[Influence of siRNA complexes on the reproduction of influenza A virus (Orthomyxoviridae: Alphainfluenzavirus) in vivo]

INTRODUCTION

Influenza is one of the most pressing global health problems. Despite the wide range of available anti-influenza drugs, the viral drug resistance is an increasing concern and requires the search for new approaches to overcome it. A promising solution is the development of drugs with action that is based on the inhibition of the activity of cellular genes through RNA interference.

AIM

Evaluation in vivo of the preventive potential of miRNAs directed to the cellular genes FLT4, Nup98 and Nup205 against influenza infection.

MATERIALS AND METHODS

The A/California/7/09 strain of influenza virus (H1N1) and BALB/c mice were used in the study. The administration of siRNA and experimental infection of animals were performed intranasally. The results of the experiment were analyzed using molecular genetic and virological methods.

RESULTS

The use of siRNA complexes Nup98.1 and Nup205.1 led to a significant decrease in viral reproduction and concentration of viral RNA on the 3rd day after infection. When two siRNA complexes (Nup98.1 and Nup205.1) were administered simultaneously, a significant decrease in viral titer and concentration of viral RNA was also noted compared with the control groups.

CONCLUSIONS

The use of siRNAs in vivo can lead to an antiviral effect when the activity of single or several cellular genes is suppressed. The results indicate that the use of siRNAs targeting the cellular genes whose expression products are involved in viral reproduction is one of the promising methods for the prevention and treatment of not only influenza, but also other respiratory infections.

[Comparative study of Wuhan-like and omicron-like variants of SARS-CoV-2 in experimental animal models]

INTRODUCTION

The variability of SARS-CoV-2 appeared to be higher than expected, the emergence of new variants raises concerns. The aim of the work was to compare the pathogenicity of the Wuhan and BA.1.1/Omicron variants in BALB/c mice and Syrian hamsters.

MATERIALS AND METHODS

The study used strains of SARS-CoV-2: Dubrovka phylogenetically close to Wuhan-Hu-1, and LIA phylogenetically close to Omicron, BALB/c mice, transgenic mice B6.Cg-Tg(K18-ACE2)2Prlmn/HEMI Hemizygous for Tg(K18-ACE2)2Prlmn, Syrian golden hamsters. Animals were infected intranasally, pathogenicity was estimated by a complex of clinical, pathomorphological and virological methods.

RESULTS

Comparative studies of SARS-CoV-2 Dubrovka and LIA strains on animal models demonstrated their heterogeneous pathogenicity. In parallel infection of BALB/c mice with Dubrovka and LIA variants, the infection proceeded without serious clinical signs and lung damage. Infection with the LIA strain resulted to a systemic disease with a high concentration of viral RNA in the lungs and brain tissues of animals. The presence of viral RNA in mice infected with the Dubrovka strain was transient and undetectable in the lungs by day 7 post-infection. Unlike the mouse model, in hamsters, the Dubrovka strain had a greater pathogenicity than the LIA strain. In hamsters infected with the Dubrovka strain lung lesions were more significant, and the virus spread through organs, in particular in brain tissue, was observed. In hamsters infected with the LIA strain virus was not detected in brain tissue.

CONCLUSION

The study of various variants of SARS-CoV-2 in species initially unsusceptible to SARS-CoV-2 infection is important for monitoring zoonotic reservoirs that increase the risk of spread of new variants in humans.

<i>CDR1, CDR2, MDR1</i> and <i>ERG11</i> expression in azole resistant <i>Сandida albicans</i> isolated from HIV-infected patients in city of Moscow

Candida fungi are common opportunistic microorganisms capable of causing infections of various localization, as well as life-threatening conditions in immunocompromised patients, such as HIV-infected individuals, oncology patients, subjects undergoing HSCT, which number has been steadily increasing in recent years. In addition, resistance to anti-fungal drugs has been spreading as well. Naturally sensitive to azoles, C. albicans possess a variety of mechanisms of acquired resistance, including efflux transporters and target protein-encoding gene amplification. This study was conducted to assess a prevalence of such mechanisms in the isolates sample obtained from HIV-infected patients in the Moscow region of the Russian Federation, characterize a relationship between these mechanisms and patterns of developing drug resistance. 18 strains of C. albicans resistant to fluconazole and voriconazole were isolated from HIV-infected patients with recurrent oropharyngeal candidiasis in the Moscow region. The expression levels of the ERG11, MDR1, CDR1, CDR2 genes involved in the formation of acquired azole resistance were measured using quantitative PCR, the 2CT method with ACT and PMA genes as control genes and reference values of sensitive isolates. Expression levels exceeding the average values of sensitive isolates by more than 3 standard deviations were considered significantly elevated. In most of the isolates, elevated levels of CDR1 and CDR2 gene expression were found: 89% and 78%, respectively. The expression level of the MDR1 gene was increased only in 28% of cases. ERG11 expression levels were significantly elevated in 78% of the isolates. Expression levels of all resistance genes studied were significantly increased in 4 strains. In this sample of C. albicans isolates, acquired resistance is mainly associated with efflux vectors encoded by the CDR1 and CDR2 genes. Also, in most isolates, an increased expression level for the azole target protein gene ERG11 was detected. The expression level of the efflux transporter gene MDR1 was increased in the smallest number of samples. It is also impossible to exclude a potential role of other mechanisms in developing acquired resistance, such as mutations in the ERG11 gene. It can be assumed that the identified mechanisms of resistance result from long-term, widespread, and sometimes uncontrolled use of azoles, including those in treatment and prevention of candidiasis in HIV-infected patients.

[The prospects for the use of drugs based on the phenomenon of RNA interference against HIV infection]

The human immunodeficiency virus (HIV) is currently one of the most pressing global health problems. Since its discovery in 1978, HIV has claimed the lives of more than 35 million people, and the number of people infected today reaches 37 million. In the absence of highly active antiretroviral therapy (HAART), HIV infection is characterized by a steady decrease in the number of CD4+ T-lymphocytes, but its manifestations can affect the central nervous, cardiovascular, digestive, endocrine and genitourinary systems. At the same time, complications induced by representatives of pathogenic and opportunistic microflora, which can lead to the development of bacterial, fungal and viral concomitant infections, are of particular danger. It should be borne in mind that an important problem is the emergence of viruses resistant to standard therapy, as well as the toxicity of the drugs themselves for the body. In the context of this review, of particular interest is the assessment of the prospects for the creation and clinical use of drugs based on small interfering RNAs aimed at suppressing the reproduction of HIV, taking into account the experience of similar studies conducted earlier. RNA interference is a cascade of regulatory reactions in eukaryotic cells, which results in the degradation of foreign messenger RNA. The development of drugs based on the mechanism of RNA interference will overcome the problem of viral resistance. Along with this, this technology makes it possible to quickly respond to outbreaks of new viral diseases.

Immunogenic properties of SARS-CoV-2 inactivated by ultraviolet light

Vaccination against COVID-19 is the most effective method of controlling the spread of SARS-CoV-2 and reducing mortality from this disease. The development of vaccines with high protective activity against a wide range of SARS-CoV-2 antigenic variants remains relevant. In this regard, evaluation of the effectiveness of physical methods of virus inactivation, such as ultraviolet irradiation (UV) of the virus stock, remains relevant. This study demonstrates that the UV treatment of SARS-CoV-2 completely inactivates its infectivity while preserving its morphology, antigenic properties, and ability to induce the production of virus-neutralizing antibodies in mice through immunization. Thus, the UV inactivation of SARS-CoV-2 makes it possible to obtain viral material similar in its antigenic and immunogenic properties to the native antigen, which can be used both for the development of diagnostic test systems and for the development of an inactivated vaccine against COVID-19.

