[INFLUENCE OF DOXORUBICIN AND ETOPOSIDE ON THE CD 95 MEDIATED APOPTOSIS IN EBV INFECTED LYMPHOMA CELLS BL-41 AND DG-75].

The aim of work was to study the effect of anticancer drugs on the process of CD 95 mediated apoptosis in BL-41 and DG-75 infected with Epstein-Barr virus. Studies of the effect of anticancer drugs "Doxorubicin" "Ebewe" and "Vepesid" (Etoposide) on the apoptosis in EBV infected cells using cytomorphological methods, spectrophotometry and PCR carried out. The influence of the tested drugs in cell culture was assessed by calculating the CC50. It was shown that it was 20 µg ml both for Etoposide and for Doxorubicin in the case of cell line DG-75. BL-41 cells were more sensitive to the tested drugs. CC50 was 5 µg/mI. PCR method showed that in the studied cell lines active accumulation of EBV DNA took place. In 24 hours after infection in the DG 75 + EBV system 20 µg/ml Doxorubicin provoked apoptosis in 89% of cells, and Etoposide-induced apoptosis was 35%. Cell culture BL-41 was equally sensitive to both drugs. At the same time, in the EBV super infected cells + Doxorubicin only 10% of apoptotic cells were detected. The obtained data prove the impact of viral infection on the sensitivity of lymphoma cells BL-41 and DG-75 to tested anticancer drugs.

Study of adenovirus reproduction in different lymphoblastoid cell lines.

The comparative characteristic of the reproduction of adenovirus serotypes 2 and 5 (HAdV-C2 and -C5) in the various lymphoblastoid cell lines were studied. Rapid formation of infectious viruses in Raji, MP-1, Namalwa, BJAB, MT4 and Jurkat cells was marked and it was found to be close to the level of viruses during reproduction in permissive Hep-2 epithelial cells. Yield of infective adenovirus was low in B95-8 cells, which were chronically infected with Epstein-Barr virus (EBV). This may indicate the interference of Ad with EBV during super-infection. The CEM cells produced chronically low amounts of human adenovirus serotype 2.

[Modelling of the adeno-herpetic infection in lymphoblastoid cell cultures].

Viral infections take the key place in medical practice. A large group of diseases are caused by adenoviral and herpes infection. As a rule, the investigations carried out in scientific laboratories are directed to the study of certain aspects of the interaction between the virus and the cell on the model of single infection. At the same time different viral infections at the level of macroorganism are constantly interacting with each other. The paper presents the studies on the selection of optimal models of lymphoblastoid cell lines for analysis of peculiarities of the mixed adeno-herpetic infection. The reproduction of human adenovirus type 5 and Epstein-Barr virus in the mono- and mixed infection in lymphoblastoid cell cultures of B-phenotype: B95-8, Raji, Namalwa have been studied. Both interfering and inhibiting action of viruses are shown. So EBV, which has a short 48-hour cycle of reproduction, inhibits the adenovirus at the given time. The obtained cell models of adeno-herpes infection will allow to study peculiarities of the antiviral action of etiotropic antiviral preparations in conditions of coinfection.

[Effect of isonicotinic acid derivates on reproduction of Epstein-Barr virus].

