Objectives. Evaluation of changes in the viral activity of influenza A/WSN/33 after complex knockdown of combinations of cellular genes FLT4, Nup98 and Nup205 in human lung cell culture A549. Methods. The work was carried out using the equipment of the Center for Collective Use of the I. Mechnikov Research Institute of Vaccines and Sera, Russia. The authors performed transfection of combinations of small interfering ribonucleic acid (siRNA) complexes that cause simultaneous disruption of the expression of cellular genes FLT4, Nup98, and Nup205. Within three days from the moment of transfection and infection, the supernatant fluid and cell lysate were taken for subsequent viral reproduction intensity determination using the titration method for cytopathic action. The dynamics of changes in the concentration of viral ribonucleic acid (vRNA) was determined by real-time reverse transcription polymerase chain reaction (real-time RT-PCR). The nonparametric Mann–Whitney test was used to calculate statistically significant differences between groups.Results. Using all of the combinations of siRNA complexes, cell viability did not decrease below the threshold level of 70%. In cells treated with complex FLT4.2 + Nup98.1 + Nup205 at the multiplicity of infection (MOI) equal to 0.1, a significant decrease in viral reproduction by 1.5 lg was noted on the first day in relation to nonspecific and viral controls. The use of siRNA complexes at MOI 0.01 resulted in a more pronounced antiviral effect. The viral titer in cells treated with siRNA complexes FLT4.2 + Nup98.1 and Nup98.1 + Nup205 decreased by 1.5 lg on the first day. In cells treated with complexes FLT4.2 + Nup205 and FLT4.2 + Nup98.1 + Nup205, it decreased by 1.8 and 2.0 lg on the first day and by 1.8 and 2.5 lg on the second day, respectively, in relation to nonspecific and viral controls. When conducting real-time RT-PCR, a significant decrease in the concentration of vRNA was noted. At MOI 0.1, a 295, 55, and 63-fold decrease in the viral load was observed with the use of siRNA complexes FLT4.2 + Nup98.1, Nup98.1 + Nup205, and FLT4.2 + Nup98.1 + Nup205, respectively. On the second day, a decrease in vRNA was also observed in cells treated with complex A. A 415-fold decrease in vRNA on the third day was noted in cells treated with complex FLT4.2 + Nup205. At MOI 0.01, the concentration of vRNA decreased 9.5 times when using complex B relative to nonspecific and viral control.Conclusions. The study showed a pronounced antiviral effect of siRNA combinations while simultaneously suppressing the activity of cellular genes (FLT4, Nup98, and Nup205), whose expression products are playing important role in the viral reproduction process, and obtained original designs of siRNA complexes. The results obtained are of great importance for the creation of emergence prophylactic and therapeutic drugs, whose action is based on the mechanism of RNA interference.

Influenza is one of the most urgent global health problems today. The influenza virus has immunosuppressive properties, which can lead to the development of secondary immunodeficiencies, interfering with the functioning of the interferon system activation, thus leading to impaired production of pro-inflammatory cytokines. IL-1 is the most important player in development of antiviral immunity. This cytokine plays an important role in boosting the expression of the MCP-1 and MCP-3 genes and maturation of macrophages and dendritic cells. Induction of IL-1 production occurs due to interaction of the ligand with Toll-like receptors. Currently, there is a lot of drugs aimed at the prevention and treatment of influenza infection. However, their use in some cases is difficult due to high mutational variability of the influenza virus, thus making it resistant to these drugs. Therefore, the issue of developing and creating effective methods to combat such infections is of particular importance. A promising approach to the treatment and prevention of viral respiratory infections may be connected with RNA interference. This process consists of degradation of foreign mRNA by small interfering RNA (siRNA) molecules. The aim of the present study was to evaluate expression of the IL-1 gene upon transfection of miRNA complexes directed to the cellular FLT4, Nup98, Nup205 genes. Evaluation of changed viral reproduction was carried out using titration by CPE virus-containing fluid. Expression level of the IL-1 gene was determined by means of real-time RT-PCR. Assessment of the changes in viral reproduction allowed us to reveal that the use of all the miRNA complexes directed to the cellular genes lead to a significant decrease in viral reproduction on the 1st day after infection. Usage of Nup205 + FLT4 and FLT4 + Nup205 + Nup98 complexes proved to cause a decrease in viral reproduction on the second day as well (p 0.05), as compared with nonspecific and viral controls. When analyzing expression profile of the IL-1 gene, an increase in its expression was observed on the 1st day for all miRNA complexes and on the 2nd and 3rd days for the Nup98 + FLT4 and Nup205 + Nup98 complexes. In the course of the study, it was found that suppression of the cellular genes FLT4, Nup98 and Nup205 activities, which are necessary for viral reproduction, led to a significant decrease in viral activity and an increase in IL-1 expression.