Potential of application of the RNA interference phenomenon in the treatment of new coronavirus infection COVID-19

COVID-19 has killed more than 4 million people to date and is the most significant global health problem. The first recorded case of COVID-19 had been noted in Wuhan, China in December 2019, and already on March 11, 2020, World Health Organization declared a pandemic due to the rapid spread of this infection. In addition to the damage to the respiratory system, SARS-CoV-2 is capable of causing severe complications that can affect almost all organ systems. Due to the insufficient effectiveness of the COVID-19 therapy, there is an urgent need to develop effective specific medicines. Among the known approaches to the creation of antiviral drugs, a very promising direction is the development of drugs whose action is mediated by the mechanism of RNA interference (RNAi). A small interfering RNA (siRNA) molecule suppresses the expression of a target gene in this regulatory pathway. The phenomenon of RNAi makes it possible to quickly create a whole series of highly effective antiviral drugs, if the matrix RNA (mRNA) sequence of the target viral protein is known. This review examines the possibility of clinical application of siRNAs aimed at suppressing reproduction of the SARS-CoV-2, taking into account the experience of similar studies using SARS-CoV and MERS-CoV infection models. It is important to remember that the effectiveness of siRNA molecules targeting viral genes may decrease due to the formation of viral resistance. In this regard, the design of siRNAs targeting the cellular factors necessary for the reproduction of SARS-CoV-2 deserves special attention.

Genetic Diversity and Evolution of the Biological Features of the Pandemic SARS-CoV-2

The new coronavirus infection (COVID-19) represents a challenge for global health. Since the outbreak began, the number of confirmed cases has exceeded 117 million, with more than 2.6 million deaths worldwide. With public health measures aimed at containing the spread of the disease, several countries have faced a crisis in the availability of intensive care units. Currently, a large-scale effort is underway to identify the nucleotide sequences of the SARS-CoV-2 coronavirus that is an etiological agent of COVID-19. Global sequencing of thousands of viral genomes has revealed many common genetic variants, which enables the monitoring of the evolution of SARS-CoV-2 and the tracking of its spread over time. Understanding the current evolution of SARS-CoV-2 is necessary not only for a retrospective analysis of the new coronavirus infection spread, but also for the development of approaches to the therapy and prophylaxis of COVID-19. In this review, we have focused on the general characteristics of SARS-CoV-2 and COVID-19. Also, we have analyzed available publications on the genetic diversity of the virus and the relationship between the diversity and the biological properties of SARS-CoV-2, such as virulence and contagiousness.

Association of the NOS3 Gene Polymorphisms with the Risk of Atopic Dermatitis in Children

We studied association of polymorphic markers Glu298Asp (rs1799983), C774T (rs1549758), and T786C (rs2070744) of the NOS3 gene with the risk of atopic dermatitis. It was found that T786C polymorphic marker of the NOS3 gene is associated with lower risk of erythematosquamous lichenoid atopic dermatitis. A significant association between the homozygous CC genotype in locus 786 of the NOS3 gene and the development of erythematosquamous atopic dermatitis with lichenification was revealed. The homozygous CC genotype can be considered as a risk factor of erythematosquamous atopic dermatitis with lichenification.

[Seroprevalence of hepatitis E virus (Hepeviridae: Orthohepevirus: Orthohepevirus A) among pregnant women in the highly endemic region of Kyrgyzstan]

INTRODUCTION

Hepatitis E (HE) is an important public health problem worldwide and is especially significant for pregnant women, among whom the associated mortality rate reaches 25%. The distribution of HE serological markers in this cohort in the endemic regions of Central Asia is poorly understood. The aim of the study was to assess the seroprevalence of HEV among pregnant women in the region of Kyrgyzstan where an increased incidence of HE is reported.

MATERIAL AND METHODS

Blood serum of pregnant women, obtained from medical institutions in Bishkek, city of Osh and Osh region in the period from September 2016 to October 2019, and the control group of clinically healthy women were tested using the test systems "DS-IFA-ANTI-HEV-G" and "DS-IFA-ANTI-HEV-M" (NPO "Diagnostic Systems", Russia).

RESULTS

IgG antibodies to HEV were detected in 87 (5.9%) of 1472 examined pregnant women, IgM antibodies -in 64 (4.8%) of 1378, while 5 (0.34%) samples were simultaneously positive for IgG and IgM antibodies. The rates of detection of antibodies to HEV in women of three age categories from 17 to 36 years old in the studied and control groups were similar. The analysis of the seasonal dynamics of HEV seroprevalence in pregnant women in the period from February to September 2019 showed a tendency towards an increase in the values of the positivity coefficient of specific IgM antibodies by the beginning of the autumn. Antibodies to HEV were detected with highest frequency in women from Osh region.

CONCLUSIONS

A high risk of HEV infection for pregnant women in the surveyed region had been shown.

[The potential of synthetic small interfering RNA-based antiviral drugs for influenza treatment]

Influenza is a worldwide public health problem. Annually, this infection affects up to 15% of the world population; and about half a million people die from this disease every year. Moreover, influenza A and B viruses tend to garner most of the attention, as these types are a major cause of the epidemics and pandemics. Although the influenza virus primarily affects the respiratory tract, it may also affect the cardiovascular and central nervous systems. Several antiviral drugs, that target various stages of viral reproduction, have been considered effective for the treatment and prevention of influenza, but some virus strains become resistant to these medications. Thus, new strategies and techniques should be developed to overcome the antiviral drug resistance. Recent studies suggest that new drugs based on RNA interference (RNAi) appear to be a promising therapeutic approach that regulates the activity of viral or cellular genes. As it is known, the RNAi is a eukaryotic gene regulatory mechanism that can be triggered by a foreign double-stranded RNA (dsRNA) and results in the cleavage of the target messenger RNA (mRNA). This review discusses the prospects, advantages, and disadvantages of using RNAi in carrying out a specific treatment for influenza infection. However, some viruses confer resistance to small interfering RNAs (siRNA) targeting viral genes. This problem can significantly reduce the effectiveness of RNAi. Therefore, applying siRNAs targeting host cell factors required for influenza virus reproduction can be a way to overcome the antiviral drug resistance.

[Development and properties of neutralizing monoclonal antibodies for fusion protein of respiratory syncytial virus.]

INTRODUCTION

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections in infants and the elderly. The absence of a wide range of therapeutic drugs and vaccines indicates to the high relevance of the development of new effective drugs for the prevention and treatment of RSV infections.

PURPOSE

to obtain highly active and specific monoclonal antibodies (MAbs) capable of detecting RSV in infected cells and neutralizing the infectious activity of the virus in vitro.

MATERIAL AND METHODS

RSV reference strains of group A 2 subgroups (A2 and Long) were propagated in HEp-2 and MA-104 cell lines, respectively. Mice were immunized with purified RSV A2 virus. MAbs were obtained using hybridoma technology.