Current approaches to the treatment of herpes infection, particularly Epstein-Barr virus (EBV), include the use of etiotropic medicines, as well as sensitizing therapy. This virus plays an important role in the etiology of nasopharyngeal carcinoma, adenocarcinoma of the parotid glands, gastric carcinoma, Burkitt's lymphoma and lymphoproliferative syndromes [1, 2, 3]. The spectrum of drugs active against EBV remains very limited, and gancyclovir and acyclovir are used in medical practice, so the search of new compounds active against EBV remains urgent. The purpose of this work was to study antiEBV activity of isonicotinic acid derivatives in the cultures of lymphoblastoid Raji cells, B95-8, Namalwa. The indices of cytotoxicity (CC50) which amounted to 840, 1250 and 3000 microg/ml and the concentration of drugs, which inhibit the virus (IC50) reproduction is 0.1, 2.5 and 50 microg/ml, respectively, in cell cultures were identified. It was detected, the drug 4-(n-benzyl)aminocarbonyl-1-methylpyridinium iodide (PV-1) had an ability to inhibit reproduction of the Epstein-Barr virus in all studied cells cultures. The compounds PV-2 and PV-10 were less toxic in respect of the initial preparation PV-1, but their antiviral activity was manifested at 25 and 500 times higher concentrations. It, respectively, influenced the decrease of their selectivity index, which was 8400 for PV-1, 400 and 440--for PV-2 and PV-10. These studies suggest possible ways of further modification of the PV-1 molecule to create highly specific inhibitors of Epstein-Barr virus. The paper is presented in Ukrainian.

[AntiEBV activity of 6-azacytidine and its derivatives].

Epstein-Barr virus (EBV) causes several lymphoproliferative diseases, lesions of the central and peripheral nervous systems. Spectrum of etiotropic medicines against EBV is limited. The paper presents the anti-virus research of modified nucleoside with a wide spectrum of action - 6-azacytidine and its derivatives (2'-3'-seco-5-methyl-6-AC, 2',3'-dideoxy-2',3'-didehydro-6-AC and 2'-deoxy-6-AC) on the model of Epstein-Barr virus in Raji lymphoblastoid cells. Parameters of cytotoxicity (CC,) for the investigated substances were determined which amounted to 120 microg/ml, 180 microg/ml, 500 microg/ml, 330 microg/ml, and the effective concentration (ECU)--0.5 microg/ml. 1 microg/ml, 4 microg/ml, 11 microg/ml, in accordance with the sequence of preparations listed above. The results indicate a high antiEBV activity since their selectivity indexes (SI) were 240, 180, 125, 30 that is 1.3-10 times higher than the reference substance acycloguanosine. Apoptosis-stimulating action of 6-azacytidine and its derivatives was revealed. An increase of percentage of apoptotic cells in EBV-infected Raji cells and those treated with investigated substances as compared to uninfected ones was observed after 24 hours. Thus, our results provide new biological properties of the azacytidine substances.

Inhibitors of Epstein-Barr virus reproduction--ribonucleosides of 3-substituted 1,2,4-triazino[5,6-b] [1,4] benzothiasines.

Studying of antiviral effect of condensed triazine derivatives--3-oxo- triazinobenzothiazine (the preparation No 1), its ribonucleoside (the preparation No 3) and ribonucleoside of its 3-thio-analogue (the preparation No 2) on reproduction of Epstein-Barr virus (EBV) in lymphoblastoid Raji cells is reported in present work. The cytotoxic action of these preparations on test cells was determined and CC50 index was 125 microg/ml for the preparation No 1, for preparation No 2 - 625 microg/ml, and for preparation No 3 - 750 microg/ml. Antiviral activity of the preparations was tested by inhibition level of accumulation of viral DNA in the cell culture, and effective concentration (EC50 index) was determined for each preparation. EC50 constituted 1 microg/ml for each triazinobenzothiazines. Selectivity index (SI) was 125 for preparation No 1, for preparation No 2 - 625, and for preparation No 3 - 750. The obtained results of studying of triazinobenzothiazines as inhibitors of EBV-infection support their high antiEBV activity and can be interesting for further investigations.

[Effect of proteflazid on the Epschtein-Barr virus].

