The immunodiagnosis of tick-borne encephalitis by using the indirect immune rosette formation reaction

200 patients suspected for tick-borne encephalitis (TBE) were examined by the method of the indirect immune rosette-formation test. In 70.15% of patients with the serologically confirmed diagnosis of TBE immune lymphocytes were detected as early as on day 1 of examination. The level of rosette formation was higher in the meningeal form of the disease. Rosette-forming lymphocytes were also detected in 24.06% of patients with the serologically unconfirmed diagnosis of TBE. The test is proposed for the early diagnosis of TBE.     

Correlation of TBE Incidence with Red Deer and Roe Deer Abundance in Slovenia

Tick-borne encephalitis (TBE) is a virus infection which sometimes causes human disease. The TBE virus is found in ticks and certain vertebrate tick hosts in restricted endemic localities termed TBE foci. The formation of natural foci is a combination of several factors: the vectors, a suitable and numerous enough number of hosts and in a habitat with suitable vegetation and climate. The present study investigated the influence of deer on the incidence of tick-borne encephalitis. We were able to obtain data from deer culls. Using this data, the abundance of deer was estimated and temporal and spatial analysis was performed. The abundance of deer has increased in the past decades, as well as the incidence of tick-borne encephalitis. Temporal analysis confirmed a correlation between red deer abundance and tick-borne encephalitis occurrence. Additionally, spatial analysis established, that in areas with high incidence of tick-borne encephalitis red deer density is higher, compared to areas with no or few human cases of tick-borne encephalitis. However, such correlation could not be confirmed between roe deer density and the incidence of tick-borne encephalitis. This is presumably due to roe deer density being above a certain threshold so that availability of tick reproduction hosts has no apparent effect on ticks'' host finding and consequently may not be possible to correlate with incidence of human TBE.     

Role of sialic acids in the immune response formation in tick-borne encephalitis

The content of individual forms of sialic acids and total sialic acids in the lymphocytes of tick-borne encephalitis patients has been studied. The level of sialic acids has been found to depend on the clinical form of the disease and on the content of specific IgM and IgG to tick-borne encephalitis virus. Similar dependence has been established with respect to total sialic acids in lymphocytes.     

Effectiveness of the seroprophylaxis of tick-borne encephalitis depending on the titer of homologous gamma-globulin antihemagglutinins

To give a rationale for using homologous gamma globulin with antihemagglutinin titers of 1 : 20 to 1 : 80 for the prophylaxis of tick-borne encephalitis, 5-year observations covering all persons attacked by ticks in one of the intensive natural foci of the disease in the Western Urals have been made. The threefold statistically significant difference in the morbidity rate of tick-borne encephalitis between groups of persons immunized and not immunized with gamma globulin has been shown.     

Reactogenicity and antigenic activity of a chromatographic cultured purified and concentrated inactivated dried vaccine against tick-borne encephalitis

The study of the characteristics of a new dried tissue-culture purified concentrated inactivated vaccine against tick-borne encephalitis, manufactured in the USSR, has revealed that the preparation is moderately reactogenic and produces no definite side effects in the vaccinees. In the process of the controlled epidemiological trial the optimum vaccination schedule for the primary immunization of adults against tick-borne encephalitis with the new preparation has been determined by the study of serum samples from the vaccinees in the hemagglutination inhibition test and the neutralization test in tissue culture. In accordance with this vaccination schedule the course of primary immunization with the chromatographic variant of the concentrated vaccine consists of two injections in a dose of 0.5 ml, made at an interval of 6 months.     

蜱传脑炎病毒非结构蛋白NS2B-NS3与NS5的研究进展

蜱传脑炎病毒是引起严重的中枢神经系统疾病蜱传脑炎的病原体,每年在欧洲、俄罗斯远东地区、日本和中国北部报道的蜱传脑炎病例数约为10000-12000例,且在我国和多个欧洲国家的发病率逐渐增高,正成为人类健康的潜在危害。主动免疫是预防蜱传脑炎的有效措施,包括我国在内的多个国家已研制出安全性较高的疫苗,但在我国流行省份的疫苗接种较为有限,特异性抗病毒药物的研发或许是治疗蜱传脑炎病毒感染的研究方向之一。蜱传脑炎病毒非结构蛋白NS2B-NS3与NS5因为在病毒基因组复制、加帽和宿主免疫调节中的重要作用,成为关键的抗病毒药物研发靶点。本文综述了蜱传脑炎病毒非结构蛋白NS2B-NS3与NS5的三维结构和抑制剂研发工作,为深入探究该病毒感染的分子机制和抗病毒药物研发提供参考。     

