Нокдаун клеточных генов FLT4, Nup98 и Nup205 как супрессор вирусной активности гриппа А/WSN/33 (H1N1) в культуре клеток А549

Objectives. To evaluate the effect of cellular genes FLT4, Nup98, and Nup205 on the reproduction of the influenza A virus in A549 human lung cancer cell line.Methods. The work was carried out using the equipment of the center for collective use of the I.I. Mechnikov Research Institute of Vaccines and Sera (Russia). The virus-containing fluid was collected within three days from the moment of transfection and infection and the intensity of viral reproduction was assessed by viral titration and hemagglutination reaction. The viral RNA concentration was determined by real-time reverse-transcription polymerase chain reaction (RT-PCR). To calculate statistically significant differences between groups, the nonparametric Mann–Whitney test was used.Results. In cells treated with small interfering RNAs (siRNAs) targeted at FLT4, Nup98, and Nup205 genes, a significant decrease in their expression and indicators of viral reproduction (virus titer, hemagglutinating activity, viral RNA concentration) was observed at a multiplicity of infection (MOI) = 0.1. Additionally, it was found that a decrease in the expression of target genes using siRNA does not lead to a significant decrease in cell survival. The viral titer in cells treated with siRNA FLT4.2, Nup98.1, and Nup205 on the first day was lower by an average of 1.0 lg, and on the second and third days, by 2.2–2.3 lg, compared to cells treated with nonspecific siRNA. During real-time RT-PCR, a significant decrease in the concentration of viral RNA was observed with siRNA Nup98.1 (up to 190 times) and Nup205 (up to 30 times) on the first day, 26 and 29 times on the second day, and 6 and 30 times on the third day, respectively. For FLT4.2 siRNA, the number of viral RNA copies decreased by 23, 18, and 16 times on the first, second, and third days. Similar results were obtained when determining the hemagglutinating activity of the virus. The hemagglutinating activity on the third day most strongly decreased in cells treated with siRNA Nup205 and FLT4.2 (16 times). In cells treated with siRNA FLT4.1, Nup98.1, and Nup98.2, hemagglutinating activity decreased by 8 times.Conclusions. In the present study, three cellular genes (FLT4, Nup98, and Nup205) were identified—the decrease in the expression of which effectively suppresses viral reproduction— and the original siRNA sequences were obtained. The results obtained are important for creating therapeutic and prophylactic medication, whose action is based on the RNA interference mechanism.Цели. Оценка влияния подавления экспрессии клеточных генов FLT4, Nup98 и Nup205 на динамику репродукции вируса гриппа А в культуре легочных клеток человека А549.Методы. Работа выполнена с использованием оборудования центра коллективного пользования Научно-исследовательского института вакцин и сывороток им И.И. Мечникова (Россия). Вируссодержащую жидкость отбирали в течение трех дней с момента трансфекции и заражения и оценивали интенсивность вирусной репродукции методами титрования по цитопатическому действию и в реакции гемагглютинации. Концентрацию вирусной РНК определяли методом полимеразной цепной реакции (ПЦР) в реальном времени с обратной транскрипцией (ОТ-ПЦР-РВ). Для вычисления статистически значимых различий между группами использовали непараметрический критерий Манна–Уитни.Результаты. В клетках, обработанных малыми интерферирующими РНК (миРНК) к генам FLT4, Nup98 и Nup205, отмечалось достоверное подавление экспрессии целевых генов и показателей вирусной репродукции (титр вируса, гемагглютинирующая активность, концентрация вирусной РНК) при коэффициенте множественности заражения, равном 0.1. Дополнительно было установлено, что подавление экспрессии целевых генов с помощью миРНК не приводит к значительному снижению выживаемости клеток. Вирусный титр в клетках, обработанных миРНК FLT4.2, Nup98.1 и Nup205, на первые сутки был меньше в среднем на 1.0 lg, а на вторые и третьи – на 2.2–2.3 lg, по сравнению с клетками, обработанными неспецифической миРНК. При проведении ОТ-ПЦР-РВ отмечено достоверное уменьшение концентрации вирусной РНК с миРНК Nup98.1 (до 190 раз) и Nup205 (до 30 раз) на первые сутки, в 26 и в 29 раз на вторые и в 6 и 30 раз на третьи сутки, соответственно. Для миРНК FLT4.2 количество копий вирусной РНК уменьшилось в 23, 18 и 16 раз на первые, вторые и третьи сутки. Схожие результаты были получены при определении гемагглютинирующей активности вируса. Наиболее сильно, в 16 раз, гемагглютинирующая активность на третьи сутки снизилась в клетках, обработанных миРНК Nup205 и FLT4.2. В клетках, обработанных миРНК FLT4.1, Nup98.1 и Nup98.2, гемагглютинирующая активность уменьшилась в 8 раз.Выводы. В ходе исследования были выявлены три клеточных гена (FLT4, Nup98 и Nup205), подавление экспрессии которых позволяет эффективно уменьшить вирусную репродукцию, а также получены оригинальные последовательности миРНК. Полученные результаты имеют важное значение для создания терапевтических и профилактических препаратов, чье действие основано на механизме РНК-интерференции