Cytotoxicity and anti-EBV activity ofProteflasid (SPC Ekopharm, Kyiv) in two solvents: propylene glycol (PG) and syrup--in the culture of lymphoblastoid Raji cells were studied. It was determined that cytotoxic concentration (CC50) of Proteflasid in propylene glycol was 40 microg/ml, and in syrup--150 microg/ ml; effective concentration (EC50) of Proteflasid was equal for both solvents and was 0.1 microg/ml (under therapeutic action of Proteflasid) and 0.5 microg/ml (under prophylactic action of Proteflasid). Selectivity index (SI) ofProteflasid in PG was 400 and 80 (for therapeutic and prophylactic scheme, accordingly), 1500 and 300 (for therapeutic and prophylactic scheme, accordingly) in syrup.

[Modern tendencies in the study of human viruses].

The results of fundamental and applied researches of the Department of Molecular Biology of Viruses and Virus Reproduction Laboratory created on its basis, for the recent five years are generalized in this paper. The basic trends of research of fundamental regularities of virus-cell interaction, search of the anti-virus substances, new approaches to diagnosis of human viruses were analyzed. The spectrum of practical development of the Laboratory, which includes preparations for diagnostics and treatment of human diseases, is presented.

Elaboration of optical immunosensors based on the surface plasmon resonance for detecting specific antibodies and antigens of Epstein-Barr virus and human adenovirus.

The study of antigen-antibody interaction on the model of Epstein-Barr virus (EBV) and second type adenovirus (Ad2) based on the surface plasmon resonance (SPR) was carried out. Kinetic and concentration dependences between virus antigens and specific antisera to them at different pH were determined. Experimental samples of biosensors for the detection by SPR method of virus (EBV and Ad2) antigens using monospecific antibodies, immobilized on the surface of gold, and also for detection of specific antibodies in the blood sera of patients with EBV or adenovirus infection were elaborated

[Research of modulation of CD95-mediated apoptosis in lymphoblastic MP-1 and BJAB cells infected by adenovirus and Epstein-Barr virus].

Model systems of infecting limphoblastic MP-1 and BJAB cells by Epstein-Barr virus, 5 serotype adenovirus and double infection are developed. A rather high level of accumulation of DNA of these viruses in the cells in dynamics at monoinfection and inhibition interference at multi-infection was shown by PCR method. The influence of virus infection on proliferative activity was studied. The stimulation of cells growth in the system BJAB + EBV was detected, and double infecting inhibited the process by 50%. The 25% difference in development of apoptosis process between cells infected by adenovirus and EBV was established when defining CD95-mediated apoptosis in infected MP-1 cells. The infecting of BJAB cells by viruses had a scarce effect on the processes of spontaneous apoptosis, but the data on CD95-mediated apoptosis at EBV infection testify to inhibition of this process both at a monoinfection, and at a double infection. The work was performed in the framework of the fundamental agreement of Ministry of Education and Science of Ukraine F7/366-2001, and grant INTAS N011-2382.

[Construction of the immunoenzyme test system "IFA-AtEBV-Strip" for detecting antibodies of the Epstein-Barr virus]. / Konstruiuvannia imunofermentnoï test-systemy "IFA-AtVEB-Strip" dlia vyiavlennia antytil proty virusu Epshteina-Barr.

The first home immunoenzyme test-system for finding antibodies to the Epstein-Barr virus (EBV) has been created. The test-system laboratory prototype was called "IFA-AtEBV-strip". Production technology has been developed for specific components of immunoenzyme test system and all the analysis stage conditions have been optimized: the antigen sorption on plates, its interaction with the studied serum, finding out of the formed immune complex. The test system "IFA-AtEBV-strip" sensitivity made up 96%, specificity--100%.

[Physicochemical characteristics of cyanophages and their components]. / Fiziko-khimicheskie kharakteristiki tsianofagov i ikh komponentov.

The paper presents the results of the study on the physicochemical properties of DNA, polypeptide composition of proteins, as well as features of quaternary structure of virions of cyanophages LPP-IA, LPP-3, LPP-3A, A-1, A-2, and N-2 lysing filamentous and heterocyst cyanobacteria. Such characteristics may be used as hierarchially important signs in compiling the classificational scheme of cyanophages.