Use of protein A in the immunosorbent analysis of antibodies to the tick-borne encephalitis virus

The results of the studies made with a view to developing the method for the determination of specific antibodies to the antigen of tick-borne encephalitis virus in human blood serum and liquor are presented. The method is based on the capacity of Staphylococcus aureus protein A to bind with Fc-region of immunoglobulins, which makes it possible to use this protein as the "second" system of antibodies. The conditions for the sorption of the antigen on polystyrene test tubes and for binding 125I-or horse radish peroxidase-labeled protein A preparations with antibodies have been determined, and the method has been approved in tests made on sera and liquor obtained from donors and tick-borne encephalitis patients.     

Characteristics of the relation of tick-borne encephalitis morbidity to natural factors

Data and tendencies characteristic of relationship between the severity of the course of tick-borne encephalitis and a number of biotic and climatic factors have been revealed by the method of information analysis. On the basis of relationships established in this study the authors make a suggestion concerning two most important stages in the formation and manifestation of the clinical features of tick-borne encephalitis in different areas of endemic territories, linked, on one hand, with the population selection of the infective agent and, on the other hand, with temperature conditions and the duration of the cold season.     

Synthetic fragments of the NS1 protein of the tick-borne encephalitis virus exhibiting a protective effect

Potentially immunoactive regions of the NS1 nonstructural protein of the tick-borne encephalitis virus that can stimulate the antibody formation in vivo and protect animals from this disease were chosen on the basis of theoretical calculations. Eleven 16- to 27-aa peptides containing the chosen regions were synthesized. The ability of the free peptides (without any high-molecular-mass carrier) to stimulate the production of antipeptide antibodies in mice of three lines and ensure the formation of protective immunity was studied. Most of these peptides were shown to exhibit the immunogenic activity in a free state. Five fragments that can protect mice from the infection by a lethal dose of tick-borne encephalitis virus were found.     

Synthetic fragments of the NS1 protein of the tick-borne encephalitis virus exhibiting a protective effect

Potentially immunoactive regions of the NS1 nonstructural protein of the tick-borne encephalitis virus that can stimulate the antibody formation in vivo and protect animals from this disease were chosen on the basis of theoretical calculations. Eleven 16-to 27-aa peptides containing the chosen regions were synthesized. The ability of the free peptides (without any high-molecular-mass carrier) to stimulate the production of antipeptide antibodies in mice of three lines and ensure the formation of protective immunity was studied. Most of these peptides were shown to exhibit the immunogenic activity in a free state. Five fragments that can protect mice from the infection by a lethal dose of tick-borne encephalitis virus were found.     

The possible role of alpha 2-macroglobulin in regulating the immune components of the brain in tick-borne encephalitis

In tick-borne encephalitis certain immunopathological reactions develop in the tissues of the central nervous system; alpha 2-macroglobulin may serve as the marker of the activity of these reactions. The dynamic study of liquor taken from 16 patients with the meningeal and focal forms of tick-borne encephalitis (TBE), 8 patients with severe craniocerebral traumas accompanied by meningitis and 10 patients with osteochondrosis was made. As revealed in this study, in TBE patients the level of alpha 2-macroglobulin increases 3.5-fold and remains stable during the acute period of the disease.     

Combined focus of tick-borne encephalitis, tick-borne rickettsiosis and tularemia in the habitat of Haemaphysalis concinna in south central Siberia

For the first time in the Krasnoyarsk region the population Haemaphysalis concinna ticks were found to be infected with the causative agents of three natural focal tick-borne infections--tick-borne encephalitis, tick-borne rickettsiosis and tularemia. The existence of the combined natural focus of these three infections has been confirmed by epidemiological data. Ticks Dermacentor nuttalli also play a similar role in combined foci of tick-borne encephalitis and tick-borne rickettsiosis in these focal territories.     

