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Introduction: Chemotherapy of HIV infection remains the only means of treating the disease. The process of development new and improving previously developed drugs is therefore considered a priority. One of the preclinical stage of drug efficacy testing is research in the virus-cell model system in vitro ., The Aim: To evaluate the antiviral efficacy of nucleoside reverse transcriptase inhibitors (NRTIs) 6HP and 3TC during HIV-1 replication in the neoplastic MT-4 cell line., Materials and Methods: Two variants of the CD4 + T-lymphocyte MT-4 cell line (MT-4/1 and MT-4/2) transformed by Human T-lymphotropic virus type 1 (Retroviridae: Orthoretrovirinae : Deltaretrovirus : HTLV-1 ), with different levels of HIV-1 replication were used. Drugs ammonium-3'-azido-3'-deoxythymidine-5'-carbomoylphosphonat (6HP) and 2',3'-dideoxy-3'-thiacytidine (3TC) were used to suppress the virus., Results and Discussion: The replication activity of HIV-1 was observed to be higher in the MT-4/2 line than in the MT-4/1 line for different strains of the virus. The use of each of the substances separately showed a more significant inhibition of viral activity in MT-4/1 than in MT-4/2 cells. When used together, the inhibition level was almost the same in all cases and ranged from 87‒96% for the MT-4/1 line and 83‒89% for the MT-4/2 line. High efficacy was observed when using lower concentrations of drugs compared to individual use., Conclusion: The combined use of NRTIs 6НР and 3TС is promising for the treatment of HIV-infected patients at different stages of infection and with different levels of viral load.

Fractions of aqueous and water-alcohol extracts of the birch fungus Inonotus obliquus have antiviral effect against the human immunodeficiency virus type 1 (HIV-1). Antiviral properties of low toxic extracts were manifested in the concentration of 5.0 μg/ml upon simultaneous application with the virus in the lymphoblastoid cells culture MT-4. The extract of the birch fungus can be used for development of new antiviral drugs, inhibitors of HIV-replication when used both in the form of individual drugs and as a part of complex therapy.

Mutual activation of reproduction of type 1 HIV and herpes simplex types 1 and 2 viruses (HSV) was observed in simultaneous infection of continuous T-cellular lymphoblastoid lines (CEM, 119, Hut-78, MT-4, Jurkat-tat) and U-937 monocytic line. Syncytium formation and cytodestructive pattern of reproduction of viruses of both families in these cell lines necessitated the use of enzyme immunoassay (EIA) to detect the antigens of these viruses in order to assess the level of reproduction. The concentration of HIV antigens in EIA increased in mixed infection by 1.4 to 2.1 times in different cultures in comparison with the culture infected with HIV-1 alone, and concentrations of HSV-1 and HSV-2 increased by 1.3-1.8 times in mixed infection, in comparison with reproduction in lymphoblastoid cultures infected with HSV alone. EIA was alone used to examine the production of IgG and IgM antibodies to Epstein-Barr virus, another representative of Herpesviridae family, in the blood sera of patients with immunodeficiency states in whose sera antibodies to proteins produced by gag HIV gene (p15/17, p24, p55) were detected. Increased concentration of IgG antibodies were revealed in 36% of these patients, whereas in healthy donors the sera with elevated concentrations of IgG to Epstein-Barr virus were far less incident (12%). A hypothesis about mutual activation of HIV and herpes viruses is put forward.

High molecular natural (ridostin and larifan) and synthetic (camedon) interferon inducers inhibited HIV-1 replication in MT-4 and CEM cultures when administered simultaneously with the inoculum. The effect of interferon inducers was comparable with that of azidothymidine in concentrations providing cell protection. The degree of culture protection determined by the number of viable and antigen-containing cells was approximately similar for strain 899A and freshly isolated IV39. No significant difference in the efficacy of the preparations in the two different cell cultures. MT-4 and CEM, was observed. It may be assumed that the antiviral effect of the interferon inducers under study will depend little on the type of cell culture.

Trials of clinically advantageous national inducers, thymus hormones, as well as human recombinant alpha 2-interferon were carried out in cultures of continuous lymphoblastoid cells H9/IIIB infected with HIV virus. The virus-inhibiting effect for HIV was observed with interferon in doses of 10-100 IU/ml. At a concentration of interferon of 1000 IU/ml, virus replication was inhibited completely, the interferon doses used exerting no marked toxic or antiproliferative effect on the cells. Human interferon inducers, poly(G).poly(C), PXL-6, dsRNA in concentrations of 50-100 micrograms/ml inhibited virus reproduction significantly. The highest antiviral effect was achieved with yeast dsRNA. The preparations of immunomodulators, thymarin, the 5th and 7th fractions of thymosin, noticeably stimulated proliferation of infected T-lymphocytes, reducing the relative number of cells carrying the virus-specific antigen. Combined use of preparations with different mechanisms of the antiviral effect may be advantageous in prevention and treatment of AIDS.

The antiviral activity of 3'-azido-2',3'-dideoxynucleoside 5'-phosphate analogues: 5'-phosphonomethylene-3'-azido-2',3'-dideoxythymidine, 5'-methylphosphonate and 5'-phosphite of 3'-azido-2',3'-dideoxythymidine, 5'-phosphites of 3'-azido-2',3'-dideoxyadenosine and guanosine was investigated in HIV-infected cell cultures (human lymphoblastoid cells). The effectivity of inhibition of HIV-reproduction in cells by these substances was close or even higher than that for the corresponding 3'-azido-2',3'-dideoxynucleosides, whereas their toxicity was lower than that of nucleosides. These substances are supposed to be transported into the cells and to be transformed into the corresponding 5'-triphosphate analogues under the action of cell kinases. It is possible that such agents are terminator substrates of virus reverse transcriptases and thus inhibit the biosynthesis of DNA chains.

Treatment of AIDS is a complicated problem since there is a limited set of preparations tested and most of them appear to be ineffective. Their main target is HIV reverse transcriptase. The data presented show that proteolysis inhibitors are able to inhibit HIV reproduction in cell culture. The compounds used in this study, gordox and kontrikal, are officinal drugs and therefore it is worthwhile to study their effect in patients with AIDS.

Action of three nucleoside analogues with azido-group on AIDS virus (human immunodeficiency virus--HIV) reproduction was studied in two cell species. Among these compounds there were 3'-azido-3'-deoxythymidine (Az-T), 3'-azido-3'-deoxyarabinothymidine (Az-AT) and 3'-azido-2',3'-dideoxy-5-methylcytidine (Az-dCMe). All compounds prevent cells against HIV infection, but Az-T action was expressed more strongly. The reason for the lower activity of the Az-AT and Az-dCMe bases is probably stipulated by their poor conversion to the corresponding 5'-triphosphates. Az-T 5'-triphosphate blocks HIV reproduction due to the inhibition of the viral reverse transcriptase.