RESULTS

A panel of 6 MAbs reacting with RSV strains А2 and Long has been obtained. Four MAbs were IgG (IgG2a or IgG2b subtype), two MAbs were IgM. All MAbs reacted with RSV F-protein in immunochemical tests. The MAbs actively reacted with RSV in ELISA, in immufluorescence and peroxidase staining of infected cells, and in immunodot test. Five out of 6 MAbs neutralized of RSV in cell culture. Different properties of MAbs suggest that they target different antigenic sites of F-protein.

DISCUSSION

Comparative analysis suggests that the obtained MAbs can be used for the development of diagnostic preparations, for RSV detection in clinical materials and confirmation of infection etiology by rapid culture method.

CONCLUSION

High activity and specificity of MAbs indicate that they can serve as a basis for development vaccines and preventive medicines.

[Line immunoassay for detection of IgG antibodies to hepatitis E virus (Hepeviridae, Orthohepevirus, Orthohepevirus A)]

INTRODUCTION

The diagnostic efficacy of methods for hepatitis E serodiagnostic varies over a wide range; therefore, the combined use of tests of various formats is recommended. The aim of the research was to develop a test system for the detection of IgG antibodies to hepatitis E virus (HEV) in human serum by linear immunoassay (LIA).

MATERIAL AND METHODS

Serum samples from patients with hepatitis and healthy individuals were tested using commercial enzyme-linked immunosorbent assay systems for the presence of IgG antibodies to viral agents causing hepatitis and other infections associated with liver pathology. Recombinant antigens ORF2 and ORF3 of HEV genotypes 1 and 3 were used. The "RecomLine HEV IgG/IgM" reagent kit (Mikrogen GmbH, Germany) was used as a comparison test system.

RESULTS

The first Russian diagnostic kit "Blot-HEV", designed to detect IgG antibodies to individual HEV proteins in human serum using LIA, was developed. The antigenic base is represented by strips of a nitrocellulose membrane with immobilized recombinant antigens ORF2 (aa 406-660) and ORF3 (aa 1-113) of HEV genotypes 1 and 3, and control antigens in the form of discrete lines. The conjugate was mouse monoclonal antibodies to human class G immunoglobulins labeled with horseradish peroxidase. The chromogen solution contained the 3,3',5,5'-tetramethylbenzidine. A visual and digital recording of results was provided. The analytical sensitivity of the test kit was 0.625 IU/ml for ORF2 antigens and 2.5 IU/ml for ORF3 antigens. The absence of the influence of endogenous interfering substances on the results of the analysis and the absence of cross-reactions with antibodies to hepatitis pathogens of the other etiologies had been shown. The sensitivity of the test system compared to the "RecomLine HEV IgG/IgM" kit was 92%, specificity 97%. Shelf life in condition of storage was determined to be 12 months.

CONCLUSIONS

The developed test can be used to confirm the results of ELISA in laboratory diagnosis of hepatitis E.

[The estimation of the hepatitis E proportion in the etiological structure of acute viral hepatitis in certain regions of of Kyrgyzstan.]

Despite the fact that the Kyrgyz Republic (KR) belongs to the highly endemic regions of the world for hepatitis E, the true extent of the spread of this infection in the country remains poorly understood. It was estimated the prevalence of serological markers of hepatitis E virus (HEV) infection among patients with acute viral hepatitis (AVH) from the regions of the Kyrgyz Republic with a high level of seroprevalence previously established by us. Blood sera samples of hepatitis patients who were admitted to hospitals of Kyrgyzstan in the period 2018-2019 were examined by the enzyme immunoassay method using the kits «DS-ELISA-Anti-HEVIgG» and «DS-ELISA-ANTI-HEV-IgM» (RPC Diagnostic Systems, Russia). IgG and IgM antibodies to HEV were detected in 103 of 344 studied samples (29.9%). Most often, seropositive specimens were detected among people of age groups under 20 and over 40 years old. Hepatitis with the fecal-oral mode of transmission was dominated in the structure of AVH: the specific gravity of hepatitis E was 47.9%, hepatitis A - 35.32%. Markers of mixed infections with other hepatitis viruses have been detected in 40.4% IgM-positive individuals. Thus, high prevalence of serological markers of HEV infection in the territory of Kyrgyzstan during the interepidemic period had been shown. The necessity of including the determination of serological markers of hepatitis E into the algorithm for the comprehensive diagnosis of AVH in patients of all age groups with liver pathology had been confirmed.

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.

DEVELOPMENT OF HEPATITIS E 3 GENOTYPE RECOMBINANT PROTEIN CAPSID OF: CLONING, EXPRESSION, PURIFICATION, EVALUATION OF THE ANTIGENIC PROPERTIES

Aim. The development of the hepatitis E virus (HEV) genotype 3 recombinant capsid protein.Materials and methods. E.coli strains, plasmid vectors, serological and clinical samples, ELISA reagent kits, molecular biological, bioinformatic, biotechnological, biochemical and serological methods.Results. Using viruscontaining material from pigs of Belgorod region (Russian Federation) we made E.coli strains producing recombinant capsid protein, containing C-terminal of viral ORF2 protein fragment fused to E.coli β-galactosidase. Recombinant protein ORF2 had been isolated from the bacterial inclusion bodies and purified by size exclusion chromatography. Antigenic specificity of the recombinant polypeptide was confirmed by ELISA and Western blotting with sera of hepatitis E patients and reference groups (healthy donors, patients with hepatitis A, B, C, infectious mononucleosis, cytomegalovirus infection and HIV-infected patients). Conclusion. HEV genotype 3 ORF2 recombinant antigen had been developed, and the possibility to use it in diagnostic tests had been experimentally shown.

OBTAINING THE RECOMBINANT ORF3 PROTEIN OF HEPATITIS E GENOTYPE 3 AND EVALUATION OF ITS ANTIGENIC PROPERTIES

Aim. Design аис1 construction of the hepatitis E virus (HEV) genotype 3 full-size ORF3 recombimnt polypeptide. Materials and methods. Escherichia coli strains, ptasmid vectors, serologiral and biological amples, molecular biological, bioinformatic, biotechnological, biochemical and serological methods.Results. RNA was isolated from pig fecal extracts collected on Belgorod farms and was used in RT-PCR to obtain the fragment of the orf3 gene of the hepatitis E virus genotype 3. Using A/T-cloning a recombinant plasmid was obtained with insertion of a DNA fragment (230 bp) encoding the N-terminal region of the ORF3 protein. The primary structure of the missing C-terminal region of the ORF3 VGE of the genotype 3 was calculated by bioinformatics methods. Codon optimization of the sequence for biosynthesis in E.coli cells was performed. For constructing the recombinant plasmid a chemically synthesized DNA fragment encoding the fulllength ORF3 protein had been used. E.coli strain producing full-size recombinant protein ORF3 fused to E.coli beta-galactosidase was developed. Recombinant protein ORF3 had been isolated from the inclusion bodies of the E.coli biomass and purified by size exclusion chromatography. Antigenic specificity of recombinant polypeptide had been confirmed in immunochemical reactions (ELISA, Western blot) with sera from patients with hepatitis E and control groups of patients. Conclusion. HEV genotype 3 ORF3 recombinant antigen had been designed, and itfs applicability in diagnostic tests had been experimentally confirmed.

