The effect of Kagocel® on gene expression of Toll-like receptors of innate immunity in THP-1 human monocytes with different levels of differentiation

Abstract

Kagocel® is used in Russia for the treatment of viral infections. In terms of its chemical structure, Kagocel® active ingredient is a copolymer of gossypol polyphenol and carboxymethylcellulose. The study investigated antiviral and cytokine-inducing activity of Kagocel®, as well as its toxic effects. The aim of the study was to investigate the effect of Kagoce ® active ingredient on the induction of expression of the innate immune system receptor genes (Toll-like receptors, TLR) in the THP-1 human acute monocytic leukemia cell line with different levels of differentiation. Materials and methods: the effect of Kagocel active ingredient was investigated at the concentrations of 0.2 and 2 mg/mL in the THP-1 human acute monocytic leukemia cell line with different levels of differentiation: non-differentiated monocytes, and monocytes differentiated into macrophage-like cells. Comparative analysis of the activity of TLR 2, 3, 4, 7, 8, 9 genes was carried out by quantitative RT-PCR. The study determined standard deviations of the levels of gene expression in the experimental cells (2deltaCq ± SD) relative to the expression in the control cells. Results: Kagocel active ingredient at the concentration of 0.2 mg/mL induced activation of TLR2 expression in THP-1 monocytes by 3.5 times, TLR3 by 2 times, TLR4 by 1.6 times, and at the concentration of 2 mg/mL also induced activation of TLR7 and TLR8 by 1.4 times, and TLR9 by 2 times. The levels of TLR2, TLR3, TLR9 induction were significantly higher in THP-1 monocytes partially differentiated into macrophage-like cells, and the highest stimulation level was observed for TLR2 (8 times). Conclusions: the results obtained characterise Kagocel® as a stimulator of TLR genes in the THP-1 cell line. The number of TLR genes induced in THP-1 monocytes was shown to increase with the increase in the product concentration. THP-1 monocyte differentiation into macrophage-like cells enhances susceptibility to Kagocel®. The positive regulation of TLR genes activity may account for antiviral and interferon-inducing properties of Kagocel®, and also suggests the possibility of expanding the use of the product for various immune-associated diseases.