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G G Karganova

Publications and source records attributed to G G Karganova.

29 records · Page 2Linked to original sources
PubMedDate not supplied

[Detection of the virus-specific proteins of the tick-borne encephalitis virus by immunosorption].

The use of immunosorption of tick-borne encephalitis (TBE) virus preparations on polyspecific antibodies covalently bound with sepharose permits good identification of virus-specific protein synthesis in cell cultures in acute and latent infection. Immune affinity separation of virus-specific proteins p93, p79, p69, p53 (V3), p24, p23, p21, p18, and p13 (NVI 1/2) attests to the high polyspecificity of the employed immune preparation, a hyperimmune anti-TBE horse serum gamma-globulin. From a virion antigen preparation, structural V3 (E) protein is isolated but not other structural proteins, V2 (C) or V1 (M). p93 protein (NV5) is one of the proteins recovered from preparations of nonvirion ("soluble") antigen (NA) alongside with heterogeneous p80 protein which may represent a product of p93 protein proteolysis or protein(s) of pig embryo kidney cells separated in immunosorption together with p93 within HA.

Animals↗
PubMedDate not supplied

[Leukocyte interferon reaction in patients with primary immunodeficiencies].

The capacity of leukocytes from children with primary immunodeficiency to produce alpha- and gamma-interferons in vitro was studied. Interferon response of leukocytes in most of the patients examined was found to be practically unchanged. The immunostimulating therapy in some cases exerted a regulating effect on leukocyte capacity for interferon production. It is assumed that the interferon-producing function of T lymphocytes may be preserved in patients suffering from primary immunodeficiency.

Adolescent↗
PubMedDate not supplied

[Changes in the host-dependent characteristics of the tick-borne encephalitis virus during its adaptation to ticks and its readaptation to white mice].

Features of multiplication in pig embryo kidney (PEK) cells of a variant of tick-borne encephalitis (TBE) virus previously selected by passages in H. plumbeum ticks and changes in the properties of the variant upon its repassages in white mouse brains were studied. The tick-adapted TBE variant differed from the original strain in the following characteristics: a lower yield of infectious virus and physical virus particles, altered time-course of infectious virus release from the cell, the lack of virions moving towards cathode in rocket immunoelectrophoresis (RIEP), reduced hemagglutinating activity of the virus, small plaque size in PEK culture, reduced level of virus replication in white mouse brain at a high cytopathic activity of the virus, and low synthesis of virus particles moving towards anode in RIEP. The acquired characteristics were stable at the level of 3 passages in white mice. In the course of further readaptation to these animals the virus recovered its capacity for synthesis of "cathode" virions in PEK cell culture, differing from the original strain by a higher level of virus reproduction in mammalian cells, altered electrophoretic mobility of the structural virion protein V1, and plaque size.

Adaptation, Physiological↗
PubMedDate not supplied

[Nonvirion (soluble) antigen of the tick-borne encephalitis virus].

Immunoelectrophoretic analysis of the cells destroyed as a result of infection with tick-borne encephalitis virus showed a considerable portion of nonvirion ("soluble") antigen to remain associated with cell membranes and to be released after treatment of the cells with detergents. After treatment with nonionic detergents, the nonvirion antigen showed electrophoretic heterogeneity in immunoelectrophoresis, and after treatment with sodium dodecyl-sulphate behaved as a homogeneous population of protein molecules. Using radioactively labeled carbohydrate precursors, lipids, and RNA, the nonvirion antigen was demonstrated to be a complex structure: a membrane-containing ribonucleoprotein. The immunoprecipitation of proteins by means of antibodies ligated to CNBr-activated sepharose confirmed that protein NV 5 (p93) of tick-borne encephalitis virus was an antigenically active component of the nonvirion antigen. This protein was found to undergo proteolytic cleavage in immunochemical reaction. The possible role of the nonvirion antigen in reproduction of flaviviruses is discussed.

Animals↗
PubMedDate not supplied

[Action of tunicamycin on the infectivity and protein synthesis of the tick-borne encephalitis virus].

