RNA-containing Viruses Research Articles

Эффективность препарата «Ипекон®» при инфекционном перитоните кошек, доказанная в официально зарегистрированных мультицентровых рандомизированных клинических и постклинических исследованиях

Feline infectious peritonitis is a difficult-to-treat disease caused by a highly virulent biotype of a widespread feline coronavirus. Vetstem LLC has developed a drug Ipecon® based on a low-molecular compound with a direct antiviral effect against RNA-containing viruses. Ipekon® has passed all preclinical studies. The purpose of the study: to evaluate the therapeutic efficacy of the veterinary drug Ipecon® in the treatment of feline infectious peritonitis. Materials and methods: the study included 28 cats, aged 6 months to 11 years: 18 animals with exudative and 8 with non-exudative («dry») form of IPK/FIP. The animals were divided into 3 groups, taking into account the starting single dose of the drug Ipecon®: 8 mg/kg, 10 mg/kg, 12 mg/kg. The finished solution was administered subcutaneously daily, once a day, with an interval between injections of 24 hours during the entire course of treatment. The assessment of the treatment effectiveness was comprehensive, taking into account the data of the clinical examination, the results of general clinical and biochemical blood tests, ultrasound of internal organs. Results: of the 28 animals with diagnosed IPC/FIP included in the study, 4 (14.3%) patients had a fatal outcome caused by multiple organ failure; 85.7 % of patients had the status of «clinical recovery» at the end of the course of treatment. Good tolerability of the drug Ipecon® has been established with repeated subcutaneous use. Despite the noted discomfort during administration, there were no signs of intoxication or clinically pronounced abnormalities, deterioration in the functions of organs and systems. During the use of the drug Ipecon®, only one case was noted.

Long non-coding RNAs — regulators of rubella virus infection and antiviral response

Introduction. Rubella virus is an RNA-containing virus capable of infecting human cells and causing infectious disease. Infection of pregnant women with rubella virus can lead to abortion or congenital rubella syndrome (CRS), a set of long-term birth defects including incomplete fetal organ development and mental retardation. There is no specific treatment for rubella and CRS. The regulation of antiviral immune response and viral reproduction by long non-coding RNAs is currently under active investigation. In this study, we evaluated the changes in the expression profile of long non-coding RNAs in rubella virus-infected A549 epithelial by RNA sequencing. Materials and Methods. A549 cells were infected with a wild-type variant of laboratory strain C-77 of rubella virus with a multiplicity of infection of 1.0 infectious units per cell and incubated for 72 hours. Virus titres were determined by the CCID method in the sensitive RK-13 cell culture. 48 h after infection, the cell monolayer was lysed, RNA was isolated, and libraries were prepared for sequencing. Sequencing was performed on the NextSeq500 platform (Illumina, USA) in paired-end reading mode. Validation of the obtained RNA sequencing data was performed using quantitative real-time PCR. Results. Rubella virus replication affects the production of some long non-coding RNAs by altering their expression profile. Thus, upon infection of A549 epithelial cells with rubella virus, there was a significant increase in the expression of such long non-coding RNAs as GAS5, NEAT1, LUCAT1, MIR210HG, MEG3, EPB41L4A-AS1, ZFAS1, and SNHG 1, 7, 12, 29, 32. DANCR, IGFL2-AS1, IGFL2-AS1, MIR1915HG, and SNHG14 were most significantly decreased in expression. Gene ontology (GO)-analysis revealed that long non-coding RNAs are involved at different levels in the mechanisms of immune response, in particular, RNA processing and nucleic acid metabolism; therefore, up- and down-regulation of these molecules leads to modulation of human antiviral immune response in response to rubella virus infection. Conclusion. Thus, the regulation of long non-coding RNA production by rubella virus has been shown for the first time. Differentially expressed long non-coding RNAs can be used as prognostic and diagnostic biomarkers of viral diseases.

