Increasing the immunogenic and protective activity of the vaccine strain Yersinia pestis EV line NIIEG using synthetic immunomodulators

Introduction. One of the main tasks of specific plague prevention remains the development of vaccines and their application schemes aimed at improving the effectiveness of vaccination through the use of adjuvants and immunomodulators. The purpose of the study were comparative evaluation of the effect of drugs from the group of synthetic immunomodulators on the immunogenic and protective properties of the Yersinia pestis EV line NIIEG vaccine strain in model animal experiments. Materials and methods. White mice and guinea pigs were immunized with the vaccine strain Y. pestis EV line NIIEG. The animals of the experimental groups were injected with oligopeptides O1 (Threonyl-glutamyl-lysyl-lysyl-arginyl-arginyl-glutamyl-threonyl-valyl-glutamyl-arginyl-glutamyl-lysyl-glutamate), O2 (Glutamyl-cysteinyl-glycine disodium) and O3 (Arginyl-alpha-aspartyl-lysyl-valyl-tyrosyl-arginine) one hour before vaccination or three times before infection. On days 3, 14 and 21, antibody and cytokine products were studied. Animals were infected with the test strain Y. pestis 231(708) at a dose of 400 LD50. Results. It was found that a single administration of immunomodulators 1 hour before vaccination did not change the susceptibility of animals to the plague microbe: ImD50 = 5860 (O1); 5860 (O2); 6454 (O3) and 6876 (control) CFU for white mice and 446 (O1), 551 (O2), 446 (O3) and 578 (control) CFU for guinea pigs. Three-time administration of drugs to vaccinated animals led to a decrease in the ImD50 Y. pestis EV line NIIEG indicators in the group with O1 by 2.2 times (mice) and 1.8 times (guinea pigs), with O2 and O3 by 1.2 times, regardless of the biomodel compared with the control. The stimulating effect of O1 and O3 on the production of antibodies to F1 of the plague microbe and cytokines interferon-gamma, interleukin-10 has been established. Conclusion. The stimulating potential of synthetic immunomodulators on the immune system of biomodels immunized by Y. pestis EV line NIIEG has been demonstrated, which determines the prospects of research to improve the schemes of prophylactic vaccination against plague

Nucleolar Apparatus of Lymphocytes as an Indicator of Lymphoid Organs’ Functional Activity in the Context of Pre-Clinical Vaccine Evaluation

Studied has been the state of the nucleolar apparatus in lymphocytes of periphery lymphoid organs in laboratory animals vaccinated against plague and tularemia in order to evaluate predictive capability of the parameter in the context of pre-clinical evaluation of the vaccines under development, against particularly dangerous infections. For the detection of silver adjoining proteins, contained in the nucleolar organizer region (AgNOR), W.M.Howell and D.A.Black staining of semi-thin paraffin sections of lymphoid organs of the immunized BALB/c mice has been performed. For this purpose, ready-assembled panel, manufactured at BioVirtum, has been deployed. Under assessment of the functional state of immunogenesis organs in vaccinated against plague and tularemia animals revealed has been the increase in numbers of cells with three and more AgNOR-positive nucleoli in the nucleus of the lymphocytes of periphery organs of the biomodels’ immune system. It indirectly manifests proliferative capacity of immune system cellular component. Informativity of the quantitative evaluation of the cell proliferative activity by the reference to the status changes of AgNOR in the nuclei of immunogenesis organs’ lymphocytes makes it possible to entertain the possibility of introducing this method into the existing morphological vaccine quality assessment scheme at the stage of the pre-clinical trials

Interaction between Bacillus anthracis and Pattern-Recognizing Receptors of Innate and Adaptive Immunity

According to modern views, protection of an organism from different pathogens is achieved through functioning of the two chains of immune system - innate and acquired ones. Initially, receptors of non-specific immunity, including Toll-like receptors, identify conservative pathogen-associated molecular structures. The subsequent activation of signaling pathways leads to rapid neutralization and elimination of foreign agent. Concurrently, initiation of the adaptive immunity, and realization of pro-inflammatory reactions' cascade take place. The review summarizes literature data concerning peculiarities of innate and adaptive types of immunity in case of interaction between macro-organism and Bacillus anthracis. Protective antigen, lipoprotein, cell wall components, anthrolysine O, CpG DNA sequence and others are the potential ligands of Toll-like receptors in B. anthracis. Demonstrated are the results of experiments that bear evidence of the fact, that synthetic agonists of Toll-like receptors influence realization of B. anthracis cytotoxicity and course of infection in laboratory animals. Modificators of Toll-like receptor functions can be used as immunostimulators for designing of effective means of anti-infectious protection. Innate and adaptive components of the immunity, having their own unique mechanisms of the specific B. anthracis identification, interact with each other, strengthen and complement each other

