Vol 4, No 1 (2014)

Abstract. T follicular helper cells (Tfh) are a CD4+ Th cell subset promoted the cognate control of antigen-specific B cell immunity. Upon first contact with antigen-primed B cells, Tfh can support either extrafollicularly differentiation into short-lived plasma cells (PC) or enter follicles to form germinal centers (GC). Signaling lymphocytic activation molecule (SLAM) interaction between Tfh and activated B-cells is essential for GC development. Within GC, Tfh regulates the fate of antigen-specific GC B cells expressing high-affinity B cell receptors to develop memory B cell (Bm) or long-lived PC. Short-lived PC produce low-affinity IgM and IgG3 early antibodies. Both Bm and long-lived PC have high-affinity class-switched IgA and IgG, predominantly IgG1 antibodies. Measles virus uses human SLAM-molecule as a cellular receptor. SLAM is expressed on dendritic cells and activated B and T-cells. This is an important regulator of the isotype switching and antibody affinity maturation, especially IgG3-IgG1 switching. Development of long-term humoral immunity, charac terized by the formation of high-affinity predominantly IgG1 antibodies, is a critical component of protective immunity to pathogens and the major goal of vaccination. However, the mechanisms involved in the shaping and sustaining of long-term humoral immunity remain poorly understood.

Abstract. Enteroviruses are widely distributed human infectious pathogens. In spite of infection a disease does not manifest in majority number of cases. However, in some infected persons the different kind of symptoms can be observed; from common cold signs up to  aseptic (serous) meningitis and myocarditis. Severe enteroviral cases with lethal outcomes are rarely reported. Ability of enteroviruses to cause large outbreaks and even epidemic distribution is very significant for health care systems. Taking in account a high genetic diversity of enteroviruses it is possible appearance of new highly pathogenic strains in the future. In some countries including the Russian Federation the permanent surveillance for enteroviral infections is provided besides of WHO polio elimination program. The laboratory diagnostics of enterovirus infections is complicated by numerous of pathogen serotypes. Thus, classical virological methods should be supported by molecular-biological tools to sequence pathogen genome and to define phylogenetic relations between different enterovirus strains.

Abstract. Tick-borne encephalitis (TBE) is severe neuroinfectious disease with involvement of immune mechanisms in pathogenesis. Comparative analysis of synthesis of key cytokines had been performed for the TBE virus (TBEV) infected cells and in the presence of inactivated vaccine against TBE in vitro. Persistent TBEV infection of immortal tissue culture of human larynx cancer cells caused transcription activation of interferons IFNα, IFNγ, IFNλ1, interleukins IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12, tumour necrosis factor TNFα as well as one of apoptosis factors Fas. Comparison of transcription and production of cytokines revealed that the TBEV infection resulted in posttranscription Th1 shift of cytokine response. In the presence of inactivated vaccine against TBE based on the same strain Sofjin of the TBEV activation of transcription of cytokines IFNα, IFNλ1, IL-4, IL-10 was also observed as after the TBEV infection that together with an additional stimulation of GM-CSF production might serve as an evidence of Th2 response. Involvement of IFNIII type (IFNλ1) both during persistent infection and after addition of inactivated vaccines was found in the first time. Differences in dynamics of cytokines IL-2, IL-8, IL-10, IL-12, TNFα response during the TBEV infection and in the presence of inactivated vaccine are described.

Abstract. A comparative analysis of the results of bacteriological study of blood samples obtained from 1608 patients with secondary immunodeficiency of different origins has been conducted. It was established that within the spectrum of pathogens of bacteremia in these onco-urological profile patients, enterobacteria was the predominant one. In post–liver transplantation patients micromycete was predominant, and for wounded patients and victims with serious injuries staphylococci were more often isolated.

Материалы научно-практической конференции молодых ученых и специалистов «От эпидемиологии к диагностике инфекционных заболеваний: подходы, традиции, инновации», 23–25 апреля 2014 года, Санкт-Петербург.