Genome Monitoring of SARS-CoV-2 Circulating in the Kyrgyz Republic in 2020–2021

Introduction: The RNA-containing severe acute respiratory syndrome virus SARS-CoV-2 has spread rapidly around the world by adaptation to the host through genetic evolution. The emergence of variants with genetic mutations that increase contagiousness and transmission may hamper the effectiveness of disease control programs and efficacy of vaccination. Objective: To establish dominant SARS-CoV-2 variants circulating in the Kyrgyz Republic in 2020–2021. Materials and methods: Genomic monitoring was carried out based on positive results of testing nasopharyngeal swabs. SARS-CoV-2 was detected by a real-time reverse transcription –polymerase chain reaction (RT-PCR) assay using registered commercial test kits. Genetic variants (n = 15) were determined by high-throughput sequencing on a MiSeq device (Illumina, USA) using the COVID-19 ARTIC v3 protocol. Mutational variability of SARS-CoV-2 was examined using a cluster analysis of amino acid substitutions in the S protein using Ward’s method. Nucleotide sequences from Kyrgyzstan (n = 15), Russia (n = 16), India (n = 2), and China (n = 2) were aligned using MAFFT. IQ-TREE v1.6.12 was used to infer the phylogenetic tree by maximum likelihood applying Nextstrain processes. Isolates Wuhan/Hu-1/2019 and Wuhan/WH01/2019 downloaded from the GenBank® database were considered to be the root of the tree (reference). Results: Phylogenetic data analysis revealed that SARS-CoV-2 B.1.1.7 (Alpha) was the dominant VOC variant, the proportion of which was as high as 36.4 % (12/33); B.1.351 (Beta) was also found (6.1 % or 2/33). When samples were examined for amino acid substitutions in the S-protein, B.1.1.7 Alpha (British) isolates were found to cluster into two distinct branches. Conclusion: The study of the frequency and influence of mutations on pathogenetic properties of the virus, as well as the analysis of the predominant variants of the virus will allow timely measures to be taken to counteract the spread of SARS-CoV-2 in the country. In this regard, continuous genome monitoring of circulating COVID-19 variants is necessary.

Immunoliposomes As a Promising Antiviral Agent against SARS-CoV-2

According to the World Health Organization, as of January 3, 2020 to September 13, 2023, there were approximately 23 million confirmed cases of COVID-19 reported in the Russian Federation, about 400 thousand of which were fatal. Considering the high rate of mutation of the RNA-containing virus genome, which inevitably leads to the emergence of new infectious strains (Eris and Pyrola), the search for medicinal antiviral agents remains an urgent task. Moreover, taking into account the actively mutating receptor-binding domain, this task requires fundamentally new solutions. This study proposes a candidate immunoliposomal drug that targets the S protein of SARS-CoV-2 by the monoclonal neutralizing antibody P4A1 and ensures the penetration of a highly active ribonuclease into the virus-infected cell, which degrades, among cellular RNA, viral RNA too. We demonstrate a more than 40-fold increase in the neutralizing activity of the developed drug compared to the free monoclonal neutralizing antibody.

Analysis of Antibacterial and Antiviral Properties of ZnO and Cu Coatings Deposited by Magnetron Sputtering: Evaluation of Cell Viability and ROS Production

The development and testing of antimicrobial coatings continues to be a crucial approach, considering the ongoing emergence of antibiotic-resistant bacteria and the rapid transmission of highly pathogenic viruses. In this study, three types of coatings—pure metallic copper (Cu), zinc oxide (ZnO), and a three-layer zinc oxide and copper mixed coating (ZnO/Cu/ZnO)—were deposited by magnetron sputtering on polyethylene terephthalate substrates to evaluate their antimicrobial potential using various microorganisms, including viruses. Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria were used for the assessment of antibacterial properties. Antiviral testing was performed using MS2 bacteriophage and replication-deficient Semliki Forest virus, both representing single-stranded RNA-containing viruses. The samples’ ability to cause reactive oxygen species formation was measured, and the effect on bacterial metabolic activity was evaluated. Cu-coated samples showed high inhibitory activity (>95%) against E. coli and S. aureus bacteria, as well as against tested viruses (SFV and MS2). The antibacterial and antiviral properties of ZnO/Cu/ZnO and ZnO coatings were not significant. Although ZnO/Cu/ZnO and ZnO caused inhibition of the metabolic activity of the bacteria, it was insufficient for complete bacteria eradication. Furthermore, significant reactive oxygen species (ROS) production was detected only for single Cu-coated samples, correlating with the strong bacteria-killing ability. We suppose that the ZnO layer exhibited a low release of Zn ions and prevented contact of the Cu layer with bacteria and viruses in the ZnO/Cu/ZnO coating. We conclude that current ZnO and Cu-ZnO-layered coatings do not possess antibacterial and antiviral activity.