The relationship of the antigenic characteristics of the tick-borne encephalitis virus to the level of the protective activity of inactivated cultured vaccines]

As shown in this study, the immunization of animals with killed vaccines against tick-borne encephalitis (TBE) leads to the formation of specific immunity, depending on the antigenic structure of the vaccine strain and the test strains used for challenge. Vaccines obtained on the basis of the TBE virus strain of the Eastern antigenic variant induced the development of a wider spectrum of specific protective activity than vaccines obtained on the basis of the TBE virus strain of the Western antigenic variant.     

The clinico-epidemiological characteristics of Powassan encephalitis in the southern Soviet Far East]

The present communication deals with the analysis of 14 cases of Powassan encephalitis. As shown in this study, the course of this infection may be accompanied by symptoms indicating the presence of cerebral and meningeal lesions (in 7 cases meningoencephalitic forms with one fatal outcome and in 2 cases meningeal forms were registered) or take febrile and inapparent forms (5 cases). Powassan encephalitis was found to give characteristic symptoms of cerebellovestibular lesions, differentiating this disease from tick-borne encephalitis (TBE). The cases of mixed infections caused by TBE virus, Powassan encephalitis virus and tick-born Borrelia were found to be possible.     

A cultured concentrated inactivated vaccine against tick-borne encephalitis studied during the immunization of children and adolescents

The word deals with the results obtained in the study of the reactogenicity and immunological activity of concentrated and inactivated tissue-culture tick-borne encephalitis vaccine, manufactured by the Chumakov Institute of Poliomyelitis and Viral Encephalitides, in the immunization of children and adolescents. The vaccine proved to be moderately reactogenic and exhibited pronounced immunological activity. In 91.5% of the immunized children the fourfold increase of the antibody level was observed. On the basis of the data obtained in this study the tick-borne encephalitis vaccine was recommended for use in medical practice for the prophylaxis of tick-borne encephalitis among children and adolescents.     

The immune status of patients with tick-borne encephalitis studied by using an immune reagent kit for the determination of human lymphocyte subpopulations

The comparative study of disturbances in the immune status of patients with different clinical forms of tick-borne encephalitis has revealed that in the severe (meningeal) form of the disease more pronounced imbalance in the immune system develops, especially with respect to immunoregulatory subpopulations of T-lymphocytes. This seems to be the cause of delayed activation of immune processes in this group of patients in comparison to those having an aborted course of the disease.     

The infectiousness of Ixodes persulcatus ticks with the causative agents of Lyme disease and tick-borne encephalitis simultaneously

By means of individual bacteriological and virological investigations of adult Ixodes persulcatus ticks and comparison of obtained results there has been established their simultaneous spontaneous infection with agents of Lyme disease and tick-borne encephalitis. A possible frequency of such mixed infection in these vectors is being discussed.     

Use of western blotting methods in diagnosis of viral infection causing tick-borne encephalitis]

A Western blot method for investigation of antigens and of immunological response to tick-borne encephalitis was prepared. An analysis was performed testing cross reactions of proteins of prepared antigen with sera for four Polish strains of tick-borne encephalitis and four other flaviviruses. Usefulness for diagnosis of infections in humans was determined by comparison of Western blot method with ELISA immunoenzymatic test. It was found that elaborated method permits equally as ELISA for evaluation of immune response in immunoglobulin classes. By evaluation of response for individual virus components, Western blot method enables at the same time verifications of nonspecific determinations which result from reaction of antibodies present in tested diagnostic materials with nonviral antigens.     

Nonstructural protein 1 of tick-borne encephalitis virus activates the expression of immunoproteasome subunits

The interaction of viral proteins with host cell components plays an important role in antiviral immune response. One of the key steps of antiviral defense is the formation of immunoproteasomes. The effect of nonstructural protein 1 (NS1) of tick-borne encephalitis virus on the immunoproteasome formation was studied. It was shown that cell expression of NS1 does not reduce the efficacy of the immunoproteasome generation in response to interferon-γ stimulation and even increases the content of the immunoproteasome subunits without the interferon-γ treatment. Thus, NS1 of tick-borne encephalitis virus activates, rather than blocks the mechanisms of immune defense in the cell.