Противовирусная активность лекарственного препарата на основе РНК двуспиральной натриевой соли в отношении SARS-CoV-2 in vitro

Scientific relevance. Innate immune activation in the early phases of COVID-19 infection and subsequent interferon induction may help control viral replication and protect cells not yet infected with SARS-CoV-2. Thus, immunostimulants that induce interferon (IFN), including double-stranded RNA-based agents, are a promising means of post-exposure prophylaxis and treatment of COVID-19 at early stages.Aim. The study evaluated the in vitro antiviral activity of a double-stranded RNA sodium salt-based medicinal product against SARS-CoV-2.Materials and methods. The authors analysed the double-stranded RNA sodium salt-based medicinal product RADAMIN®VIRO using Vero cells and the Delta variant of SARS-CoV-2 (B.1.617). The virus titre was calculated as the tissue cytopathic dose that caused 50% cell death. The authors measured the content of IFN-α and IFN-γ in the culture fluid by enzyme immunoassay and assessed the viral load by real-time polymerase chain reaction (using the cycle threshold value) and by titration (using Vero cells).Results. The studied double-stranded RNA sodium salt-based medicinal product at a concentration of 250 or 500 μg/mL induced IFN-α and IFN-γ expression by Vero cells, thus increasing their resistance to SARS-CoV-2. The authors evaluated the antiviral activity of the medicinal product based on the virus titre, viral load, and cell monolayer damage. The antiviral activity became clear 24 h after treatment, which confirmed the ability of the medicinal product to inhibit the replication of the SARS-CoV-2 virus in vitro as early as the first day after infection.Conclusions. The double-stranded RNA sodium salt-based medicinal product induced IFN-α and IFN-γ synthesis in Vero cells, increasing their resistance to SARS-CoV-2 infection in vitro. These results demonstrate the immunomodulatory and antiviral potential of the medicinal product.Актуальность. Активация механизмов врожденного иммунитета на ранних фазах развития инфекции COVID-19 и, как следствие, последующая индукция продукции интерферонов может способствовать контролю репликации вируса и защите еще неинфицированных SARS-CoV-2 клеток. В связи с этим в качестве средств постконтактной профилактики и лечения COVID-19 на ранних этапах представляется перспективным применение иммуностимулирующих препаратов, вызывающих индукцию интерферонов, в том числе препаратов на основе двуспиральной РНК.Цель. Оценка противовирусной активности лекарственного препарата на основе РНК двуспиральной натриевой соли в отношении вируса SARS-CoV-2 in vitro.Материалы и методы. Препарат на основе РНК двуспиральной натриевой соли (РАДАМИН®ВИРО). Эксперименты выполняли на культуре клеток Vero. В исследовании использовали вариант дельта вируса SARS-CoV-2 (B.1.617). Проводили оценку цитопатического действия вируса. Титр вируса рассчитывали как показатель тканевой цитопатической дозы, вызывающей гибель 50% клеток. Содержание интерферонов α и γ в культуральной жидкости определяли с помощью метода иммуноферментного анализа, вирусную нагрузку – методом полимеразной цепной реакции в реальном времени (по показателю Ct) и титр вируса – титрованием на культуре клеток Vero.Результаты. Внесение препарата на основе РНК двуспиральной натриевой соли в концентрациях 250 мкг/мл и 500 мкг/мл к клеткам линии Vero приводит к индукции секреции интерферонов α и γ, что повышает резистентность клеток к заражению вирусом SARS-CoV-2. Противовирусная активность исследуемого препарата, оцениваемая по значениям показателей титра вируса, вирусной нагрузки и уровня поражения клеточного монослоя, отмечается через 24 ч после его воздействия, что показывает способность препарата задерживать размножение вируса SARS-CoV-2 in vitro уже в течение первых суток после заражения.Выводы. Препарат на основе РНК двуспиральной натриевой соли индуцирует синтез интерферонов α и γ клетками линии Vero, повышая устойчивость клеток к заражению SARS-CoV-2 in vitro, что свидетельствует о иммуномодулирующем и противовирусном потенциале исследованного препарата

Widespread Horizontal Gene Transfer from Circular Single-stranded DNA Viruses to Eukaryotic Genomes

