2 protein in the liver cells, which attested to triggering of proapoptotic signaling in these cells and organism’s attempts to limit the development of apoptosis by the mitochondrial mechanism via activation of Bcl-2-dependent anti-apoptotic defense.

In Vitro Study of Phenotypical Characteristics of BCG Granuloma Macrophages Over the Course of Granuloma Development

Structural and immunophenotypical characteristics of macrophages, associated with their polarization in the M1 and M2 directions of differentiation and activation, were studied in different morphological types of BCG granulomas by the expression of GM-CSF, IFN-γ, and FGFb cytokines and CD36 and CD16/32 differentiation clusters. The proportion of IFN-γ and FGFb macrophage subpopulations changed over the course of granuloma formation, which led to accumulation of FGFb macrophages in the granulomas. These data indicated that the formation of macrophage granulomas and their subsequent transformation into epithelioidcell granulomas were associated with dynamic quantitative changes in the subpopulations of macrophages with the morphofunctional characteristics of M1 and M2 phenotypes, determining the antibacterial and destructive potential of granulomas. These data are useful for understanding the contribution of functional polarization of macrophages to the pathogenesis of tuberculous infection and, presumably, its complications.

In Vitro Expression of IL-1α, GM-CSF, and TNF-α by Multinucleated Macrophages from BCG-Infected Mice

Peritoneal cells from intact and BCG-infected mice were explanted in vitro. In these cultures,multinucleated macrophages in different number of nuclei were formed. The intensity of multinucleated cell formation was higher in cultures from BCG-infected mice. Increasing role of amitosis in the formation of multinucleated macrophages with relatively high number of nuclei was noted with presumable domination of cell fusion mechanism. Relatively high level of IL-1α expression was noted only in the population of binucleated macrophages of BCG-infected mice in comparison with mononuclear cells. It was found macrophages from BCG-infected mice demonstrate a kind of “lineage commitment” towards multinucleated cells, which manifested in culture in initially high and increasing (with increasing the number of nuclei in cells) expression of granulocyte-macrophage CSF and TNF-α as well as initially high amitotic activity of macrophages.

Dynamics of Structural Transformations of BCG Granulomas and Expression of TNF-α and Granulocyte-Macrophage CSF by Macrophages In Vitro

The spleens were isolated from mice at different times after BCG infection and BCG granulomas were explanted and cultured in vitro. Cell migration, chemoattractant potential, and expression of TNF-α and granulocyte-macrophage CSF (GM-CSF) by macrophages migrated from granulomas were evaluated in granulomas. The number of macrophages able to migrate; migrating out of granulomas, expressing TNF-α and GM-CSF decreased with increasing the time after infection. The number of cells in “dissociating” granulomas correlates with the number of macrophages containing live BCG mycobacteria in the cytoplasm.

In Vitro Effects of Nanosized Diamond Particles on Macrophages

The effects of synthetic diamond nanoparticles (4-6 nm) on mouse macrophage biotropism and biocompatibility and the modulation of the macrophage functions (expression of IL-1α, TNF-α, GM-CSF, bFGF, and TGF-β) by nanoparticles in different concentrations were studied in vitro during exposure of different duration. Macrophage endocytosis of nanodiamonds increased with increasing the concentration of nanoparticles in culture and incubation time. Nanodiamonds exhibited high biotropism and biocompatibility towards macrophages; in doses of 10-20 μg/ml, they induced expression of GM-CSF and TGF-β, inhibited expression of bFGF, and did not stimulate IL-1α and TNF-α. These data indicate that nanodiamond capture by macrophages in the studied experimental model led to modulation of the functional status of macrophages that determine their capacity to stimulate reparative processes without increasing proinflammatory and profibrogenic status.

Effects of molecular liposomal hybrid compositions with oxidized dextrans and isonicotinic acid hydrazide on production of granulocytic macrophage colony-stimulating factor by macrophages.

The effects of molecular liposomal hybrid compositions consisting of liposomes (200–450 nm) containing oxidized dextrans (dextranals; 35–60 kDa) conjugated with isonicotinic acid hydrazide (dextrazides), their components, and native dextrans on the production of granulocytic macrophage CSF by peritoneal macrophages were studied in vitro. Dextranals proved to be more potent inductors of granulocytic macrophage CSF than native dextrans. Conjugation of nicotinic acid hydrazide with dextranals did not modify their capacity to stimulate the production of granulocytic macrophage CSF. Liposomes in the molecular liposomal hybrid compositions did not attenuate the dextrazide capacity to stimulate the production of granulocytic macrophage CSF. Molecular liposomal compositions containing 60 kDa dextrazide exhibited the most potent stimulatory effect on macrophage production of granulocytic macrophage CSF.

Formation and Some Cytophysiological Characteristics of Polynuclear Macrophages in Primary Cultures of Peritoneal Cells

We studied the formation and cytophysiological characteristics of polynuclear macrophages in primary cultures of peritoneal cells from C57Bl/6 mice. Production of reactive oxygen species and phagocytic activity in polynuclear macrophages were higher than in mononuclear macrophages. The formation of polynuclear macrophages in cultures of peritoneal cells is realized via amitosis.