Viral Diversity in Samples of Freshwater Gastropods Benedictia baicalensis (Caenogastropoda: Benedictiidae) Revealed by Total RNA-Sequencing.

Previously, the main studies were focused on viruses that cause disease in commercial and farmed shellfish and cause damage to food enterprises (for example, Ostreavirusostreidmalaco1, Aurivirus haliotidmalaco1 and Aquabirnavirus tellinae). Advances in high-throughput sequencing technologies have extended the studies to natural populations of mollusks (and other invertebrates) as unexplored niches of viral diversity and possible sources of emerging diseases. These studies have revealed a huge diversity of mostly previously unknown viruses and filled gaps in the evolutionary history of viruses. In the present study, we estimated the viral diversity in samples of the Baikal endemic gastropod Benedictia baicalensis using metatranscriptomic analysis (total RNA-sequencing); we were able to identify a wide variety of RNA-containing viruses in four samples (pools) of mollusks collected at three stations of Lake Baikal. Most of the identified viral genomes (scaffolds) had only distant similarities to known viruses or (in most cases) to metagenome-assembled viral genomes from various natural samples (mollusks, crustaceans, insects and others) mainly from freshwater ecosystems. We were able to identify viruses similar to those previously identified in mollusks (in particular to the picornaviruses Biomphalaria virus 1 and Biomphalaria virus 3 from the freshwater gastropods); it is possible that picorna-like viruses (as well as a number of other identified viruses) are pathogenic for Baikal gastropods. Our results also suggested that Baikal mollusks, like other species, may bioaccumulate or serve as a reservoir for numerous viruses that infect a variety of organisms (including vertebrates).

A Non-Canonical Pathway Induced by Externally Applied Virus-Specific dsRNA in Potato Plants.

The external application of double-stranded RNA (dsRNA) has recently been developed as a non-transgenic approach for crop protection against pests and pathogens. This novel and emerging approach has come to prominence due to its safety and environmental benefits. It is generally assumed that the mechanism of dsRNA-mediated antivirus RNA silencing is similar to that of natural RNA interference (RNAi)-based defence against RNA-containing viruses. There is, however, no direct evidence to support this idea. Here, we provide data on the high-throughput sequencing (HTS) analysis of small non-coding RNAs (sRNA) as hallmarks of RNAi induced by infection with the RNA-containing potato virus Y (PVY) and also by exogenous application of dsRNA which corresponds to a fragment of the PVY genome. Intriguingly, in contrast to PVY-induced production of discrete 21 and 22 nt sRNA species, the externally administered PVY dsRNA fragment led to generation of a non-canonical pool of sRNAs, which were present as ladders of ~18-30 nt in length; suggestive of an unexpected sRNA biogenesis pathway. Interestingly, these non-canonical sRNAs are unable to move systemically and also do not induce transitive amplification. These findings may have significant implications for further developments in dsRNA-mediated crop protection.

The Unique Genome of the Virus and Alternative Strategies for its Realization.

Dedicated to the 130th anniversary of Dmitry Ivanovsky's discovery of the virus kingdom as a new form of biological life. The genome of some RNA-containing viruses comprises ambipolar genes that are arranged in stacks (one above the other) encoding proteins in opposite directions. Ambipolar genes provide a new approach for developing viral diversity when virions possessing an identical genome may differ in its expression scheme (strategy) and have distinct types of progeny virions varying in the genomic RNA polarity and the composition of proteins expressed by positive- or negative-sense genes, the so-called ambipolar virions. So far, this pathway of viral genome expression remains hypothetical and hidden from us, like the dark side of the Moon, and deserves a detailed study.

