The integration of nucleotides into the growing chain of viral DNA RN A blocks viral replication and slows the spread of the disease. The virus titer was determined using the system T NP/V, where N is the amount of seeded cells, P is the share of the infected cells in the populace, V is the amount of the added supernatant containing pseudo HIV 1 particles, and T is virus Chk2 inhibitor titer. The samples with virus titer of 5 05 5 106 were utilized in this study. Analysis of the viral activity of compounds In order to assess the anti HIV 1 activity, a remedy of the analyzed materials in water or dimethylsulfoxide, was added to the cells, after 2 8 h, the cells were infected with pseudo HIV 1 particles. The general level of infection was determined by movement cytofluorimetry on an Epics 4XL Beckman Coulter instrument 48 h following infection. RESULTS AND DISCUSSION Construction of pseudo HIV 1 particles and using them to infect various eukaryotic cell lines Efficiency of transduction of target cells with pseudo HIV 1 particles, and thus the fluorescence level of the resulting transgenic cells, is the most critical parameter of a lentiviral system. This parameter Latin extispicium depends on the construction of pseudoviral particles and the particular type of infected target cells. The transplantable human lymphoblastic cells Jurkat and CE M Empire Simba, Kasumi 1, and mouse embryonic fibroblasts SC 1 were employed as target cells. Two forms of pseudo HIV 1 particles varying in coat proteins were obtained and subjected to study. Particles of the first type contain the HIV 1 coat protein gp160, particles of the next type contain the vesicular stomatitis virus G protein. The usage of particles of the first type led to a relatively low transduction performance and a weaker fluorescence signal in the infected cells. In the case of pseudo HIV 1 particles carrying the VSV G protein, the share of infected cells and the Bortezomib ic50 level of expression of the green fluorescent marker protein were considerably higher. . More over, the particles pseudo typed with the VSV G protein can be used to transfer marker genes to the cells with broad form and tissue specificity. This process enables one to perform the search for retroviruses influencing tissues besides body. Consequently, pseudo HIV 1 particles with the VSV G protein were those utilized in most studies specialized in the research of the qualities of inhibitors of HIV 1 reverse transcriptase and integrase. Nucleoside inhibitors of HIV 1 reverse transcriptase Modified nucleosides and nucleotides have found broad application in the treatment of numerous viral diseases, including the HIV 1 infection. Their mechanism of action involves transformation of those compounds, in a cell, into the corresponding nucleoside triphosphates, which behave as ending substrates for viral DNA and RN A polymerases.