Long-Term Maintenance of the Functional Changes Induced by Influenza A Virus and/or LPS in Human Endothelial ECV-304 Cell Sublines.

Influenza A virus and secondary bacterial infection may have remote effects in the form of cardiovascular complications or fibrosis in different organs. However, the mechanisms governing the development of complications remain poorly studied. The present work reports the comparative assessment of the functional changes which take place in human ECV-304 endothelial cell sublines obtained previously by the long-term culturing of cells after exposure to varying infectious doses (IDs) of influenza A virus, and/or bacterial lipopolysaccharide (LPS). It has been demonstrated that, in the course of long-term culturing (six passages) after exposure to pathogenic agents (influenza virus and/or LPS), endothelial cells maintain changes in their migratory activity, permeability, and expression of mRNA for cytokines TNFα and TGFß (along with the changes in their proliferation activity, which has been demonstrated earlier). The pattern of changes depended on the type of the agent (agents) to which the cells were exposed. The differences in migratory activity (which was at its maximum 4 h after wounding) between the cell sublines at the sixth passage correlated with the differences in their proliferation activity at the first passage (proliferation data were obtained previously). In particular, an increase in migration and proliferation was observed in the sublines exposed to low virus doses (ECV-1ID), as well as exposed to LPS (ECV-LPS), while the suppression of migration and proliferation was observed in the subline exposed to high virus doses (ECV-1000ID). In the ECV-1ID, ECV-LPS, and most notably in ECV-1ID + LPS sublines, we detected an increase in the expression of mRNA for cytokines TNFα and TGFß, which, however, didn't lead to the induction of apoptosis. We have also demonstrated an increase in cell permeability in the analyzed sublines, which was indicated by a decrease in the expression of the mRNAs for the genes encoding occludin and ZO-1, the tight junctions proteins . This paper also reports an evaluation of the effects of the antiviral preparations rimantadine and alpisarin on the functional state of cell sublines. As a result, it has been demonstrated that these drugs may be able to prevent the development of the pathological changes caused by influenza A virus and/or LPS in endothelial cells. The results obtained in the present work may be of use when studying the mechanisms of development of the influenza A virus and secondary bacterial infection complications.

[Etiological structure of influenza and other ARVI in St. Petersburg during epidemic seasons 2012-2016.]

The etiological structure of influenza and other acute respiratory viral infections including their rate of incidence in St. Petersburg and Leningrad region during 4 epidemic seasons has been studied. Seasonality of some respiratory viruses was shown and peaks of circulation of RSV, adenovirus, parainfluenza viruses, rhinovirus, bocavirus, metapneumovirus and coronavirus were marked. The interference of influenza A viruses and RSV, RSV and rhinoviruses was highlighted. A high incidence of adenovirus infection in organized communities and RSV infection in children was revealed.

GENETIC AND ANTIGENIC CHARACTERISTICS OF RESPIRATORY SYNCYTIAL VIRUS STRAINS ISOLATED IN ST. PETERSBURG IN 2013-2016.

Antigenic and genetic characteristics of Russian RSV isolates are presented for the first time. Of the 69 strains isolated in St. Petersburg, 93% belonged to the RSV-A antigenic group. The antigenic variations in the F-protein RSV were analyzed using a panel from 6 monoclonal antibodies by the method of micro-cultural ELISA. Depending on the decrease in the effectiveness of interaction with monoclonal antibodies (relative to the reference strain Long), RSV-A isolates were divided into 4 antigenic subgroups. The results of 24 isolates sequencing showed that more than 60% of them had substitutions in significant F-protein sites compared to the ON67-1210A reference strain of the current RSV genotype ON1/GA2. The most variable were the signal peptide and antigenic site II. When comparing the results of ELISA and sequencing, it was not possible to identify any specific key substitutions in the amino acid sequence of the F-protein that affect the interaction of the virus with antibodies. The nucleotide sequence of the F-gene from 19 of the 24 characterized isolates was close to that of ON67-1210A reference virus and was significantly different from RSV-A Long and A2 viruses. A separate group consisted of 5 strains, in which the F-protein structure was approximated to RSV Long.

GENETIC DIVERSITY OF ADENOVIRUSES CIRCULATING AMONG THE MILITARY IN THE NORTH-WEST REGION.