БИЗНЕС-ЛОГИСТИЧЕСКИЙ ПОДХОД К ИССЛЕДОВАНИЮ ФАРМАЦЕВТИЧЕСКОГО РЫНКА ПРЕПАРАТОВ ХАБАРОВСКОГО КРАЯ ДЛЯ ЛЕЧЕНИЯ ГРИППА, ОРВИ

Analyzing the infectious morbidity of the population, it should be noted that the predominant places in the general structure belong to such nosologies as influenza and SARS, which more than 35 million citizens get sick in the country every year. In this regard, the generated economic damage reaches, according to various sources, 50-100 billion rubles /year, while the total damage from the entire group of infectious diseases ranges from 80-125 billion rubles/year. Due to the fact that the peak incidence occurs in the autumn-spring period, it is at this time that the greatest demand for antiviral drugs (LP) is noted. Due to the high variability of the antigenic structure of RNA-containing viruses (more than two thousand variants of strains) and the airborne transmission pathway, which increases the distribution area, data infections are widespread among the population and are registered annually not by single outbreaks, but cause a wave of epidemics with a lethality of 250-650 thousand people/year. The greatest danger of these viruses is for people with not yet formed and (or) weakened immunity: children, pregnant women, the elderly, especially if it occurs not in mild or moderate, but in severe or toxic forms, causing a number of complications. The article presents an overview of the research of the Khabarovsk Territory pharmaceutical market of drugs for the treatment of influenza, acute respiratory viral infections for the period of 2016-2020. The aim of the research was to study the consumption range of drugs for the treatment of influenza and ARVI in the Khabarovsk Territory of the Russian Federation. Based on the data obtained, we can draw conclusions on the quality of this region’s pharmaceutical care to the population with influenza and ARVI in the period under review.

Aprotinin-Drug against Respiratory Diseases.

Aprotinin (APR) was discovered in 1930. APR is an effective pan-protease inhibitor, a typical "magic shotgun". Until 2007, APR was widely used as an antithrombotic and anti-inflammatory drug in cardiac and noncardiac surgeries for reduction of bleeding and thus limiting the need for blood transfusion. The ability of APR to inhibit proteolytic activation of some viruses leads to its use as an antiviral drug for the prevention and treatment of acute respiratory virus infections. However, due to incompetent interpretation of several clinical trials followed by incredible controversy in the literature, the usage of APR was nearly stopped for a decade worldwide. In 2015-2020, after re-analysis of these clinical trials' data the restrictions in APR usage were lifted worldwide. This review discusses antiviral mechanisms of APR action and summarizes current knowledge and prospective regarding the use of APR treatment for diseases caused by RNA-containing viruses, including influenza and SARS-CoV-2 viruses, or as a part of combination antiviral treatment.

Antiviral properties of verdazyls and leucoverdazyls and their activity against group B enteroviruses

Enteroviruses are non-enveloped viruses of Enterovirus genus, Picornaviridae family, causing a variety of human diseases: from acute respiratory and intestinal infections to more severe pathologies including poliomyelitis, encephalitis, myocarditis, pancreatitis. Currently, no approved direct-acting antiviral drugs for treatment of enterovirus infections exists, whereas vaccination is available only for prevention of poliomyelitis and enterovirus 71 infection. Therefore, it is promising to conduct a search for inhibitors of enteroviruses life cycle in drug development to treat enterovirus infections. Here, antiviral properties of stable free radicals, verdazyls, and their precursors, leucoverdazyls, were investigated. It has been shown that leucoverdazyls vs verdazyls increased the survival of permissive cell culture infected with coxsackievirus. The activity range of the lead leucoverdazyl against RNA-containing and DNA-containing human viruses (in the viral yield reduction assay) and its proposed mechanism of action (time of addition assay) was studied. The lead compound suppressed reproduction of group B enteroviruses in vitro, with modest activity against influenza A virus and no activity against herpes virus type 1 and adenovirus type 5. The maximum decrease in viral titers was observed upon its addition to infected cells during early and middle stages of the virus life cycle. Thus, we concluded that the studied compound has a pronounced inhibitory activity against group B enteroviruses not belonging to the class of capsid binder inhibitors, without virucidal properties. Previously, we described antioxidant properties of leucoverdazyls. It is known that many viral infections are accompanied by production of reactive oxygen species and oxidative stress, and some compounds with antioxidant properties exhibit antiviral potential. Targeted chemical modifications of leucoverdazyls and further studies of leucoverdazyl mechanism of action as well as in vivo animal studies are needed. However, the results obtained may be useful for future development of new antiviral drugs to treat enteroviral infections.