Objectives. To evaluate the dynamics of the expression level of IL-1β and IL-28β (IFN-λ3) genes as a result of complex knockdown of some cellular genes, whose expression products play an important role in the reproduction of the influenza virus.Methods. Following the collection of virus-containing liquid and cell lysate within three days from the moment of transfection and infection, the intensity of viral reproduction was assessed using the cytopathic effect titration method. The concentration of viral ribonucleic acid (vRNA) and change in the expression of IL-1β and IL-28β (IFN-λ3) were determined by real-time reverse transcription quantitative polymerase chain reaction (real-time RT-qPCR). The nonparametric Mann–Whitney test was used to statistically calculate significant differences between groups.Results. The use of each small interfering ribonucleic acid (siRNA) complex led to a decrease in viral reproduction on the first day at the multiplicity of infection (MOI) of 0.001. The use of complex A (FLT4.2 + Nup98.1) and D (FLT4.2 + Nup98.1 + Nup205) led to a decrease in viral titer by 2.8 lgTCID50/mL and by 2.1 lgTCID50/mL relative to the use of nonspecific L2 siRNA and viral control (p ≤ 0.05). Transfection of complexes B (Nup98.1 + Nup205) and C (FLT4.2 + Nup205) also reduced the viral titer by 1.5 lgTCID50/mL and 1.8 lgTCID50/mL relative to nonspecific L2 siRNA and viral control (p ≤ 0.05). When conducting real-time RT-qPCR, a significant decrease in the concentration of viral RNA was also noted. When using complexes B, C, and D, the concentration of vRNA decreased on the first day by 14.5, 4.1, and 15 times, respectively. On the second day, a decrease in vRNA was observed in cells with B and D complexes by 17.1 and 18.3 times (p ≤ 0.05). Along with a decrease in the viral titer and vRNA, an increase in the expression of the IL-1β and IL-28β genes was observed on the first day when using all siRNA complexes relative to nonspecific and viral controls (p ≤ 0.05). On the second day, an increase was also observed in cells with A and D complexes, while on the third day, there was an increase in the expression of these genes in cells with complex D (p ≤ 0.05).Conclusions. The use of siRNA complexes is shown to have a pronounced antiviral effect while simultaneously suppressing the activity of cellular genes (FLT4, Nup98 and Nup205). In parallel, the transfection of complexes that block the formation of expression products necessary for viral reproduction is demonstrated to lead to an increase in the level of expression of the IL-1β and IL-28β genes. These results indicate not only that the use of siRNA has antiviral activity, but also immunomodulatory activity, which can contribute to a more effective immune response of the body.

The human immunodeficiency virus (HIV) is currently one of the most pressing global health problems. Since its discovery in 1978, HIV has claimed the lives of more than 35 million people, and the number of people infected today reaches 37 million. In the absence of highly active antiretroviral therapy (HAART), HIV infection is characterized by a steady decrease in the number of CD4+ T-lymphocytes, but its manifestations can affect the central nervous, cardiovascular, digestive, endocrine and genitourinary systems. At the same time, complications induced by representatives of pathogenic and opportunistic microflora, which can lead to the development of bacterial, fungal and viral concomitant infections, are of particular danger. It should be borne in mind that an important problem is the emergence of viruses resistant to standard therapy, as well as the toxicity of the drugs themselves for the body. In the context of this review, of particular interest is the assessment of the prospects for the creation and clinical use of drugs based on small interfering RNAs aimed at suppressing the reproduction of HIV, taking into account the experience of similar studies conducted earlier. RNA interference is a cascade of regulatory reactions in eukaryotic cells, which results in the degradation of foreign messenger RNA. The development of drugs based on the mechanism of RNA interference will overcome the problem of viral resistance. Along with this, this technology makes it possible to quickly respond to outbreaks of new viral diseases.