The contribution of adenovirus (AV) infections to the overall structure of acute viral respiratory infections among young people of draft age can reach as high as 64.6%. Wide dissemination, the incidence of AV-associated pneumonias and lethal outcomes in the case of some complicated infections illustrate the urgency of studying the antigenic diversity of AVs circulating among the military. 991 nasopharyngeal swabs from patients hospitalized in military health facilities with symptoms of acute respiratory infections from 2014 to 2017 were detected by real-time PCR. Sanger sequencing was performed using forward and reverse primers matching the fiber gene. AVs were detected in 326 samples. In 80 of those, AVs were present in combination with other respiratory viruses, as follows: 26 with respiratory syncytial viruses (RSV), 49 with rhinoviruses, 2 with bocaviruses, 1 with RSV and rhinovirus, 1 with parainfluenza virus, and 1 with metapneumovirus. 31 samples were sequenced. Thirty AVs belonged to group E (serotype 4), and 1 AV belonged to group B (serotype 7).

[THE APPLICATION OF DOT-TECHNIQUE FOR DETECTING ANTIGENS OF ADENOVIRUS IN CLINICAL SAMPLES].

The article substantiates possibility of application of point enzyme-linked immunosorbent assay (dot-technique) for detecting viral antigens in samples from patients. To diagnose adenovirus infection conjugate of virus-specific monoclonal antibodies and peroxidase of horse-radish were used The chromatographic rectification of conjugate from free peroxidase permits diminishing background coloring of nitrocellulose membrane and therefore to increase sensitivity. The application of direct conjugates on the basis of virus-specific monoclonal antibodies increases specifcity of dot-technique and significantly shortens time period of analysis. As in case of application of direct conjugates on the basis of polyclonal serum, samples from patients require preliminary processing with detergent for preventing non-specific reactions. The dot-technique demonstrates good coincidence with data of polymerase chain reaction and after clinical trials it can be used in diagnostic of human viral infections.

INFLUENCE OF INFLUENZA A VIRUS AND BACTERIAL LIPOPOLYSACCHARIDE ON PROLIFERATION AND GENE EXPRESSION OF CYTOKINES AND OTHER CELLULAR FACTORS IN CELLS OF ESTABLISHED ENDOTHELIAL CELL LINE ECV-304.

Change of state of endothelial cells occurs under the action of viral infection and bacterial lipopolysaccharide (LPS) that leads to cell dysfunction. Therefore, the aim of the current study was to investigate the effect of LPS from Escherichia coli and influenza A virus on proliferative activity of human endothelial cells (ECV-304) and gene expression of several cytokines and cellular factors: TNFá, TGFâ, IFN-ã, MMP-9, NF-êB, Rho A, eNOS and iNOS. It was found that ECV-304 cells once infected with very low infectious doses of influenza virus acquire the ability to long-term active proliferation (over 8 passages). Addition of LPS E. coli reduced the virus-stimulated cell proliferation. It was shown that influenza virus and LPS can affect on gene expression of cytokine and other cellular factors. When endothelial cells had been infected with influenza A virus in the presence of LPS, there was a significant increase in the expression of several genes and replacement of some genes expression on the expression of other genes. Expression of MMP-9 gene was inhibited in the case of separate exposure to the virus and LPS, but it was significantly increased during the first day under the adding of the virus and LPS together, as well as the activity of the IFN-ã gene; gene of TNFá was active for only 1­3 days whereas genes expression of other factors (TGFâ, eNOS, iNOS, NF-êB and Rho A) increased significantly at the 5th day as in the case of adding only LPS. Thus, the change of physiological state of endothelial cells occurs in the presence of influenza A virus and LPS and it can be caused during different time periods (as well as by varying degrees of virus infection of cells) by different cellular factors and possibly with involvement of different signaling pathways.

CHRONIC HEPATITIS WITH DOUBLE B/C INFECTION: VIROLOGICAL, CLINICAL, MORPHOLOGICAL CHARACTERISTICS.