Исследование противогриппозной активности комплексов миРНК против клеточных генов FLT4, Nup98 и Nup205 на модели in vitro

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.Цели. Оценка изменения вирусной активности гриппа A/WSN/33 после комплексного нокдауна комбинаций клеточных генов FLT4, Nup98 и Nup205 в культуре легочных кле­ток человека А549.Методы. Работа выполнена с использованием оборудования центра коллективного поль­зования Научно-исследовательского института вакцин и сывороток им И.И. Мечникова (Россия). Авторами выполнялась трансфекция комбинаций комплексов миРНК, вызыва­ющих одновременное нарушение экспрессии клеточных генов FLT4, Nup98 и Nup205. В течение трех дней с момента трансфекции и заражения проводился отбор надосадоч­ной жидкости и клеточного лизата для последующего определения интенсивности ви­русной репродукции по методу титрования по цитопатическому действию. Динамику изменения концентрации вирусной рибонуклеиновой кислоты (вРНК) определяли мето­дом обратной транскрипции и полимеразной цепной реакции в режиме реального вре­мени (ОТ-ПЦР-РВ). Для вычисления статистически значимых различий между группами использовали непараметрический критерий Манна-Уитни.Результаты. При использовании всех комбинаций комплексов малых интерферирую­щих РНК (миРНК) жизнеспособность клеток не снижалась ниже порогового уровня в 70%. В клетках, обработанных комплексом FLT4.2 + Nup98.1 + Nup205 при множественности заражения (Multiplicity of infection, MOI) 0.1 достоверное снижение вирусной репродукции на 1.5 lg отмечалось на первые сутки по отношению к неспецифическому и вирусному контролям. Использование комплексов миРНК при MOI 0.01 приводило к более выражен­ному противовирусному эффекту. Вирусный титр в клетках, обработанных комплек­сами миРНК FLT4.2 + Nup98.1 и Nup98.1 + Nup205 снижался на первые сутки на 1.5 lg. В клетках, обработанных комплексами FLT4.2 + Nup205 и FLT4.2 + Nup98.1 + Nup205 снижался на 1.8 и 2 lg на первые сутки и на 1.8 и 2.5 lg на вторые сутки соответствен­но по отношению к неспецифическому и вирусному контролям. При проведении ОТ-ПЦР-РВ отмечено достоверное снижение концентрации вирусной РНК. При MOI 0.1 снижение ви­русной в 295, 55 и 63 раза отмечался при использовании комплексов миРНК FLT4.2 + Nup98.1, Nup98.1 + Nup205 и FLT4.2 + Nup98.1 + Nup205 соответственно. На вторые сутки сниже­ние вирусной РНК также отмечалось в клетках, обработанных комплексом FLT4.2 + Nup98.1. Снижение вРНК на третьи сутки в 415 раз отмечалось в клетках, обработанных ком­плексом FLT4.2 + Nup205. При MOI 0.01 концентрация вРНК снизилась в 9.5 раз при ис­пользовании комплекса Nup98.1 + Nup205 относительно неспецифического и вирусного контроля.Выводы. В ходе исследования был показан выраженный противовирусный эффект ком­бинаций миРНК при одновременном подавлении активности клеточных генов (FLT4, Nup98 и Nup205), чьи продукты экспрессии играют важное участие в процессе вирусной репродукции, а также получены оригинальные конструкции комплексов миРНК. Полу­ченные результаты имеют важное значение для создания препаратов для экстренной профилактики и терапии, чье действие основано на механизме РНК-интерференции