<p>Abstract</p> <p>Background</p> <p>In addition to vertical transmission, organisms can also acquire genes from other distantly related species or from their extra-chromosomal elements (plasmids and viruses) via horizontal gene transfer (HGT). It has been suggested that phages represent substantial forces in prokaryotic evolution. In eukaryotes, retroviruses, which can integrate into host genome as an obligate step in their replication strategy, comprise approximately 8% of the human genome. Unlike retroviruses, few members of other virus families are known to transfer genes to host genomes.</p> <p>Results</p> <p>Here we performed a systematic search for sequences related to circular single-stranded DNA (ssDNA) viruses in publicly available eukaryotic genome databases followed by comprehensive phylogenetic analysis. We conclude that the replication initiation protein (Rep)-related sequences of geminiviruses, nanoviruses and circoviruses have been frequently transferred to a broad range of eukaryotic species, including plants, fungi, animals and protists. Some of the transferred viral genes were conserved and expressed, suggesting that these genes have been coopted to assume cellular functions in the host genomes. We also identified geminivirus-like and parvovirus-like transposable elements in genomes of fungi and lower animals, respectively, and thereby provide direct evidence that eukaryotic transposons could derive from ssDNA viruses.</p> <p>Conclusions</p> <p>Our discovery extends the host range of circular ssDNA viruses and sheds light on the origin and evolution of these viruses. It also suggests that ssDNA viruses act as an unforeseen source of genetic innovation in their hosts.</p

Intraocular electrochemical lysis during large choroidal melanoma endoresection

Purpose: clinical case of intraocular electrochemical lysis technique at the stage of endoresection for large choroidal melanoma.Methods: Endoresection with intraoperational intraocular electrochemical lysis (ECL) was performed in one patients (1 eyes) with large choroidal melanoma T3N0M0 (tumor thickness — 10 mm, base diameter — 13,7 x 15,4 mm, juxtapapillary localization). The original method of two platinum electrodes (extrascleral anode and intraocular cathode) combined positioning was used for ECL during endoresection. Removed material was examined morphologically.Results: The tumor was removed completely. The anatomical retinal reattachment was reached. Morphological examinations testified ECL efficacy for both tumor and tumor cells destruction. Material removed during endoresection corresponded to tumor fragments in pathomorphism. There were different necrosis extensive fields: acellular detritus with tumor parenchyma complete destruction, tumor parenchyma lixiviation; coagulation necrosis with destroyed parenchyma and compacted tumor stroma. An absence of viable tumor cells and tumor fragmentation did not allow to verify histologic tumor structure.Conclusion: New vitreoretinal technologies and new intraocular methods that destroyed tumor tissue could make the endoresection perspective and reassuring organ-safe treatment mode.</p

Intraocular electrochemical lysis during large choroidal melanoma endoresection

Purpose: clinical case of intraocular electrochemical lysis technique at the stage of endoresection for large choroidal melanoma.Methods: Endoresection with intraoperational intraocular electrochemical lysis (ECL) was performed in one patients (1 eyes) with large choroidal melanoma T3N0M0 (tumor thickness — 10 mm, base diameter — 13,7 x 15,4 mm, juxtapapillary localization). The original method of two platinum electrodes (extrascleral anode and intraocular cathode) combined positioning was used for ECL during endoresection. Removed material was examined morphologically.Results: The tumor was removed completely. The anatomical retinal reattachment was reached. Morphological examinations testified ECL efficacy for both tumor and tumor cells destruction. Material removed during endoresection corresponded to tumor fragments in pathomorphism. There were different necrosis extensive fields: acellular detritus with tumor parenchyma complete destruction, tumor parenchyma lixiviation; coagulation necrosis with destroyed parenchyma and compacted tumor stroma. An absence of viable tumor cells and tumor fragmentation did not allow to verify histologic tumor structure.Conclusion: New vitreoretinal technologies and new intraocular methods that destroyed tumor tissue could make the endoresection perspective and reassuring organ-safe treatment mode

The use of ultrasound biomicroscopy in the different stages of retinopathy of prematurity

Purpose. To study anatomical-topographical features of the anterior segment of the eye at different stages of retinopathy of prematurity (ROP) based on the ultrasound biomicroscopy, to determine criteria of disease progression and to assess the possibilities to use the obtained data for an optimization of the laser and surgical treatment.Material and methods. Ultrasound biomicroscopy (UBM) was performed in 217 eyes of 123 premature babies in the gestation terms of 26-34 weeks, of them: at the ROP stage I – 44 eyes (20%) 25 newborn children, at the stage II – 35 eyes (16%) 21 newborn babies, at the stage III – 42 eyes (19%) 24 newborns, at the stage IV – 49 eyes (22.5%) 28 newborns, at the stage V – 47 eyes (21.7%) 25 newborns. the control group consisted of 20 premature babies (40 eyes) without ROP signs and other eye diseases aged from 1 to 4 months.Results. The conducted research allowed to calculate angular and linear parameters for premature babies with no ROP signs, and also for babies of the ac tive ROP stages III, IV and V. Specificity of spatial correlations in structures of the anterior segment of the eye was defined for children with different ROP stages.Сonclusion. Specific structural violations were revealed by the UBM method in the area of the far retinal periphery, as well as in the postzonular and retrolental spaces in case of the ROP stages IV and V. The use of ultrasound biomicroscopy data in the ROP case allows to optimize the parameters of laser irradiation in the ROP stages III and II with adverse types of ROP course, to clarify the volume of surgical intervention at ROP stage IV, identify the optimum area of an operational access at ROP stage V