A Concise Review on Hepatitis C Virus Infection-Associated Type 2 Diabetes Mellitus and Its Impact on Anti-HCV Therapy

Hepatitis C virus (HCV), an RNA-containing virus, has infected more than 170 million people worldwide and is one of the leading causes of deaths in developing countries due to its propensity to progress to chronic states, followed by multiple fibrosis and scar formation (cirrhosis) and even hepatocellular carcinoma. Type 2 diabetes mellitus (T2DM), a metabolic disorder, is one of the diseases of civilization, and its prevalence has shown an increasing tendency globally. At present, more than 350 million people worldwide are suffering from T2DM. T2DM is considered the most common extrahepatic linkage of HCV infection, which is associated with prevalent morbidity and mortality patterns. Several studies have reported that HCV patients are more prone to developing T2DM as compared to healthy non-infected individuals. Extensive studies have revealed that HCV patients tend to develop insulin resistance (IR), which plays a crucial role in the development of T2DM. IR develops through several pathophysiological mechanisms, including the inhibition of insulin signaling pathway that induces central IR by HCV proteins and increased lipolysis as well as the overproduction of inflammatory cytokines, which promote peripheral IR. IR has a direct effect on the association of HCV with T2DM, and it has been found associated with impaired sustained virological response (SVR) and a higher incidence of hepatocellular carcinoma in HCV patients. Therefore, it has been suggested that chronic HCV patients must be treated with anti-HCV therapy along with antidiabetic medications to better achieve SVR. In this review, we briefly describe HCV infection, its diagnosis, global epidemiology, treatment options, and its association with DM, along with its impact on anti-HCV therapy.

How do viruses use oxidative stress?

Oxygen is a vital element for all living beings to continue their life activities and is the main component of oxidant–antioxidant metabolism, which should be in balance. The free radicals formed as a result of this metabolic process in the organism constitute a source of oxidants; external factors (radiation, exposure to sunlight, environmental pollution, cigarettes, etc.), inflammation and microbial agents also cause the formation of oxidants. Oxidative stress occurs when the balance between free radicals and antioxidants (which have an eliminating effect against them) shifts in favour of free radicals. Many studies have reported that oxidative stress may affect the virulence of pathogens during infection. Viruses use a pathological pathway that causes the production of reactive oxygen species (ROS) and the consumption of antioxidants. Thus, after viral infections, higher levels of ROS are often formed. Not only DNA-containing but also RNA-containing viruses were found to be associated with severe oxidative stress supporting DNA damage, high mutagenicity, initiation and/or progression of neoplasia. This review focuses on the relationship between oxidative stress and viruses.

NUCLEOSIDE ANALOG FAVIPIRAVIR IS A POOR INHIBITOR AGAINST THE SARS-COV-2 VIRUS IN CELL CULTURE, BUT FAVIPIRAVIR IS HIGHLY ACTIVE AGAINST VENEZUELAN EQUINE ENCEPHALITIS VIRUS

The SARS-CoV-2 pandemic has been the largest epidemiological event in the current century, however, it was not the first epidemic with a large tally in the 21st century, nor it will be the last. The majority of pathogens which have caused large epidemics in the 21st century (avian influenza, pandemic influenza, MERS, Ebola, etc.), including the SARS-CoV-2 itself, are RNA-containing viruses. The biological nature of the pathogen which will cause the future epidemic is difficult to predict, but with it highly probable will be an RNA-containing virus. To prepare for future epidemics, drug repurposing is a promising approach. The drugs repurposing against RNA viruses is facilitated by pathogens’ features such that RNA-dependent RNA polymerases have the ability to incorporate modified nucleotides into growing RNA strands; and in the majority RNA viruses, their replicases do not have the editing capacity.
 In this work, we measured the ability of two registered antiviral drugs with different mechanisms of antiviral action - Favipiravir and Cycloferon - to suppress the replication of two unrelated viruses in Vero E6 cell culture. We measured the antiviral activity against the coronavirus SARS-CoV-2 and Venezuelan equine encephalitis virus (VEEV).
 Favipiravir was not an effective inhibitor of SARS-CoV-2, because of the high half-maximal effective concentration, EC50 > 6.67 mg/ml. But Favipiravir actively suppressed the replication of the VEEV virus in the pharmacological concentration range.
 Cycloferon appeared to be a prominent inhibitor of the SARS-CoV-2 cotonavirus, demonstrating EC50 = 0.066 mg/ml. However, Cycloferon was ineffective against VEEV.
 Such differences in the activity of two drugs against two unrelated RNA-viruses are probably explained by different mechanisms of the antiviral action.