Tunicamycin added in concentrations of 0.5-1 microgram/ml into the maintenance medium with tick-borne encephalitis virus (TBE) propagated in PEK cell culture inhibited incorporation of labeled carbohydrates into glycoprotein V3 as well as into virus-specific proteins NV41/2, NV3, p22, p18, p13, and p12 and to a lower degree into proteins NV5 and NV4 irrespective of the time of its addition (immediately or 17 hours after virus adsorption on the cells). In the presence of tunicamycin, incorporation of radioactive amino acids into the intracellular virus-specific proteins was inhibited, and proteins with altered electrophoretic mobility appeared. Tunicamycin in doses of 0.5-1 microgram/ml added to the infected cells immediately after virus adsorption reduced the production of extracellular virus by 2 lg PFU/ml and of intracellular virus by 1 lg PFU/ml, but exerted no inhibitory effect on virus production when added 17 hours after infection. The results indicate that protein V3 and probably all other intracellular virus-specific proteins of TBE virus exist in PEK cells in N-glycosylated form, tunicamycin selectively inhibits the stage of glycosylation of virus-specific proteins, and glycosylation of proteins affects the infectious properties and virus release from the cell.

Adsorption↗
PubMedDate not supplied

[Electron microscopic study of a tick-borne encephalitis virus-infected cell culture exposed to tunicamycin].

Ultrastructural features of tick-borne encephalitis virus-infected pig embryo cell culture treated with different concentrations of tunicamycin at various intervals after infection were studied electron microscopically. The inhibition of glycosylation did not prevent virion formation in the infected cells. At the same time, treatment with tunicamycin led to marked accumulation of virus particles in cisterns and vacuoles of the Golgi complex and to a decrease in the number of virions released into the extracellular space. It is assumed that inhibition of glycosylation leads to disorders in the regulation of the final stages of virus particles transportation and release from the infected cell. The results of the study indicate an important role of the Golgi complex in realization of the final stages of flavivirus morphogenesis.

Animals↗
PubMedDate not supplied

[Genomic changes in strains of the tick-borne encephalitis virus as a result of passages in mice].

Changes in genomes of TBE strains isolated from various sources at early stages of laboratory adaptation to white mice brain were demonstrated by molecular hybridization of nucleic acids with synthetic oligonucleotide probes, complementary RNA sites of reference TBE strains Sofyin and Neudorf. Of the 4 TBE strains passed 6 times through white mice brain in only 1 the level of RNA hybridization with 2 oligonucleotide probes was found changed, whereas in all the 3 tested strains the level of RNA hybridization with 1-2 oligonucleotide probes complementary to strain Sofyin was increased after 7-16 passages in the same system. The most noticeable changes in the genome were detected during readaptation to white mice of a TBE variant selected in passages on H. marginatum marginatum ticks.

Adaptation, Physiological↗
PubMedDate not supplied

[The electrophoretic mobility of the virus-specific proteins of tick-borne encephalitis virus strains isolated in different geographical regions of the CIS Nations].

Tick-borne encephalitis (TBE) virus strains isolated in different geographic areas were characterized by changes in electrophoretic mobility (EPM) of virus-specific proteins. Analysis of EPM of intracellular virus-specific protein E and other high molecular proteins of 42 TBE virus strains revealed similarity among the majority of them, with the exception of several strains including the Sophyin strain (Far-Eastern subtype). The most marked variability in the electrophoretic behavior of virus-specific proteins was observed with low molecular proteins prM, ns4b, ns2a.

Animals↗
PubMedDate not supplied

[Change in Na+,K+-ATPase activity during reproduction of the tick-borne encephalitis virus in SPEV cell culture].

Changes in the activity of Na(+),K(+)-ATPase during infection of SPEV cells with tick-borne encephalitis (TBE) virus were studied in preparations of cell membranes and directly in the culture and the effect of this enzyme activity on the penetration of TBE virus in the cells and production of virus-specific proteins investigated. The highest activity of the enzyme was observed directly after challenge and during the 5th and 6th hours of infection, whereas the lowest was recorded during the second and third hours and 24 h postinfection. A similar decrease in the activity of this ATPase was observed in the brain cells of infected mice. Ouabain and low (0 degree C) temperature prevented the virus penetration in the cells, which indicates that this process is energy-dependent. Inhibition of Na(+),K(+)-ATPase led to a drop in the production of virus-specific protein.

Animals↗
PubMedDate not supplied

[Adaptation of Crimean-Congo hemorrhagic fever virus to culture in Vero-E6 cells].

Adaptation of the Crimean-Congo hemorrhagic fever (CCHF) virus to continuous culturing in Vero-E6 cells was studied by coculturing of infected and intact cells. Adapted strain Hoja-A exerted a complete cytocidal effect and was characterized by a high level of virus accumulation in the early period of the infection. The resultant strain survived through more than 80 passages and retained the newly acquired properties; lyophilized, it can be stored for a long time. Availability of such a strain opens new vistas in studies of the CCHF agent.

Animals↗