[Oncolytic Properties of a Mumps Virus Vaccine Strain in Human Melanoma Cell Lines]

The oncolytic potential of the attenuated mumps virus (MV) vaccine strain Leningrad-3 (L-3) was evaluated in a panel of four human metastatic melanoma cell lines. The lines were shown to be susceptible and permissive to MV infection. Efficient MV replication led to death of melanoma cells, but the effect differed among the cell lines. Possible mechanisms mediating the selectivity of MV L-3 towards the cell lines were explored. Replicative and oncolytic activity of MV was found to depend on the expression pattern of type I interferon genes. None of the melanoma cell lines showed induction of expression of the total spectrum of genes required to inhibit virus replication. Based on the results, MV L-3 was assumed to be a promising oncolytic agent for human melanoma cells.

The role of regulatory RNAs (miRNAs) in asthma

INTRODUCTION

Recently, a great deal of attention has been paid to the investigation of regulatory functions of microRNA. Currently, many different mechanisms involved in the pathogenesis of asthma are known, but the whole picture of pathogenesis has not yet been studied.

CONCLUSIONS

MicroRNAs play an important role in the regulation of many cellular processes. Undoubtedly, these regulatory molecules are involved in the pathogenesis of asthma, and therefore can be potential targets for treatment.

DESIGN OF HEPATITIS E VIRUS GENOTYPE 1 RECOMBINANT ORF3 PROTEIN BY CODON OPTIMIZATION METHOD

Aim. The development of the hepatitis E virus (HEV) genotype 1 full-size ORF3 recombinant polypeptide. Materials and methods. Escherichia coli strains, plasmid vectors, serological and clinical samples, ELISA reagent kits, molecular biological, bioinformatic, biotechnological, biochemical and serological methods. Results. HEV genotype 1 RNA had been isolated from clinical samples collected in Kyrgyzstan. DNA copy of subgenomic virus RNA had been cloned and used for further development of E.coli strains producing full-size recombinant protein ORF3 fused to E.coli beta-galactosidase. Codons optimization method was used in aim to increase expression level of recombinant protein. Recombinant protein ORF3 had been isolated from the inclusion bodies of the E.coli biomass and purified by size exclusion chromatography. Antigenic specificity of recombinant polypeptide had been confirmed by enzyme-linked immunosorbent assay and Western blotting with the specific sera. Conclusion. HEVgenotype 1 ORF3 recombinant antigen had been designed, and it’s applicability in diagnostic tests had been experimentally confirmed.

DESIGN OF HEPATITIS E VIRUS GENOTYPE 1 RECOMBINANT CAPSID PROTEIN: CLONING, EXPRESSION, PURIFICATION, EVALUATION OF THE ANTIGENIC PROPERTIES

Aim. The development of the hepatitis E virus (HEV) genotype 1 recombinant capsid protein. Materials and methods. Escherichia coli strains, plasmid vectors, serological and clinical samples, ELISA reagent kits, molecular biological, bioinformatic, biotechnological, biochemical and serological methods. Results. Using HEV genotype 1 DNA copy of subgenomic virus RNA we made E.coli strains producing recombinabt capsid protein, containing C-terminal fragment of ORF2 protein fused to E.coli beta-galactosidase. Recombinant protein ORF2 had been isolated from the inclusion bodies of the E.coli biomass and purified by size exclusion chromatography. By Western blotting it had been shown specific interaction of the recombinant polypeptide with anti-HEV IgG from pool of positive sera. Antigenic specificity of the recombinant polypeptide had been confirmed by enzyme-linked immunosorbent assay with sera of hepatitis E patients and reference groups: healthy donors, patients with hepatitis А, В, C, infectious mononucleosis and cytomegalovirus infection, HIV-infected patients. Conclusion. HEV genotype 1 ORF2 recombinant antigen had been developed, and its possible use in diagnostic tests had been experimentally shown.

Phylogenetic comparison of the VP7, VP4, VP6, and NSP4 genes of rotaviruses isolated from children in Nizhny Novgorod, Russia, 2015-2016, with cogent genes of the Rotarix and RotaTeq vaccine strains

Group A rotaviruses (RVA) are one of the leading causes of gastroenteritis in young children worldwide. The introduction of universal mass vaccination around the world has contributed to a reduction in hospitalizations and outpatient visits associated with rotavirus infection. Continued surveillance of RVA strains is needed to determine long-term effects of vaccine introduction. In the present work, we carried out the analysis of the genotypic diversity of RVA strains isolated in Nizhny Novgorod (Russia) during the 2015-2016 epidemic season. Also we conducted a comparative analysis of the amino acid sequences of T-cell epitopes of wild-type and vaccine (RotaTeq and Rotarix) strains. In total, 1461 samples were examined. RVAs were detected in 30.4% of cases. Rotaviruses with genotype G9P[8] (40.5%) dominated in the 2015-16 epidemic season. Additionally, RVAs with the following genotypes were detected: G4P[8] (25.4%), G1P[8] (13%), G2P[4] (3.2%). Rotaviruses with genotypes G3P[9], G6P[9], and G1P[9] totaled 3%. The number of partially typed and untyped RVA samples was 66 (14.9%). The findings of a RVA of G6P[9] genotype in Russia were an original observation. Our analysis of VP6 and NSP4 T-cell epitopes showed highly conserved amino acid sequences. The found differences seem not to be caused by the immune pressure but were rather related to the genotypic affiliations of the proteins. Vaccination against rotavirus infection is not included in the national vaccination schedule in Russia. Monitoring of the genotypic and antigenic diversity of contemporary RVA will allow providing a comparative analysis of wild-type strains in areas with and without vaccine campaign.

[Viral component of the human genome]

Relationships between viruses and their human host are traditionally described from the point of view taking into consideration hosts as victims of viral aggression, which results in infectious diseases. However, these relations are in fact two-sided and involve modifications of both the virus and host genomes. Mutations that accumulate in the populations of viruses and hosts may provide them advantages such as the ability to overcome defense barriers of host cells or to create more efficient barriers to deal with the attack of the viral agent. One of the most common ways of reinforcing anti-viral barriers is the horizontal transfer of viral genes into the host genome. Within the host genome, these genes may be modified and extensively expressed to compete with viral copies and inhibit the synthesis of their products or modulate their functions in other ways. This review summarizes the available data on the horizontal gene transfer between viral and human genomes and discusses related problems.

Viral component of the human genome

Relationships between viruses and their human host are traditionally described from the point of view taking into consideration hosts as victims of viral aggression, which results in infectious diseases. However, these relations are in fact two-sided and involve modifications of both the virus and host genomes. Mutations that accumulate in the populations of viruses and hosts may provide them advantages such as the ability to overcome defense barriers of host cells or to create more efficient barriers to deal with the attack of the viral agent. One of the most common ways of reinforcing anti-viral barriers is the horizontal transfer of viral genes into the host genome. Within the host genome, these genes may be modified and extensively expressed to compete with viral copies and inhibit the synthesis of their products or modulate their functions in other ways. This review summarizes the available data on the horizontal gene transfer between viral and human genomes and discusses related problems.

BALANCE OF Thl/Th2/Th9/Thl7/Th22 CYTOKINES IN POST-OPERATION PERIOD IN PATIENTS WITH MALIGNANT TUMOR OF LIVER

AIM

Evaluate cytokine status in patients with malignant liver cells after surgery.