Promising opportunities to improve polio vaccines

Polioviruses belong to Enterovirus C species and cause severe lesions of the nervous system. In the post-polio eradication era, the World Health Organisation recommends inactivated polio vaccines for effective long-term protection of the population. In order to meet the needs of global health, it is planned to increase the use of traditional and optimised inactivated polio vaccines and introduce new types of vaccines that are being developed based on the current understanding of RNA-containing viruses. The aim of the study was to analyse ways of improving vaccine preparations and to review promising areas for polio immunoprophylaxis development. The authors considered innovations across all stages of the technological process, aimed at obtaining optimised vaccines, as well as vaccine delivery systems. The article presents information on new vaccine strains and cell lines for vaccine production. The authors summarised the results of clinical studies of inactivated vaccines, new vaccines based on genetically stable vaccine strains of poliovirus, and vaccines containing virus-like particles. The most likely candidates for introduction are the vaccines based on virus-like particles obtained from genetically modified strains of poliovirus. At the moment, many issues related to current trends in improving the immunoprophylaxis of poliomyelitis are debatable and need to be addressed in the near future.

PB2281: HOW TO AVOID FALSE-NEGATIVE AND FALSE-POSITIVE COVID-19 PCR TESTING

Background: Since early 2020 the most demanded molecular genetic test is real-time reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2. However, up to 40% of test results for COVID-19 in the presence of clinical manifestations of the disease might be negative. A false-negative analysis means untimely treatment of the patient and the possible spread of infection from a non-isolated person. Despite the fact that there are many highly sensitive RT-PCR test systems for COVID-19 on the market, the search for new reliable approaches to increase the robustness of testing is still relevant. Aims: To develop a PCR testing approach featured to minimize the risk of the false-negative results and to increase assay sensitivity and specificity by the use of multiple targets. Methods: A cotton swab taken from the nasopharynx was placed in an Eppendorf tube with 300 μl of phosphate-buffered saline. The resulting suspension (100 μl) was taken for RNA isolation using the Riboprep Amplisens kit (InterlabService, Russia). Primer sequences for RT-PCR are shown in Table 1. Results: The reason for a false-negative result might originate from any stage of the analysis: poor-quality or empty swab, poor RNA isolation, inactivation of reverse transcriptase or Taq polymerase in the test. To control the entire process usually control DNA or an RNA-containing virus (eg bacteriophage MS-2) is added to the sample before RNA isolation. This is sufficient to control RNA isolation, reverse transcription, and PCR amplification. However, improper swab application, handling, transporting, or even attempts to falsify the sample, cannot be excluded this way. Here we propose to include primers for the detection of human ABL1 gene RNA to control swab quality and integrity. Designed primers work with the cDNA of the ABL1 gene, not genomic DNA. Therefore achieved ABL1 gene amplification ensures that enough material containing host RNA was taken by the swab, RNA was nicely isolated, reverse transcribed, and PCR-amplified. For SARS-CoV-2 detection, we propose to use primers targeted to the conserved region of the nucleocapsid gene and the less conserved region of the spike gene (currently specific for the Omicron strain). The simultaneous appearance of three signals corresponding to the nucleocapsid, spike, and ABL1 gene indicates infection with the Omicron strain. The amplification of ABL1 gene and nucleocapsid only indicate other than Omicron infection. The appearance of ABL1 amplification only indicates a true negative result for SARS-CoV-2. All other variants are null and void. Image:Summary/Conclusion: A system has been developed for multiplex PCR diagnostics of SARS-CoV-2, which makes it possible to eliminate errors leading to false-negative and false-positive results at all stages of analysis. This is accomplished by the presence of specific primers for human RNA, controlling proper swab application, handling, and all the stages of RT-PCR. Targeting diverse regions of SARS-CoV-2 increases the reliability of the results and makes it possible to identify the virus strain.