AIM: To estimate the r, virological and clinical characteristics of chronic viral hepatitis (CVH) with double B/C infection. MATERIALS AND METHODS: We examined 282 patients with CVH. Genomes of hepatitis B virus (HBV) and hepatitis C virus (HCV) were studied by PCR in blood and liver (AmpliSens HBV and Amplisens HCV Russia), nuclear proteins (HBcorAg HBV and NS3 HCV) were determined by immunohistochemical method (Novocastra, UK), HBVgenome was sequenced by the Sanger method using ABI prism BigDye Terminator v3.1 kits and ABIPRISM 3100 analyzer (AppliedBiosystems, USA). Indices of histological activity (HAI), fibrosis, and portal vein (PV) congestion index (CI) were calculated by formula CI=SBB/LB V where S is P V cross section area in cm2 and LB V - linear blood flow velocity in cm/s (Vivid Pro- 7 apparatus, USA). RESULTS: CVH with double B/C infection was diagnosed in 85 (30.1%) patients including 44.7% with viral genomes and proteins in the live; 42.4% with HCVviremia, and 12.9% with HBJV/HCVviremia. Maximum CVH activity was documented in patients with latent HBV/HCVviremia (ALT 157.2±59.2 U/, HAI 11.6±1.3,fibrosis 2.8±0.7, C1 0.059±0.005); it was minimal inpatients.without viremia (Alt 76.25±63.0 U/I, HAI 6.7+-0.6,fibrosis 1.7±0.5, CI 0.042±0.001;p <0.05). Patients with latent HBV infection had precore/ore and pres/s mutations in HBVgenome and cytoplasmic localization ofHBcorAg. CONCLUSION: Double B/C infection was diagnosed in 30.1% of the patients with CVH dominated by HCV Patients with latent HBVhadprecore/ore and pres/s mutations. The highest intensity of hepatic cellular inflamation,fibrosis, and PV congestion was associated with HBV/HCV viremia and the lowest with intrahepatic localization of both viruses.

[Clinical and laboratory presentation of the influenza A (H1N1pdm 2009) in children and adults during the period of 2009-2013 in St. Petersburg].

Comparative analysis of the clinical laboratory data from 419 children and 468 adults hospitalized during the pandemic of A (H1N1pdm 2009) and pre- and post-pandemic periods (2010-2013) showed that the clinical presentation of the pandemic influenza in patients of all ages is generally typical for influenza, and its character is determined by the degree of involvement of lungs in the process. Besides, the incidence of pneumonia in adults is statistically significantly higher than in children. During all compared periods hyperthermia (≥ 39 degrees C), hemorrhagic and dyspeptic syndrome were observed. Some differences in the main clinical manifestations of pneumonia in recovered patients and patients who died of the severe pandemic influenza were observed. The regularities of the cytokine reactions depending on the intensity of intoxication and occurrence of complications were determined in patients of all ages. Medical efficacy of inclusion of antiviral chemotherapeutic agents into complex influenza treatment was proved.

[THE COMPARATIVE ANALYSIS OF EFFECTIVENESS OF QUICK TESTS IN DIAGNOSTIC OF INFLUENZA AND RESPIRATORY SYNCYTIAL VIRAL INFECTION IN CHILDREN].

The analysis was implemented concerning diagnostic parameters of commercial quick tests (immune chromatographic tests BinaxNOW Influenza A&B and BinaxNow RSV Alere, Scarborough Inc., USA) under detection of antigens of influenza virus A and respiratory syncytial virus in clinical materials. The polymerase chain reaction in real-time and isolation ofviruses in cell cultures. The analysis of naso-pharyngeal smears from 116 children demonstrated that sensitivity and specifcity of detection of influenza virus A using device mariPOC in comparison with polymerase chain reaction made up to 93.8% and 99.0% correspondingly at total concordance of results of both techniques as 98.3%. At diagnosing of respiratory syncytial virus using device mariPOC parameters made up to 77.3%, 98.9% and 862% as compared with polymerase chain reaction. The sensitivity, specificity and total concordance of results of immune chromatographic tests BinaxNOW in comparison ofpolymerase chain reaction made up to 86.7%, 100% and 96.2% correspondingly at detection of influenza virus A and 80.9%, 97.4% and 91.6% correspondingly at detection of respiratory syncytial virus. In comparison with isolation technique in cell cultures sensitivity of system mariPOC and immune chromatographic tests proved to be in 1.3-1.4 times higher at detection of influenza virus A and in 1.7-2 times higher in case of isolation of respiratory syncytial virus. There is no statistically significant differences between diagnostic parameters received for mariPOC and immune chromatographic tests at diagnosing influenza virus A and respiratory syncytial viral infection.

[Epitope analysis of the hemagglutinin molecule of the Victoria lineage influenza B viruses].

A panel of five monoclonal antibodies (MAbs) to the HA1 molecule of the influenza B virus of the Victorian lineage with high virus-neutralizing activity was developed. For identification of the virus neutralizing epitopes in HA1 escape mutants (EM) of the influenza BIShandong/07/97 and B/Malaysia/2506/04 virus were selected using virus- neutralizing antibodies (MAbs). Three EMs had single, two--double and one--triple amino acid substitutions (AAS) in HA1 (H122N, A202E, K203T, K2031, K203N or A317V). In addition, AAS N197S was detected in three EMs. A correlation of AAS identified with peculiarities of interaction of EMs with Mabs was discussed.

[Characterization of cold-adapted influenza strain A/HongKong/1/68/162/35 as a potential donor of attenuation and high reproduction].

