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Ivan G. Kozlov

Publications and source records attributed to Ivan G. Kozlov.

6 recordsLinked to original sources
PubMed2001

Alpha2-Macroglobulin Modulates Interactions between Lymphocytes and Fibroblasts.

The aim of the present study was to evaluate the influence of apha2-macroglobulin (alpha(2)M) on lymphocyte adhesion to fibroblasts. Peripheral blood lymphocytes from healthy donors and two fibroblast lines (human diploid embryo fibroblasts M-19 and mouse transformed fibroblasts L929) were used in the experiments. alpha(2)M treatment of fibroblast monolayer appeared to result in the enhancement of lymphocyte adhesion to fibroblasts. The number of attached lymphocytes was increased by 2-2.5 times. It should be noted that the effect of alpha(2)M didn't depend on the conformational molecule changes, since either native or methylamine or plasmin transformed alpha(2)M approximately at the same fashion increased the lymphocyte adhesion to both allogeneic and xenogeneic fibroblasts. B lymphocytes were predominant cells that were attached to fibroblast monolayer without alpha(2)M treatment. However the percentage of adherent T lymphocytes was increased substantially after the fibroblast monolayer treatment by alpha(2)M. Subpopulation analysis has shown that fibroblast pretreatment by alpha(2)M didn't result in a selective adhesion of CD4(+) or CD8(+) T lymphocytes, but increased the adhesiveness for both T lymphocyte subpopulations. The data obtained demonstrate that besides its participation in the processes of fibroblast adhesion alpha(2)M is capable to modify the contact interaction of these cells with lymphocytes that may have an influence on the functional consequences of this process.

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PubMed2000

Adhesion of Fibroblasts to Immobilized alpha(2)-Macroglobulin.

This study examines effects of alpha(2)-macroglobulin (alpha(2)M) on adhesion of fibroblasts. Native alpha(2)M and transformed form of alpha(2)M, alpha(2)M-plasmin, were bound to plastic. Adhesion of mouse L929 and human embryo M-19 fibroblasts to immobilized alpha(2)M was estimated under various conditions by counting adherent cells using videomicroscopy and computer-assisted image analysis. alpha(2)M-plasmin, bound to plastic, induced adhesion and spreading of mouse L929 and human M-19 fibroblasts. Neither native alpha(2)M nor plasmin alone did not induce fibroblast adhesion. The adhesion to alpha(2)M-plasmin was undetectable at 4 degrees C, as well as when sodium azide was added or divalent ions were removed. These findings provide novel information on alpha(2)M functions. On the basis of these observations we hypothesized that alpha(2)M, immobilized in the extracellular matrix, can participate in the regulation of microenvironment effects on the cells, and, in particular, influence on fibroblast adhesion.

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PubMed1999

Low-Molecular Collagen Peptides Have Different Effects on Peritoneal Macrophages and Neutrophils.

Two types of phagocytes - neutrophils and macrophages, are very important participants in inflammation. However, the roles played by these cells in the regulation of an inflammation are radically different. Neutrophils initiate and ensure the alteration phase. Macrophages, to the contrary, regulate the transition of an inflammation from alternative processes to reparative. During the early stages of an inflammation, under the effect of proteases and free radicals, destruction of collagen proteins occurs and a large number of low-molecular peptides are formed, the concentration of which changes as the inflammatory reaction develops. The object of this work was to study the effect of the total fraction of low-molecular type I collagen peptides on the key functions of neutrophils and macrophages. Under the action of the wide range of concentrations of the collagen peptides (1-1000 &mgr;g/ml), activation of the neutrophil migration into the three-dimensional collagen matrix, amplification of PMA-induced production of free radicals and reduction of apoptosis of those cells were observed. The action of collagen peptides on the functions of macrophages had the opposite effect, i.e. they caused inhibition of the macrophage migration and reduction of PMA-induced production of free radicals. Furthermore, at a concentration of 100 &mgr;g/ml the collagen peptides reliably reduced the apoptosis of macrophages. Thus, collagen peptides are potent regulators of an inflammation, promoting the successive development of its phases through regulation of the functional state of phagocytes.

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PubMed1998

Low Molecular Weight Collagen Peptides Affect Migration, Proliferation and Apoptosis of Mouse Spleen Lymphocytes.

As a consequence of inflammatory tissue degradation collagen proteolysis products may be accumulated in the altered tissue. In this connection, we elaborated a hydrolysis scheme to obtain low molecular weight collagen peptides analogous to those produced in vtiro. To elucidate a possible role of collagen peptides during inflammation their action on lymphocyte migration, proliferation and apoptosis was studied at a wide range of concentrations 1-1000 &mgr;g/ml. The observed effects of peptides were different in three concentration ranges - low (1-50 &mgr;g/ml), middle (50-250 &mgr;g/ml) and high (250-1000 &mgr;g/ml). At high concentrations collagen peptides inhibited lymphocyte migration into 3D collagen matrix, and proliferation, including both spontaneous and stimulated. The middle peptide range induced lymphocyte apoptosis and modulated proliferation. Similar to middle ones, low concentration of collagen peptides modulated lymphocyte proliferation and their effect was the most pronounced. The three concentration ranges may presumably fit different stages of inflammation, since collagen degradation is associated with intensity of tissue alteration. Hence, collagen peptides may control lymphocyte functioning at different inflammation stages. Being naturally produced due to inflammatory tissue degradation, collagen peptides may be considered as complex inflammatory regulator like other traditionally discussed mediators (cytokines, chemokines, lipid mediators, etc.).

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PubMed1998

CD Antigens: Review of Data Obtained by April' 98.

CD nomenclature may be considered as chronologically set up list of elucidated molecules with each molecule number characterized by the time when it was discovered and thus by the advances in immunology. The Nomenclature Committee of World Health Organization (WHO) and International Union of Immunological Societies (IUIS) have a specialized classification department - Subcommittee on CD Nomenclature. Registration and indexing of the particular CD number to the selected clusters is carried out at International Workshops on Human Differentiation Antigens. The last 6th International Workshop was held in 1996, Kobe, Japan. In the present review we force to briefly characterize all already elucidated CD molecules that is given in a form of multicomponent table. The table partly created by us was based on the data of the last International Workshop and literature data covering the 1997-1998 period. As a commentary to the CD nomenclature table we shall try to describe structure and functions of the main families and domains, to which the majority of known CD molecules may be attributed.

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