Phase I Pharmacokinetics Study of Drug «COVID-globulin» (Specific Human Immunoglobulin Against COVID-19)

Introductio n. Coronavirus infection is an acute viral disease with a predominant lesion of the upper respiratory tract caused by an RNA-containing virus of the Coronaviridae family. However, it is known that neutralizing antibodies play an important role in antiviral therapy because they effectively inhibit the reproduction of viruses and reduce the severity of the disease. Polyclonal antibodies contained in convalescent plasma are usually used as emergency therapy for emerging infectious diseases. In this aspect, the use of a human immunoglobulin G preparation containing specific antibodies to SARS-CoV-2 ("COVID-globulin") appears to be safer and more effective. Aim. The aim is pharmacokinetics study of drug "COVID-globulin" (specific human immunoglobulin against COVID-19, solution for infusions, not less than 160 anti-COVID units/mL (ACU/mL), JSC "NPO Microgen", owner of the registration certificate of JSC "Natsibio", Russia), in addition to standard therapy for the treatment of patients with middle-grade COVID-19. Materials and methods. The clinical and analytical stages of the study of the pharmacokinetics of drug "COVID-globulin", as well as the analysis of the safety and parameters of pharmacokinetics were carried as part of a clinical study of the safety, tolerability and pharmacokinetics of the drug immunoglobulin ("COVID-globulin"), not less than 160 anti-COVID units/mL (ACU/mL), JSC "NPO Microgen", owner of the registration certificate of JSC " Natsibio", Russia. Quantitative determination of antibody concentrations against SARS-CoV-2 was carried out by enzyme-linked immunosorbent assay using spectrophotometric detection in the visible range of the spectrum on an automatic plate enzyme-linked immunosorbent assay analyzer Lazurite (Dynex Technologies Inc., USA). The calculation of pharmacokinetic parameters was carried out using the Microsoft Excel package with an extension for pharmacokinetic analysis Boomer (Department of Pharmacokinetics and Drug Metabolism, Allergan, Irvine, CA 92606, USA). Results and discussion. No serious adverse events were reported in the study, and the only adverse event that resulted in a volunteer withdrawing from the study was not related to the use of the drug. The pharmacokinetic parameters of the drug "COVID-globulin" were calculated for two batches of drugs. The pharmacokinetics of the "COVID-globulin" (the content of antibodies to SARS-CoV-2 – 330 ACU/ml) was assessed on a sample of 8 volunteers. The maximum concentration of specific IgG antibodies to the SARS-CoV-2 virus was 25.46 ± 8.71 ACU/ml (Mean ± SD, where Mean is the arithmetic mean, SD is the standard deviation). The median value of the time to maximum concentration of specific IgG antibodies to the SARS-CoV-2 virus was 0.25 hours. Specific IgG antibodies to the SARS-CoV-2 virus were eliminated from blood plasma with a half-life value 266.89 ± 59.92 hours. The pharmacokinetics of the "COVID-globulin" (the content of antibodies to SARS-CoV-2 – 250 ACU/ml) was assessed on a sample of 15 volunteers. The maximum concentration of specific IgG antibodies to the SARS-CoV-2 virus was 20.93 ± 3.82 ACU/ml. The median value of the time to maximum concentration of specific IgG antibodies to the SARS-CoV-2 virus was 0.25 hours. Specific IgG antibodies to the SARS-CoV-2 virus were eliminated from blood plasma with a half-life value 295.56 ± 50.68 hours. Conclusion. According to the results of the study, the safety profile of the drug "COVID-globulin" is assessed as favorable. Based on the concentrations of specific IgG antibodies to the SARS-CoV-2 virus obtained during the analytical stage of the study, the main pharmacokinetic parameters were calculated, and the average pharmacokinetic profiles of the test drug "COVID-globulin" were plotted after a single injection. The results obtained were the basis for the subsequent phases of clinical trials of the drug "COVID-globulin".

TREC and KREC as prognostic markers of HIV infection and COVID-19

In some infectious diseases, the number of T- and B-lymphocytes is significantly reduced which is associated with a high risk of the disease progression. The article reviews the effect of two RNA-containing viruses on the specific immune system: SARS-CoV-2 and HIV, as well as parameters of T- and B-cell neogenesis of TREC and KREC, which are markers of immunological disorders and can be used for prognosis for these infections.