Live and inactivated vaccines are currently produced using virus reassortants originating from various gene donors of internal proteins. Based on the pandemic virus A/Hong Kong/1/68 (H3N2), a cold-adapted thermo-sensitive strain A/Hong Kong/1/68/162/35 was generated. It is distinguished for its high reproductive capacity (9-9.5 lg EID50), and hemagglutinating activity (1:1024-1:2048). The strain has ts and ca phenotype: reproductive capacity at t = 39 degrees C is 1.0 lg EID50; at t = 26 degrees C, 8.5 lg EID50. A total of 16 mutations have emerged from comprehensive sequencing of the virus genome. Among them 10 mutations were located in the genes of polymerase complex and NP, with respective amino-acid substitutions. The stability of strain characteristics, such as attenuation to humans and high reproductive capacity, were confirmed by repeated sequencing of the genome after tenfold passing of the virus in chicken embryos. Reassortants of the strain A/Hong Kong/1/68/162/35 with the wild-type viruses have inherited useful features of donor virus.

[Development of influenza surveillance in Russia in the system of the WHO national influenza center].

Analysis of development influenza activity season 2010-2011 is presented. Significant participation of influenza A(H1N1)pdm09 virus and influenza B of Victoria lineage virus in the epidemic morbidity structure with minor participation ofA(H3N2) virus was revealed. The influenza viruses isolated in Russia according to antigenic properties were similar to the strains included in the vaccine composition. Drift variants of influenza A(H1N1)pdm09 viruses isolated in Astrakhan and St.-Petersburg were recognized using WHO CC in London as representatives of three new genetic groups.

[Genetic diversity and molecular evolution of the influenza A viruses in Russia during 2006-2012].

The results of molecular genetic analysis of more than 280 strains of influenza A virus subtypes H1N1 and H3N2 circulating in Russia in 2006-2012 are presented. The genetic changes underlying the evolution of the virus strains and sensitivity to antiviral drugs were analyzed. Significant changes in the genetic structure of influenza A viruses circulating in the Russian Federation and their phylogenetic affiliation are shown to occur within the studied period. The studies identifying codons under the positive selection in silico in the genes encoding surface proteins of the influenza virus were demonstrated to be efficient for the analysis of the antigenic drift and direction of evolutionary variability of the influenza viruses.

[Analysis of pandemic influenza in Russia as a part of the global process based on data of an influenza monitoring reference center].

AIM: Characterization of features of influenza pandemic development in Russia in relation to global process. MATERIALS AND METHODS: Pandemic monitoring was performed by using results of integrative analysis of laboratory diagnostic and population morbidity data from 49 supporting bases of Federal center of influenza from various cities in Russian Federation. Isolation of influenza virus was carried out in MDCK cells and chicken embryos under BSL-3 conditions. Reference virus A/California/07/09 obtained from CDC (Atlanta, USA) and antisera against this strain contained in WHO kit were used for antigenic analysis; rat antisera, new monoclonal antibodies against pandemic influenza virus developed by Research institute of influenza were also used. RESULTS: Based on PCR monitoring during epidemic peak, rate of pandemic influenza identification reached 45-49% of examined patients. About 53% of lethal cases of respiratory infections were caused by pandemic influenza virus, while predominately young people died from pneumonia and acute respiratory distress syndrome. Russian isolates generally were antigenically and genetically similar to the parent pandemic strain--influenza virusA/California/07/09, but contained S203T substitution in hemagglutinin. A number of strains contained D222G mutation that is responsible for the expansion of substrate specificity, as well as strain specific substitutions in hemagglutinin and neuraminidase molecules. The investigated isolates were resistant to remantadin, but sensitive to oseltamivir. CONCLUSION: Due to the formation of population immunity after the end of the first pandemic wave new drift variants of the virus capable of overcoming this formed immunity should be expected that apparently will require the correction of vaccine composition for the 2011 - 2012 season.

[The 2009 pandemic influenza in Russia. I. Diagnosis and molecular biological characteristics of the virus].

The analysis of 1558 clinical samples revealed influenza virus A(H1N1v) RNA in 339 patients with influenza and 163 fatal cases,which was made in May to December 2009. Data on the antigenic properties of more than 250 of pandemic virus strains isolated at the Research Institute of Influenza and the molecular genetic characteristics of 31 strains are presented. All the test isolates were found to have the S203 substitution in hemagglutinin, which was characteristic of one of 5 minor genome A(H1N1v) virus variants found in the United States and Mexico in 2009. All the test strains contain the S31N substitution in the M2 protein, which determines viral resistance to adamantine, and have no H275Y substitution in neuraminidase, which determines oseltamivir resistance. The substitution of amino acid residue of Asp to Gly at position 222 of HA was found in 8 (73%) of 11 isolates from postmortem lung and trachea samples and in 2 (10%) of 20 isolates from nasopharyngeal swabs. The determination of the pathogenic role of this substitution calls for further investigations.

