[Dynamics of the cell cycle in human endothelial cell culture infected with influenza virus].

Cell cycle in a culture of endothelial cells EAhy 926 infected with influenza virus was investigated. Cytometric analysis of culture, synchronized using contact inhibition, has shown that the exposure to the influenza virus in cells EAhy 926 lengthened S-phase of the cell cycle. This result has been tested and proven on culture EAhy 926 treated with nocodazole. Compared with lung carcinoma cells A549, in which influenza virus provokes the arrest of G0/G1 phase of the cycle, elongation of S-phase of cycle at a similar infection of endothelial culture EAhy 926 indicates that the influenza virus differently affects the dynamics of the cell cycle according to the origin of the infected culture.

Alterations in cell cycle dynamics in human endothelium cell culture infected with influenza virus.

The cell cycle of endothelium EAhy 926 cell culture infected with influenza virus has been studied. Cytometric analysis of cell culture synchronized by contact inhibition revealed the elongation of the S phase of the cell cycle in EAhy 926 cells under the influence of influenza virus. This result was shown in an EAhy 926 culture infected with influenza virus and treated with nocodazole. Comparison of a lung carcinoma A549 cell line in which influenza virus causes G0/G1 arrest and of an endothelial EAhy 926 cell line in which the same infection leads to S-phase elongation allows it to be suggested that different effects of influenza virus on cell cycle dynamics depend on the origin of infected cells.

[The influenza viruses and their surface proteins impact on the metabolism of human blood vessel endothelium cells].

The modern influenza virus subtypes H3N2, H5N1, and H1N1 reduced the metabolism of the endothelial cells within the range from 20% to 60% (compared with control). The degree of the activity of the dehydrogenase reduction depended on the dose of virus and time of virus reproduction. HA and NA also actively reduced the metabolism of the cells ranging from 5% to 60%, depending on the concentration of the proteins and time of their impact on cells. Neuraminidase was more active than hemagglutinin in the MTT test (at concentration 50 microg protein/ml).

[Ability of the influenza viruses and their envelope proteins to stimulates endothelial cells apoptosis in vitro].

The ability of the modern epidemic strains of influenza virus type A (subtypes H5N1, H3N2, H1N1pdm) and their surface proteins, hemagglutinin (HA) and neuraminidase to cause the activation of the cellular protein caspase-3 and stimulate the emergence of phosphatidylserine on the membrane of human endothelial cell line EAhy926 has been studied. It was questioned how the viruses and their surface proteins that were studied cause the activation of caspase-3 after 0.5 h of exposure that recorded immunogistotsitohimicheski. The test viruses and neuraminidase (concentration 10 µg/ml) led to the appearance of phosphatidylserine on the cell membrane in a time interval of 2-8 h from the beginning of the treatment, which was recorded by flow cytometry. The death of endothelial cells when exposed to the HA (in a concentration of 50 µg/ml) and in the same time frame was not accompanied by the appearance of phosphatidylserine. The specific feature of apoptotic cell death during the reproduction of the virus are described, as well as the effects of viral proteins.

[Influenza virus reproduction in the endothelial cells of human blood vessels].

The current epidemic strains of the influenza subtypes Y5N1, H3N2, and H1N1 can be reproduced in the cultured human endothelial EAhy926 cells with an infective activity of 3.0-4.5 Ig TCD50. These findings were confirmed by the analysis of the autopsy material from patients who had died from influenza during the 2009-2010 epidemic, which showed influenza virus HA and NP proteins in the pulmonary blood vascular endothelium. The results obtained reflect a new aspect of the pathogenesis of influenza, which is important for the design of antiviral agents and for the development of combination therapy.

[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.