Роль респираторных инфекций в обострениях бронхиальной астмы

Nineteen patients aged 18–65 years with moderate and severe exacerbations of atopic asthma were examined for respiratory viruses, Mycoplasma pneumoniae, and Chlamydophila pneumoniae. Interferon system, IL-4 and γ-IFN serum levels were also investigated. Viral infections (RS-virus, adenovirus, influenza types A (H1N1, H3N2) and B viruses, parainfluenza types 1 and 3 viruses) were diagnosed serologically or using PCR with direct detection of viral nucleic acids in 73.6 % of the patients. Diagnostic level of Mycoplasma pneumoniae antigen was found in 78.9 % of the patients, anti-Chlamydophila pneumoniae antibodies were detected in 31.6 %. Leukocyte interferon-producing function was decreased in all the patients.У 19 пациентов в возрасте 18–65 лет с атопической бронхиальной астмой во время тяжелых и среднетяжелых обострений проведено обследование на наличие респираторных вирусов, Mycoplasma pneumoniae и Chlamydophila pneumoniae, оценены состояние системы интерферона, уровни IL-4 и γ-IFN в сыворотке крови. У 73,6 % пациентов серологически или путем прямого выявления вирусных нуклеиновых кислот методом ПЦР подтверждено наличие вирусной инфекции (респираторно-синцитиальный вирус — РС-вирус, аденовирус, грипп А (H1N1, H3N2) и В, парагрипп 1-го и 3-го типа). У 78,9 % пациентов в сыворотке крови обнаружен антиген Mycoplasma pneumoniae в диагностически значимом титре, у 31,6 % пациентов — антитела к Chlamydophila pneumoniae. У всех пациентов отмечено выраженное снижение интерферон-продуцирующей способности лейкоцитов

SOME FEATURES OF MANIFESTATIONS OF EPIDEMIC PROCESS DURING ACUTE INTESTINAL INFECTIONS IN MOSCOW

Aim. Study manifestations of epidemic process during acute intestinal infections to establish reasons of low effectiveness of the prophylactic measures carried out and evaluation of the role of rotavirus infection in general disease structure ofintestinal infections ofunknown etiology. Materials and methods. Data on morbidity of acute intestinal infections of population of Moscow were analyzed. Hospitalized patients with acute intestinal infections were examined using real-time PCR method test-systems of laboratory of molecular virology of Mechnikov RIVS with subsequent typing. Results. Evaluation of multi-year manifestations of epidemic process of morbidity of acute intestinal infections in Moscow has shown, that the cumulative morbidity does not have a tendency of reduction, because the proportion of infections with undeciphered etiological factors is almost 80% of the total aggregate morbidity. The proportion of rotavirus infection in total morbidity of AII of established etiology increased from 53.2 in 2004 to 82.6% in 2014. Morbidity in children with rotavirus infection is 6 times higher than morbidity in adults. Conclusion. The results obtained give evidence on the necessity of carrying out specific prophylaxis against viral intestine infection, mostly of rotavirus and norovirus infections. The highest effect should have been expected from use of a bi-vaccine, development of which seems quite an actual problem

EFFECTIVENESS OF THE LOOP-MEDIATED ISOTHERMAL AMPLIFICATION WITH FLUORESCENT DETECTION IN THE DIAGNOSIS OF PARVOVIRUS ENTERITIS IN CARNIVORES

The aim of the study was to evaluate the diagnostic value of the method of loop-mediated isothermal amplification of DNA with real-time fluorescent detection (real-time LAMP, or RT-LAMP) on the model of carnivore parvoviruses. Materials and methods. Samples of feces, blood and swabs from the rectum of different species of predatory animals with parvovirus enteritis (n = 39) and healthy animals (n = 31), as well as laboratory strains of mink enteritis virus, were analyzed by RT-LAMP using SYTO-9 and SYTO-82 dyes. Real-time PCR was used as a reference method. Results. In our study, the LAMP method with real-time fluorescence detection (RT-LAMP) in the carnivore parvovirus enteritis model provides high analytical sensitivity (1.5×103 copies of DNA/ml), diagnostic sensitivity and specificity (up to 100% under optimal conditions). Comparison of the two intercalating dyes showed that the SYTO-82 dye provides a higher signal-to-background ratio (22.6 ± 2.1) than the SYTO-9 dye (6.3 ± 1.5) (p <0.0000001 ). At the same time, SYTO-9 dye at the sensitivity limit (10 copies of DNA) provides an increase in fluorescence in the reaction mixture 13 minutes earlier than for SYTO-82 (23 and 36 minutes, respectively). Conclusion. RT-LAMP is a promising method for rapid and highly sensitive «point-of-care» diagnosis of infectious diseases, as well as in conditions of livestock farms or in field conditions

