Репозиторий Университета

© 2018 Chernokhaeva, Rogova, Kozlovskaya, Romanova, Osolodkin, Vorovitch and Karganova. Tick-borne encephalitis (TBE), caused by the TBE virus (TBEV), is a serious public health threat in northern Eurasia. Three subtypes of TBEV are distinguished. Inactivated vaccines are available for TBE prophylaxis, and their efficacy to prevent the disease has been demonstrated by years of implication. Nevertheless, rare TBE cases among the vaccinated have been registered. The present study aimed to evaluate the protective efficacy of 4 TBEV vaccines against naturally circulating TBEV variants. For the first time, the protection was evaluated against an extended number of phylogenetically distinct TBEV strains isolated in different years in different territories. The protective effect did not strongly depend on the infectious dose of the challenge virus or the scheme of vaccination. All vaccines induced neutralizing antibodies in protective titers against the TBEV strains used, although the vaccines varied in the spectra of induced antibodies and protective efficacy. The protective efficacy of the vaccines depended on the individual properties of the vaccine strain and the challenge virus, rather than on the subtypes. The neutralization efficiency appeared to be dependent not only on the presence of antibodies to particular epitopes and the amino acid composition of the virion surface but also on the intrinsic properties of the challenge virus E protein structure.

© 2018 Bulletin of Siberian Medicine. All rights reserved. The aim of the investigation was to determine the characteristics of the immune response regulation for pulmonary tuberculosis (TB) and to analyze the role of regulatory T cells in the immunopathogenesis of TB with eosinophilia in the blood, depending on the clinical form of the disease and sensitivity of Micobacterium tuberculosis to anti-TB drugs. Materials and methods. 157 patients who were initially diagnosed with infiltrative and disseminated TB were examined. The material of the study was venous blood and culture of mononuclear leukocytes isolated from venous blood. The content of interleukin (IL) 4, IL-10 and transforming factor beta (TGFβ) in culture suspensions of mononuclear leukocytes in vitro and IL-5 in the blood was determined by enzyme-linked immunosorbent assay (ELISA) test. The expression of surface molecules CD4, CD20, CD25 and intracellular transcription factor Foxp3 by lymphocytes of the blood was evaluated by flow cytometry. The obtained results were analyzed by statistical methods. Results. It is shown that excessive generation of regulatory T cells in patients with TB is associated with eosinophilia of the blood and imbalance of immune response regulation mechanisms. In TB with eosinophilia, an increase in the number of Foxp3-positive regulatory T cells in the blood is combined with in vitro hypersecretion of anti-inflammatory cytokines TGFβ, IL-10, IL-4 and an increase in the content of CD20+ B lymphocytes and IL-5 in the blood. These changes are most pronounced in the disseminated form of TB in combination with drug resistance. Conclusion. Characteristics of immunoregulation at TB with blood eosinophilia are associated with activation of immunosuppression mechanisms and polarization of immune response towards Th2-dependent pathway.

© 2017 Izdatel'stvo Meditsina. All rights reserved. The enzyme-linked immunosorbent assay (ELISA) and the neutralization test (NT) are often used to determine the level of seropositive population and to evaluate the immunogenicity of vaccines. ELISA provides information on the total pool of antiviral antibodies, while NT allows the antiviral protection level of a person to be estimated. It is assumed that the 1: 100 titer in ELISA and the 1: 10 titer in NT are protective. Obviously, the ratio of the total pool and virus neutralizing antibodies can vary as a result of natural immunization or vaccination. In this study, two methods were used to study the blood serum samples taken in a group of inhabitants of the Sverdlovsk region aged from 1 to 60 years. The samples were collected before immunization and 30 days after two immunizations with inactivated vaccines against tick-borne encephalitis of different manufacturers. Immunizations were performed either according to a standard scheme (30-day interval between immunizations), or according to an emergency scheme (14-day interval). It was shown that the data on the presence of antiviral antibodies in protective titers obtained by ELISA and NT were consistent in more than 85% of cases. The discrepancies between the data are due, in the first place, to the difference in the sensitivities of the two methods. The proportion of seropositive people according to NT data is always greater than that according to the results of ELISA. Nevertheless, among 174 children, about 5% of recipients after a double immunization were seropositive according to ELISA, but did not have neutralizing antibodies in protective titers.