Effect of antiviral siRNAs on the production of cytokines in vitro

Abstract

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.