Rapid diagnostics of genital herpes by loop-mediated isothermal amplification method with fluorescent detection

Introduction. Due to the high clinical significance of herpesvirus diseases, the searching of fast and effective methods for their diagnosis remains relevant.The aim of the study was to evaluate the diagnostic efficiency of the loop-mediated isothermal amplification of DNA with real-time fluorescent detection (RT-LAMP) with SYTO-82 dye on a model of herpes simplex virus (HSV) infection.Materials and methods. A total of 44 urogenital swabs containing type 1 and type 2 HSV DNA and 43 swabs without HSV DNA, including 33 samples containing the DNA of cytomegalovirus, Epstein-Barr virus and herpesvirus type 6, were studied. For RT-LAMP, Bst 2.0 WarmStart DNA polymerase, SYTO-82 dye, LAMP primers were used.Results. The high efficiency of HSV DNA detection in the RT-LAMP reaction with SYTO-82 dye was shown. RT-LAMP in optimal conditions allowed to reduce reaction time for 2-3 times compared to real-time PCR (to 35 minutes). Analytical sensitivity of HSV type 1 and 2 detection in RT-LAMP was 103 copies of DNA/ml. The diagnostic sensitivity and specificity of the RT-LAMP diagnosis of HSV infection were 96% and 100%, respectively.Discussion. RT-LAMP method has a high sensitivity and specificity comparable to RTPCR, while the risk of false positive results obtaining is minimal.Conclusion. Thus, the reaction of RT-LAMP with SYTO-82 dye allows quickly, with high sensitivity and specificity to detect HSV DNA in clinical material and can be considered as a promising point-of-care testing method

DETECTION OF ADENOVIRUS ANTIGEN BY A SURFACE-ENHANCED RAMAN SCATTERING ENZYME-LINKED IMMUNOSORBENT ASSAY

Aim. Study of the possibility of adenovirus antigen detection by recording of surface-enhanced Raman scattering (SERS) spectra of enzyme oxidized product of 3,3',5,5'-tetramethylbenzidine. Materials and methods. Clinical fecal samples containing adenoviruses, group A rotaviruses, noroviruses and healthy children samples, as well as laboratory strains of adenoviruses with a titer of 5 — 6 lg TCD50/ml were used. Sandwich immunoassay was used, the Raman spectra were recorded by a Raman spectrometer (532 nm) after incubation with silver nanoparticles. Results. The concordance of the adenovirus detection results was obtained in comparison with the enzyme immunoassay method with colorimetric detection and PCR. Conclusion. The possibility of TMB+ using as a SERS reporter and silver nanoparticles as a SERS substrate for the detection of adenovirus antigen in complex biological samples was shown

Preventing Complications in Pregnant Women with Mild and Moderate Severity of Acute Respiratory Infections

Relevance. Pregnant women are often exposed to respiratory viruses. Occasionally, the fetus may be harmed by the virus.Goal to present materials revealing the safety and effectiveness of local interferon therapy used in the initial stage of acute respiratory infection in pregnant women from 14 weeks of gestation.Materials and methods. An in-depth analysis of the results of a study of the safety and efficacy of local interferon-therapy of respiratory infections presented in more than 60 literature sources, and own research.Results. It is shown that the inclusion of interferon-α2b (Viferon®) preparation in the complex of basic ARI therapy in pregnant women leads to a decrease in the content in the nasal washout of IL-8, the growth of T-lymphocytes and T-helpers, a more pronounced tendency to decrease natural killers; positively affects the microbiocenosis of the mucous membranes of the upper respiratory tract; leads to a reduction in symptoms of acute pharyngitis, bacterial complications from the upper respiratory tract and, as a consequence, minimizes the need for systemic antibacterial therapy.Conclusions. The conclusion is made about the expediency of including the recombinant interferon-α2b (Viferon®) preparation in intranasal gel form in the complex of basic ARI therapy in pregnant women