MATERIALS AND METHODS

33 patients aged 35 to 76 years were included into the study. Blood was obtained before the operation and in the post-operation period: after 6 and 24 hours and at day 7 Cytokine profile (IL-Ib, IL-2, TNF-α, IFN-γ, IL-12p70, IL-4, IL-5,IL-6, IL-10, IL-13, IL-9, I-17a, IL-22) was evaluated using Multiplex- 13 system (Bender MedSystems, Austria).

RESULTS

In patients levels of all the studied cytokines (Thl/Th2/Th9/Thl7/Th22) were already increased before the operations, that gives evidence of the presence of an inflammatory proc- ess connected with activation of immune system effectors.

CONCLUSION

Disbalance of cytokine system helper cells resulting in functional and organic alterations through induction of the "cytokine storm" may aggravate the state of these patients. Further studies on the correction of cytokine system in these patients are thus needed.

[The analysis of sero-prevalence of virus of hepatitis E among patients with HIV-infection and syphilis.]

The infection with hepatitis E virus is one of causes of liver diseases in patients with secondary immunodeficiency, including HIVinfected ones. The study was carried out concerning analysis of rate of detection of serological markers of infection with hepatitis E virus in samples of blood serums of HIV-infected patients and other group of patients with expressed immuno-suppression - patients with syphilis. The sero-prevalence of hepatitis E virus on IgM-antibodies among HIV-infected patients in Moscow made up to 21.7% and 2.9% correspondingly. In the examined group from the Far-East region the highest sero-prevalence of hepatitis E virus on specific IgE-antibodies (73%) is established in the group of patients infected with HIV subtype B. The most frequently IgG and IgM antibodies to hepatitis E virus were detected in HIV-infected patients at the stage of disease 4B. The examined group of patients with syphilis the sero-prevalence of hepatitis E virus made up to 14.7% that significantly surpasses the given indicator in the group of healthy persons (1.7%). The increasing of the level of sero-postivity is demonstrated in the groups of patients with latent syphilis and on the second stage of disease. Therefore, the highest values of sero-prevalence of hepatitis E virus is observed in the groups of HIV-infected patients and patients with syphilis at late stages of disease. In the Russian Federation, the identification of antibodies to hepatitis E virus in HIV-infected patients depends of the region of residence.

[NOVEL APPROACH TO COMPOSITION OF, BACTERIOPHAGE MIXTURES FOR ANTIBACTERIAL THERAPY]

AIM

Evaluate antibacterial activity of an experimental mixture of phages, belonging to several well-studied species.

MATERIALS AND METHODS

The study was carried out using a group of 55 clinical Pseudomonas aeruginosa strains of various origins,- 4 mono-species mixtures of 32 virulent bacteriophages (species phiKZ-, phiKMV-, phiPBl-, PaP3-like phages) and 2 novel phages, phiMK (species PaK-P2) and phiPerm5. Activity of preparations from mono-species mixtures of bacteriophages ofvarious species were compared with activity of 3 commercial mixtures. Standard methods of study of bacteriophages were used: determination of lytic activity by seeding onto bacterial lawns of P. aeruginosa, restriction analysis of phage DNA for confirmation of their be- longing to certain species.

RESULTS

Cumulative activity of 6 mono-species mixtures of virulent phages was shown to be similar to lytic activity of commercial therapeutic mixtures used against P. aeruginosa infections. 54 of 55 strains of clinical isolates of P: aeruginosa showed sensitivity to experimental mixtures composed of mono-species mixtures of bacteriophages. 53 strains were lysed by commercial preparations. Wherein the possibility of accidental inclusion of moderate -bacteriophages in the experimental mixture is excluded.

CONCLUSION

A possibility of creation of highly active therapeutic antibacterial preparations against P. aeruginosa using mono-species mixtures of 6 species of lytic bacteriophages is shown Use of such a mixture in therapy of lung infections reduces the risk of emergence of bacterial strains with increased virulence and patho- genicity during prolonged administration.

In vitro studies of the antiherpetic effect of photodynamic therapy

The number of viral infection cases in the Department of Gynecology and Obstetrics has tended to increase over last few years. Viruses form herpesvirus and cytomegalovirus families are associated with an increased risk for recurrent pregnancy loss. Photodynamic therapy (PDT) is a promising new approach to treat viral infections in which viral particles are inactivated. It exhibits great therapeutic potential, particularly among this group of patients. This study examined the use of PDT to treat herpesvirus infection (HVI) using an in vitro model. In this study, we used the Vero сell lineage as a suitable model of HVI, strains of HSV-1 (strain VR-3) and HSV-2 (strain MS) obtained from The National Virus Collection (London, UK), the photosensitizer Fotoditazine (Veta-Grand, Russia), an AFS physiotherapeutic device (Polironic Corporation, Russia). Laser light irradiation and the photosensitizer had different cytotoxic effects on the Vero cell cultures depending on the doses used. The optimal laser light and photosensitizer doses were determined. PDT had an antiviral effect on an in vitro model of HVI in cell culture. PDT has been shown to be effective treatment for HVI in vitro, leading to a reliable decrease of viral titer.

[EFFECTIVENESS OF FULLERENE-(TRIS-AMINOCAPRONIC ACID) HYDRATE IN THE MODEL OF EXPERIMENTAL VIRAL-BACTERIAL PNEUMONIA OF MICE]

AIM

Study the effectiveness of the substance and various drug formulations of fullerene-(tris-aminocapronic acid) hydrate (FTAAH onwards) in the model of experimental viral-bacterial pneumonia of mice.

MATERIALS AND METHODS

BALB/c mice were infected with influenza virus A/California/04/2009 and subsequently infected with Staphylococcus aureus. The animals were treated after viral infection with the substance and various drug forms of FTAAH, as well as comparative preparations--oseltamivir and arbidol. Therapy effectiveness was evaluated by clinical indicators (survival, lifespan, animal mass decrease reduction), virological (virus titer), microbiological (density of bacteria in lungs) parameters, confirmed by pathomorphological characteristics of lungs.

RESULTS

FTAAH therapy in injectable form was effective in the model of a combined viral-bacterial pneumonia of mice by all the studied criteria: treatment increased mice survival, reduced the decrease of their body weight, resulted in a reduction of virus titers and density of bacteria in lungs, that correlated with the data from morphological study and signs of bronchopneumonia resolution in mice. FTAAH therapy in rectal form depended on animal infection schemes, as well as preparation dose, increasing with its increase.

CONCLUSION

FTAAH substance is effective in the model of experimental viral-bacterial pneumonia of mice.

[VARICELLA ZOSTER VIRUS AND DISEASES OF CENTRAL NERVOUS SYSTEM VESSELS]

Systemized data on epidemiology, pathogenesis, clinical manifestation, diagnostics and therapy of VZV-vasculopathy--a disease, occurring due to damage of arteries of the central nervous system by Varicella Zoster virus, are presented in the review. A special attention in the paper is given to the effect of vaccine prophylaxis of chicken pox and herpes zoster on the frequency of development and course of VZV-vasculopathy.