[Pathogenic aspects of influenza during the epidemics caused by A/H1N1v virus in 2009-2010 according autopsy data].

The paper is based upon the results of clinic-pathological and virological correlations in 29 lethal cases of influenza in Saint-Petersburg and Leningrad region during the epidemics 2009/2010. Immunohistochemical analysis of lungs, heart and brain using monoclonal sera to HA and HP proteins of influenza virus, virological and morphological analysis of experimental influenza in mice infected by A/WSN/33 (HIN1) and A/California/07/09 (H1N1) viruses had been carried out. In the majority of investigated strains was proved the amino acid mutation with replacement D222G. The replication of virus was demonstrated at the late stages of diseases, but the desquamation of respiratory epithelium and cytoproliferative weren't found out. Besides the "influenza cells", previously described by A. V Zinserling the cells with enlarge light nuclei were observed. Patients with influenza died from respiratory distress syndrome with minimal bacterial infection. We've established that H1N1 virus not only damages the cells of respiratory epithelium and alveolar macrophages but it can injure endothelium of different organs and neuroglia. The questions which have to be discussed are listed.

[Molecular characteristic of influenza virus A H5N1 Strains isolated from poultry in Kurgan Region in 2005].

During the latter half of 2005 a widespread outbreak caused by influenza highly pathogenic H5N1 virus among wild and domestic birds occurred in Russia. As pathogenicity level is a polygenic feature and majority of individual genes of influenza A viruses contribute to pathogenicity of influenza viruses to birds, animals and humans. Nucleotide sequencing of the entire genome of influenza H5N1 virus isolates obtained in Kurgan region (Western Siberia) was performed. Structure of viral proteins was analyzed according to the predicted amino acid sequences. HA receptor-binding site of A/chicken/Kurgan/05/2005 and A/duck/Kurgan/08/2005 strains was typical for avian influenza viruses and contained Glu and Gly at positions 226 and 228, respectively. Structure of the cluster of positively charged amino acid residues at the cleavage site was identical for all isolates: QGERRRKKR. According to the data of neuraminidase structure analysis NA of the H5N1 isolates tested was suggested to belong to Z genotype. Amino acid residues typical for birds were revealed in 30 out of 32 positions of M1, M2, NP, PA and PB2 proteins determining host range specificity. One strain isolated in Kurgan contained lysine in position 627 of PB2 protein. Kurgan isolates was shown to have remantadine-sensitive genotype. Glutamic acid was found at position 92 of NS1 protein in both strains indicating virus resistance to interferon. Phylogenetic analyses allowed relating Kurgan isolates to subclade II of clade II of highly pathogenic H5N1 influenza viruses.

[Influence of cultivation conditions on bacterial DNA content and bacterial membrane permeability].

The study included measurement of intracellular and extracellular DNA content and evaluation of bacterial membrane condition during plankton growth and in isolated communities. This was performed at different stages of bacterial development and after heating at the temperature of heat shock system activation. The content of intracellular bacterial DNA in the community decreased after 72 hours of cultivation growth more prominently than during plankton growth. Change of intracellular bacterial DNA content in the community overtook the increase of membrane permeability, which may indicate the onset of apoptosis. Heating at 420' decreased the permeability of bacterial membranes in the community, but did not affect this parameter in the bacteria during plankton growth. Extracellular DNA was found in the matrix of the communities after 24 hours of growth. Appearance of this DNA after 48-74 hours of cultivation may be associated with apoptotic process.

[Usage of polymerase chain reaction in complex diagnosis of hepatitis B]. / Primenenie polimeraznoi tsepnoi reaktsii v kompleksnoi diagnostiki gepatita B.

Sera from 926 patients were analyzed by PCR using universal primers to surface gene of hepatitis B virus (HBV). HBV DNA was detected in 195 specimens. There were no serological markers of HBV in 8.2% of these sera, but later they were detected in patients' sera. In patients without HBV DNA in the serum, specific HBV antigens and antibodies were detected in 62%. Only in 14% of them the clinical picture of the disease corresponded to acute viral hepatitis, although the blood for PCR analysis was collected during the late stages of the infection. The rest cases were referred to mixed hepatitis C + D. Comparison of the results of PCR test and detection of serological virus replication markers HBeAg and HBeAb showed the presence of HBV DNA in 28% cases without HBeAg.