The nucleotide sequence of the vp2 gene of the epizootic strain of infectious bursal disease virus and comparing it with classical and highly virulent strains

Infectious bursal disease (IBD) virus is the causative agent of a severe immunosuppressive disease in young birds. Although the disease was first discovered more than 60 years ago, it continues to pose a significant threat to the poultry industry worldwide [4]. The causative agent is RNA-containing virus, which belongs to the genus Avibirnavirus of the family Birnaviridae [17].The virion includes five viral proteins, designated VP1, VP2, VP3, VP4, and VP5 [15] with an approximate molecular weight of 97 kDa, 41 kDa, 32 kDa, 28 kDa, and 21 kDa, respectively. Additional proteins such as VPX or pVP2 are also noted [12]. The capsid protein VP2 has long been a focus of recombinant subunit vaccine development because it is responsible for eliciting a protective immune response against IBD. However, reports of many authors [2,3,6] point to the antigenic heterogeneity of IBD virus strains isolated in Russia and other countries, which is associated with the failure of existing vaccines in preventing the disease; therefore, to create and successfully use recombinant vaccines, it is necessary to study epizootic strains isolated in the Russian Federation as well.Therefore, the purpose of this work was to perform genetic analysis of the VP2 gene of the epizootic strain "Sinyavinsky" and compare it with the classical strains of IBD virus serotypes 1 and 2 isolated in Europe and highly virulent strains isolated in the Russian Federation.

Targeting of Silver Cations, Silver-Cystine Complexes, Ag Nanoclusters, and Nanoparticles towards SARS-CoV-2 RNA and Recombinant Virion Proteins.

Background: Nanosilver possesses antiviral, antibacterial, anti-inflammatory, anti-angiogenesis, antiplatelet, and anticancer properties. The development of disinfectants, inactivated vaccines, and combined etiotropic and immunomodulation therapy against respiratory viral infections, including COVID-19, remains urgent. Aim: Our goal was to determine the SARS-CoV-2 molecular targets (genomic RNA and the structural virion proteins S and N) for silver-containing nanomaterials. Methods: SARS-CoV-2 gene cloning, purification of S2 and N recombinant proteins, viral RNA isolation from patients’ blood samples, reverse transcription with quantitative real-time PCR ((RT)2-PCR), ELISA, and multiplex immunofluorescent analysis with magnetic beads (xMAP) for detection of 17 inflammation markers. Results: Fluorescent Ag nanoclusters (NCs) less than 2 nm with a few recovered silver atoms, citrate coated Ag nanoparticles (NPs) with diameters of 20–120 nm, and nanoconjugates of 50–150 nm consisting of Ag NPs with different protein envelopes were constructed from AgNO3 and analyzed by means of transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible light absorption, and fluorescent spectroscopy. SARS-CoV-2 RNA isolated from COVID-19 patients’ blood samples was completely cleaved with the artificial RNase complex compound Li+[Ag+2Cys2−(OH−)2(NH3)2] (Ag-2S), whereas other Ag-containing materials provided partial RNA degradation only. Treatment of the SARS-CoV-2 S2 and N recombinant antigens with AgNO3 and Ag NPs inhibited their binding with specific polyclonal antibodies, as shown by ELISA. Fluorescent Ag NCs with albumin or immunoglobulins, Ag-2S complex, and nanoconjugates of Ag NPs with protein shells had no effect on the interaction between coronavirus recombinant antigens and antibodies. Reduced production of a majority of the 17 inflammation biomarkers after treatment of three human cell lines with nanosilver was demonstrated by xMAP. Conclusion: The antiviral properties of the silver nanomaterials against SARS-CoV-2 coronavirus differed. The small-molecular-weight artificial RNase Ag-2S provided exhaustive RNA destruction but could not bind with the SARS-CoV-2 recombinant antigens. On the contrary, Ag+ ions and Ag NPs interacted with the SARS-CoV-2 recombinant antigens N and S but were less efficient at performing viral RNA cleavage. One should note that SARS-CoV-2 RNA was more stable than MS2 phage RNA. The isolated RNA of both the MS2 phage and SARS-CoV-2 were more degradable than the MS2 phage and coronavirus particles in patients’ blood, due to the protection with structural proteins. To reduce the risk of the virus resistance, a combined treatment with Ag-2S and Ag NPs could be used. To prevent cytokine storm during the early stages of respiratory infections with RNA-containing viruses, nanoconjugates of Ag NPs with surface proteins could be recommended.