[POSSIBILITY OF USING NESTED POLYMERASE CHAIN REACTION FOR DIAGNOS- TICS OF DISEASES CAUSED BY VARICELLA ZOSTER VIRUS]

AIM

Demonstrate the possibility of using nested PCR method for determination of Varicella Zoster virus (VZV) in clinical samples of peripheral blood of patients.

MATERIALS AND METHODS

Material from 35 patients with clinical manifestations of herpes zoster and control group of 20 healthy donors was used in the study. Monocyte fraction of venous blood cells, pretreated with heparin, was isolated by centrifugation in ficoll-verografin density gradient, total DNA was then isolated from cells by phenol-chloroform extraction with subsequent precipitation with alcohol. Polymerase chain reaction was carried out in thermocyclers Tercyc and TProfessional Gradient (Biometra), amplified DNA was analyzed by electrophoresis on 1.6% agarose gel in the presence of ethidium bromide.

RESULTS

Data on detection of viral DNA in blood monocytes in 17 (49%) of ill patients, as well as in 1 (out of 20 in control group) practically healthy donor were obtained. A possibility of a subclinical reactivation of the virus is discussed in the latter case.

CONCLUSION

A possibility of viral DNA determination in monocytes of patient blood without using expensive equipment is shown, that could find application in clinical practice, especially for diagnostics of patients with non-characteristic clinical manifestations, as well as patients with subclinical forms of the disease.

[The study of the antiviral activity of polyelectrolytes with respect to the influenza virus]

It is well known that polyelectrolytes (PE) have a damaging effect on the secondary structure of the proteins and enzymes. It is also known that some PEs exert an immunostimulating action on T- and B-lymphocytes. However, currently, almost nothing is known about the impact of the PE of the viral proteins and viral envelope. Therefore, a detailed study of the mechanisms of the antiviral action of various polyelectrolytes would create the scientific-practical base for the construction of the antiviral drugs on the polyelectrolyte basis. In these works, for the first time the influence of PE polystyrene sulfonate (PSS) with varying degrees of polymerization and polyallylamin (PAA) and with molecular mass 6 and 8 kDa on the infectivity of different strains of the influenza virus was studied. It was shown that the expressed antiviral action PSS with degree of polymerization-8 (ETS-8) and PAA (6 kDa) against the influenza viruses was characterized by a significant reduction in the infectious titer of the virus. It was determined that the span of the nontoxic concentrations for the ETS-8 was 1-40 mM; for PAA (6 kDa), 1-40 μM, with IC50 = 3.8 ± 0.19 mm and 1.8 ± 0.09 μM, respectively. For the first time the impact of the PE on the structural-functional state of the viral membrane was assessed on the basis of monomolecular monolayers used as models of cell membranes.

[The prevalence of the human rhinoviruses and coronaviruses circulating in the Moscow region during 2007-2012]

The rhinoviruses and coronaviruses are the most common causative agents of the acute upper respiratory tract infection in humans. They include several species that vary in the pathogenicity, some causing severe respiratory tract diseases. In this work, the species prevalence of rhinoviruses and coronaviruses was studied in 92 virus-positive clinical patients that were collected at the area of the Moscow region during the period from 2007 to 2012. Using the real-time PCR the virus circulation has been established for all species common in humans, including three rhinoviruses, HRV A, HRV B, and HRV C, and four coronaviruses, HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1. For eight patients, the identity of the rhinoviruses, including 4 cases of HRV-C, 3 cases of HRV-A, and a single case of HRV-B, was corroborated using partial sequencing of the 5 non-coding regions and phylogenetic analysis. The viruses of HRV-C, HCoV-NL63, and HCoV-OC43 were prevalent in children with severe respiratory diseases.

[Evaluation of real-time multiplex PCR effectiveness for group a rotavirus genotyping]

AIM

Evaluate resolution and diagnostic significance of real-time multiplex PCR (MP RT-PCR) as a platform for group A rotavirus G/P genotyping test-systems.

MATERIALS AND METHODS

Primer and DNA probe construction for an experimental test-system based on MP RT-PCR was carried out by using specialized PC programs and sequence databases GenBank NCBI, EMBL Nucleotide Sequence Database etc. The experimental genotyping test-system was tested using 116 clinical samples with confirmed rotavirus infection and 14 biosamples negative for group A rotavirus RNA. Selective sequencing of VP7, VP6, VP4 gene mark-erloci was carried out as a reference method forverifying determination of rotavirus genotype.

RESULTS

Specific interaction between primers and DNA probes with genotype-specific loci of retrovirus genome segments and a lack of false-negative signals, complete match ofgenotyping results obtained by MR RT-PCR and sequenc- ing methods were established.

CONCLUSION

The resolution of MP RT-PCR methods allows designing test-systems that can confidently identify rotavirus genotypes with effectiveness of 90% and above.

[Intestine microbiota and allergic diseases]

In industrialized countries an increased number of diseases due to immune system disorders including connected with allergy is noted. Allergic diseases generally proceed against the background of various common inflammatory diseases arising in childhood. The role of intestine microflora in its interaction with immune system and defining factors in allergization of children are actively studied. A decrease of risk of allergy development later in life for children who had grown up in the countryside was shown to be possibly related with microorganisms present in food. Thus the positive potential of farms is currently examined as a result of innate immunity activation by using microbial components. Acinetobacter lwoffii F78 isolated from cowsheds is able to protect mice from experimental allergy by activating Th1-polarization program of dendritic cells. Moreover, an important role in pathogenesis of allergic diseases belongs to mast cells. Probiotic lactobacilli may weaken activation of mast cells and release of inflammation mediators connected with allergic reactions. The ability of intestine microflora to influence immune response resulted in novel approaches in therapy that use these differences in microbiota for therapy and prophylaxis in allergy patients. And therefore on the basis of "hygiene hypothesis" of allergy emergence, a consideration is expressed that early manipulation with intestinal microbial communities may offer a new strategy of allergic sensibilization prevention.

[Cell analogs of viral proteins]

Horizontal transfer of genes between viruses and their hosts played an important role in the evolution of various eukaryotes including contemporary mammals as well as the pathogens themselves. Elements of viruses of various types can be found in the genome of animals. Endogenous retroviral elements composing up to 8% of human genome length not only determine its high flexibility and rapid adaptation potential. Many of virus genes such as Fv1, Lv1, Lv2 being analogues of capsid and other proteins determine effective suppression of viral replication after cell penetration by the causative agent. Introduction of these elements into genome of a wide variety of animals from fish to primates could have taken place against the background of global natural cataclysms of viral origin. Integration of retrovirus genes coding surface glycoproteins with immunosuppressing domains into genetic apparatus of animals served as an impetus to the development of viviparity and spread ofplacental mammals. Their cell analogs syncytins perform a dual function: take direct part in the formation of syncytiotrophoblast layer of placenta and ensure tolerance of immune system of mother to embryo. The acquisition of cell genes by viruses also played an important role in their evolution: various interleukins and other modulators of immune response introduced into viral genome from cell genetic apparatus became one of the most important factors of pathogenicity of a wide variety of causative agents including poxviruses, cytomegalovirus, Epstein-Barr virus and many others. Evolutionary pathways of the virus and host are thus inseparable from each other, and character of one of these directions is largely dictated by the vector of another.

[Rubella virus genetic determinant of attenuation]

Vaccination is the most effective and available way to prevent Rubella. Presently, 9 vaccine strains were registered. Nevertheless, the molecular mechanisms of the attenuation were poorly elucidated for the rubella virus. However, the study of these mechanisms identifying genotypic and phenotypic markers of attenuation, which together with sequence analysis could be used for the genetic stability control of vaccine strains, is still of current interest. Common trends of genetic changes in the process of adaptation to cold were found due to comparison of nucleic acid and amino acid sequences of the Russian strain C-77 with corresponding positions of the known rubella virus strains and its wild type progenitors, if available.

[Umifenovir (Arbidol) efficacy in experimental mixed viral and bacterial pneumonia of mice]

Pneumonia often occurs as a secondary infection after influenza and accounts for a large proportion of the morbidity and mortality associated with seasonal and pandemic influenza outbreaks. The efficacy of umifenovir (Arbidol) was investigated on a murine model of S. aureus pneumonia following A/California/04/2009 (H1N1) influenza virusinfection. Oral treatment with umifenovir (40 and 60 mg/kg/day) in all the contamination schemes increased the survival rate in the mice from 0% to 90% and lowered the animal weight loss. The umifenovir treatment also decreased the virus titer by ≥ 2 logs and the viable bacteria counts in the lungs of the mice. The lungs of the mice treated with umifenovir had less severe histopathologic lesions compared to the control group.

[Anti-herpetic effect of photodynamic action in an in vitro experiment]

AIM

Evaluation of photodynamic therapy (PDT) in vitro antiviral effect directly on the herpes simplex virus (HSV) as well as on virus infected cells.

MATERIALS AND METHODS

HSV infected Vero cell culture; HSV-1 (VR-3 strain) and HSV-2 (MS strain) were used. Fotoditazin preparation (chlorin E6 derivative) was used as a photosensitizer. AFS physiotherapy apparatus was used for laser irradiation. Experiment variants: study of direct and mediated photodynamic effect on virus-containing fluid (HSV-1 and HSV-2) and on non-infected cell culture; evaluation of anti-herpetic effect of PDT and study of the effect on the newly produced HSV-1 progeny were carried out within the developed experiment scheme.

RESULTS

A scheme of experiment conduction for study of mediated photodynamic effect of HSV was developed. A significant reduction of virus titers for more than 2 orders of magnitude (100-1000 times) was detected. Optimal concentration of photosensitizer and laser irradiation dose that results in reduction of HSV-1 titers by 1000 and more times (1.5 - 2.5 orders of magnitude) and reduction of HSV-2 titers by 10 and more times (1.5 order of magnitude) were determined.

CONCLUSION

The data obtained will help selection of adequate scheme of PDT conduction for patients with recurrent herpes virus infection including patients with recurrent miscarriage.

[The effectiveness of non-invasive lung ventilation in lateral amyotrophic sclerosis]

OBJECTIVE

Lateral amyotrophic sclerosis (LAS) is a very severe neurodegenerative disease with progressive course and terminal respiratory insufficiency. Non-invasive lung ventilation (NLV) is a main method of treatment. We studied the effectiveness of NLV in LAS and assessed patient's adaptation to NLV, life expectancy, compliance and an effect of NLV on spirometric parameters.

MATERIAL AND METHODS

NVL was administered to 28 patients, mean age 56.2 ± 9.4 years, including 10 patients with bulbar onset and 16 with spinal onset. The rapid progression of the disease was observed in 15 patients, slow progression in 13 patients.

RESULTS AND CONCLUSION

NLV used in regime S extended the life of patients, in particular, patients with spinal onset. The adjustment to the NLV device plays a crucial role. Two types of the adjustment were established: gradual (13 patients) and accelerated (4 patients). The causes of the latter were not found. It should be emphasized that several questions related to the details of NVL regime should be specified in further research in the field.

[The role of immunodeficiencies in development of complications during vaccination of children with BCG vaccine]

AIM

Study of the interrelation between the presence of immune deficiency and development of complications during vaccination of newborns with BCG vaccine.

MATERIALS AND METHODS

In 24 children with complications of vaccine process in the form of cold abscess and lymphadenitis indicators of lymphocyte subpopulation levels were studied by flow cytofluorimetry on Beckman Coulter cytofluoriemter by using monoclonal antibodies with markers CD45+CD3+ - T-cell, CD45+CD3+CD4+ - T-helpers, CD45+CD3+CD8+ - T-supressors-cytotoxic killers, CD45+CD3 CD16+CD56+ - natural killers, CD45+CD3-CD19+ - B-lymphocytes. The level of IgG, IgA, IgM in sera was determined by immune diffusion method in agar by Mancini.

RESULTS

In 4 children selective deficiency of IgA, in 5 - hyper-IgM syndrome was detected, which is an innate immunodeficiency and is characterized by the lack of sera IgA, reduction of IgG level and increase of IgM. In 9 children a reduction of CD16+ natural killer lymphocytes was detected, in some cases combined with a reduction of CD8+ T-supressors-cytotoxic killers.

CONCLUSION

The reason of development of complications during BCG administration is the presence of immunodeficiency in children. In these children severe course of the vaccine process, presence of axillary lymphadenitis was observed, therapy of these children continued from 4 to 6 months.

[Evaluation of expression of innate immunity component genes in mice leukocytes under the effect of synthetic ligands in vivo]

AIM

Study the effect of synthetic ligands on the dynamics of TLR9 and BD-2 gene expression in vivo.

MATERIALS AND METHODS

Synthetic ligands were used whose sequence was homologous to DNA and RNA human viruses. At days 1, 7 and 28 blood sampling from BALB/c line mice was carried out. Determination of level of TLR9 and BD-2 gene expression was evaluated by using RT-PCR in real-time mode.

RESULTS

The following ligands had the maximum effectiveness: tgg-ccc-ccc-ttg-tgg-acc-gg, ccg-gtc-cac-aag-ggg-ggc-ca and tcg-tcg-ttt-tgt-cgt-tgt-cg. At day 1 after the administration of ligands a significant increase of TLR9 gene expression was observed (62, 18 and 13 times, respectively), but at the same time defensin gene expression changed insignificantly.

CONCLUSION

The approach developed may be used to evaluate the effect of these preparations on the system of innate immunity, namely TLR activation.

[Preclinical studies of an adsorbed diphtheria-tetanus-pertussis vaccine (ADTP-vaccine) with acellular pertussis component]

AIM

Evaluate standardness of antigenic composition of pertussis component, completeness of sorption of pertussis, diphtheria and tetanus components, specific activity and safety of experimental series ofADTP-vaccine with acellular pertussis component (ADTaP-vaccine).

MATERIALS AND METHODS

The content of separate antigens (pertussis toxin, filamentous hemagglutinin and agglutinogens 1, 2, 3) in samples of acellular pertussis component of ADTaP-vaccine and completeness of sorption of pertussis component of ADTaP-vaccine were evaluated by using enzyme immunoassay. Completeness of sorption of diphtheria and tetanus components were determined in flocculation reaction and antitoxin-binding reactions, respectively. Protective activity ofADTaP-vaccine was studied in model ofmeningoencephalitis development in mice infected with Bordetella pertussis (strain 18323) neurotropic virulent culture, protective activity oftetanus component - by survival of mice after administration of tetanus toxin, protective activity of diphtheria component - by survival of guinea pigs after administration of diphtheria toxin. Safety of preparations was evaluated in tests of acute and chronic toxicity with carrying out pathomorphologic studies including immature animals.

RESULTS

All the studied experimental series ofADTaP-vaccine were standard by content of separate antigens of pertussis microbe. All the ADTaP-vaccine components were completely sorbed on aluminium hydroxide gel. By protective activity ADTaP preparations satisfied the WHO requirements. The preparations were non-toxic in acute and chronic toxicity and did not induce pathomorphologic changes including immature animals.

CONCLUSION

Experimental samples of ADTaP-vaccine by specific activity and safety satisfied WHO requirements.

[Mechanisms of retroviral immunosuppressive domain-induced immune modulation]

Immunosuppressive domains (ISD) of viral envelope glycoproteins provide highly pathogenic phenotypes of various retroviruses. ISD interaction with immune cells leads to an inhibition of a response. In the 1980s it was shown that the fragment of ISD comprising of 17 amino acids (named CKS-17) is carrying out such immune modulation. However the underlying mechanisms were not known. The years of thorough research allowed to identify the regulation of Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR cellular pathways as a result of ISD interaction with immune cells. By the way, this leads to decrease of secretion of stimulatory cytokines (e.g., IL-12) and increase of inhibitory, anti-inflammatory ones (e.g., IL-10). One of the receptor tyrosine kinases inducing signal in these pathways acts as the primary target of ISD while other key regulators--cAMP and diacylglycerol (DAG), act as secondary messengers of signal transduction. Immunosuppressive-like domains can be found not only in retroviruses; the presence of ISD within Ebola viral envelope glycoproteins caused extremely hard clinical course of virus-induced hemorrhagic fever. A number of retroviral-origin fragments encoding ISD can be found in the human genome. These regions are expressed in the placenta within genes of syncytins providing a tolerance of mother's immune system to an embryo. The present review is devoted to molecular aspects of retroviral ISD-induced modulation of host immune system.

[Prevalence, features of circulation, and diversity of human parechoviruses in Nizhny Novgorod]

A total of 5230 specimens from children with gastroenteritis collected in Nizhny Novgorod in 2006-2010 were screened for human parechoviruses (HPeV). HPeV were observed every year with mean frequency of 6.16%. The majority of HpeV (65.83%) was detected in children younger than 3 years. The typing of 71 detected HPeV with the use of partial sequencing of the VP3-VP1 region revealed the presence of HPeV1 (91.55%), HpeV6 (5.63%), HPeV3 (3.08%), HPeV4 (1.54%). HPeV1B was predominant among HPeV1, HPeV1A was identified rarely. Six stains of HPEV1 formed separate phylogenetic cluster, had sequence gomology with HPEV1A or HPeV1B not more than 88% and could be characterized as members of a separate genotype HPeV1.

[Experience of application of multiplex qPCR for differential diagnostics of intestinal viral infections]

AIM

Evaluate the effectiveness of multiplex reverse transcription (RT) and polymerase chain reaction with fluorescence detection in real time mode (qPCR) methods for differential detection of 11 groups of intestine viruses (adenoviruses, enteroviruses, polioviruses, hepatitis A and E viruses, group A and C rotaviruses, orthoreoviruses, noroviruses, sapoviruses and astroviruses) in various biological samples.

MATERIALS AND METHODS

Panels of virus isolates and clinical samples characterized by reference methods were used to evaluate sensitivity of detection of various intestine viruses. Nucleic acids were isolated from study samples and multiplex RT and qPCR were carried out.

RESULTS

Sensitivity of laboratory reagent kit (LRK) when compared with results obtained from reference methods was 100% for rotavirus A, adenovirus, enterovirus and norovirus, 88.9% for hepatitis E virus and 92.3% for hepatitis A virus, and diagnostic specificity - 99.4%. During analysis of 697 clinical samples from patients with acute intestine infection symptoms nucleic acids of various intestine viruses were isolated in 71.7%.

CONCLUSION

Multiplex qRT-PCR was shown as an effective method of etiologic diagnostics of an intestine viral infection. Use of LRK was demonstrated to establish etiology of intestine diseases in 63 - 72% and in children with watery diarrhea - in approximately 90% of cases.

[Economic effectiveness of vaccination against rotavirus infection in the Russian Federation]

AIM

Perform pharmacoeconomic analysis of the effectiveness of implementation of vaccination program against rotavirus infection in the Russian Federation.

MATERIALS AND METHODS

Cost-benefit analytical method was used for the evaluation of economic effectiveness of vaccination against rotavirus infection in the Russian Federation. The number of early vaccinated--1 800 000 individuals, the number of rotavirus enteritis cases in 0 - 5 age cohort--166 215, were determined. The effectiveness of vaccination against rotavirus gastroenteritis was adopted from ATP (according-to-protocol) clinical trial data and was 83.8% cases at a 95% vaccination level. The cost of a case of rotavirus infection according to calculations in the Russian Federation is 17 394 RUB (Russian rubles), and the cost of vaccination of 1 child--1000 RUB.

RESULTS

The cost of realization of program of vaccination against rotavirus infection would be 1.7 billion RUB per year. The number of prevented cases of rotavirus infection per year in the cohort of children aged up to 5 years would be 148 114. Net benefit of vaccination of newborn children in the Russian Federation would be 866 million RUB.

CONCLUSION

Implementation of program of vaccination against rotavirus infection in the Russian Federation would promote the decrease of morbidity and economical efficiency. The cost of vaccination program is 1.5 times less than the amount of expenses related to infection.

[Economical effectiveness of vaccination of cohort of children aged 2 years against chickenpox in the Russian Federation]

AIM

Perform calculation of the economical effectiveness of realization of a program of vaccination of children aged 2 years against chickenpox (CP) in the Russian Federation.

MATERIALS AND METHODS

Data of Federal service on customers rights protection and human well-being surveillance on evaluation of morbidity and losses caused by CP in the Russian Federation in 2008 - 2010 were used. A cohort of children (1 760 000) aged 2 years subject to vaccination against CP in 2011, evaluation of cost of 1 case of the infection, the amount of losses per vaccination of 1 child were approximately determined; analysis of prevented losses by implementation ofvaccination program by using mathematical modeling methods was performed.

RESULTS

Without vaccination program in the Russian Federation the cost of losses per 1 case of CP related to hospitalization and outpatient visits as well as temporary disability of one of the parent in various age groups was: for children aged 1 - 2 years--8 333 RUB (Russian rubles), 3 - 6 years--21 171 RUB, 7 - 14 years--21 295 RUB. The cost of vaccination against CP of 1 child including 2 doses of vaccines with physician examination and vaccination procedure would be 1600 RUB. In the case of realization of vaccination program against CP in 2011 of children aged 2 years its cost would be 2 488.9 million RUB. Cost prevention already exceeds the cost of vaccination in 1 age cohort of children at year 2 and in 5 years the amount of prevented losses would exceed 15 billion RUB per 1 vaccinated cohort and would continue to increase steadily.

CONCLUSION

The performed calculations show that vaccination against CP in the Russian Federation is a highly efficient investment. Self-sufficiency of a program implemented in 2011 may be obtained already at the start of year 2 after the realization and by 2016 the net economical benefit would be around 8 milliards RUB.