Historical and Modern Views on the Problem of Specific Plague Prophylaxis

Objective of this review is to analyze diachronically paradigm shift as regards problems of specific plague prophylaxis and appreciate contribution of the present-day scientific discoveries in the sphere of plague agent investigations and peculiarities of its interaction with host organism to the solution of topical issues of vaccine development that will be safe and tangibly effective against this particularly dangerous disease. Outlined is the historical background of the conceptual evolution concerning specific plague prophylaxis and events that are landmarked with eminent scientific discoveries by A.Yersin, French researcher and microbiologist. Given are the data on the current state of plague immune-prophylaxis both in Russia and around the world. Through the prism of the latest researches that assume application of advanced technological resource of medical sciences (molecular biology, biotechnology, bioinformatics, molecular immunology) put forward is the prospective of search and construction of safe and effective anti-plague next generation vaccines

EFFECT OF IMMUNOMODULATORS AND ANTI-TULAREMIA VACCINATION ON APOPTOSIS AND LYSIS OF SPLENOCYTES INTERACTING WITH TULYARIN IN VITRO

Objective of the study is to evaluate the effect of immunomodulators on the intensity of the post-apoptotic lysis of sensitized organism leukocytes in the presence of specific antigens of tularemia microbe in vitro.Materials and methods. Flow cytometry method was used to determine the relative content of apoptotic and proliferating splenocytes obtained from mice, immunized against tularemia against the background of immunomodulation.Results and conclusions. Obtained is the evidence that is consistent with modern data on the massive leukocyte apoptosis and post-apoptotic leukocyte autolysis (secondary necrosis) in case of tularemia infection. Given the important role of secondary necrosis in the systemic inflammatory response development, the use of immunomodulators suppressing macrophage apoptosis and dead leukocyte lysis, emerging in the course of interaction with Francisella tularensis antigens, may be promising in order to reduce the live tularemia vaccine reactogenicity

Changes in Biomodels in Response to Recombinant Protective Anthrax Antigen Inoculation

one. The data obtained has substantiated the lack of an expressed damaging effect of the recombinant protective antigen on the cells and tissues of the macro­organism, as well as possibility of its application as one of the core components of the chemical anthrax vaccine

ПРИМЕНЕНИЕ МИКОГЕЛЬМИНТА Aphelenchoides saprophillus ДЛЯ УМЕНЬШЕНИЯ СТЕПЕНИ ПОРАЖЕНИЯ РОЗОВОЙ СНЕЖ-НОЙ ПЛЕСЕНЬЮ (Microdochium (Fusarium) nivale (Fr.) Samuels & I.C. Hallet) ОЗИМОЙ ПШЕНИЦЫ

Pink snow mold of winter wheat is caused by the fungus Microdochium (Fu- sarium) nivale. This disease is widely spread within Russian Federation on grain varieties; its injuriousness is expressed in planting destruction and rather often in total crop failure. In our laboratory experiments the mycohelminth Aphelenchoides saprophillus Franklin was put in number of ±100-200 examples per test tube (20 × 200 mm) on mycelium of fungus M. nivale at temperature 5, 15 and 27 °C. The temperature 5 °C was more favorable for cultivation of mycohelminth A. sapro- phillus on mycelium of fungus M. nivale. At this temperature the reproduction ra- tio of A. saprophillus was 6,5, while mycohelminth was used by whole foods avail- able (mycelia of fungus гриба M. nivale ) within 50-75 days. However at tempera- ture 15 °C the speed of reproduction of A. saprophillus slowed down (reproduction ratio 5,7) that naturally affected the population size. At the end of experiment sin- gle dead species were found in test tubes stored at temperature 15 °C, that cannot be observed in test tubes stored at temperature 5 °C. At the same time reproduction of A. saprophillus was not registered at temperature 27 °C. Methods of cultivation of A. saprophillus allows to create suspension of nematodes containing a large number of species. Applying in autumn water suspension made on the base of A. saprophillus on winter wheat allows to decrease the degree of spread of disease in spring from 65 up to 20,4 % which improves the productivity index of wheat and affect crop improvementРазработан метод выделения, культивирования и применения культуры нематод Aphelenchoides sapro- phillus для биологической борьбы с возбудителем ро- зовой снежной плесени озимой пшеницы. Выделение нематод A. saprophillus из растений и почвы проводили методом Бермана. A. saprophillus лучше размножаются на мицелии гриба Alternaria tenius. A. tenius культиви- ровали на картофельно-глюкозном агаре в термостате при t 26-27 оС в течение 5-10 сут. Нематод вносили по 100 особей в пробирку с культурой грибов, где в тече- ние 30-40 сут их число увеличивалось в 100 раз. Нема- тод от культуральной среды очищали методами смыва и Бермана. Суспензию нематод разводили водой и применяли из расчета 1 л на 1 м2 обрабатываемой площади с помощью садового опрыскивателя в пер- вой декаде октября. Аналогично культивировали не- матод A. saprophillus на культуре гриба Microdochium nivale. Внесение нематод A. saprophillus в дозе 160000 тыс. экз./м2 посевов озимой пшеницы позволяет сни- зить степень болезни весной в 3 раза, что способствует повышению урожайности на 14,4

Influence of the Protective Antigen, Produced by <i>Bacillus anthracis</i> Asporogenic Recombinant Strain, on the Immune System of Laboratory Animals

Assessment of immunogenicity and biological safety of protective antigen preparation obtained from asporogenic recombinant producer, B. anthracis 55ΔTPA-1(Spo-), is made on the mice (BALB/c species) and Guiney pigs models. It is shown that the development of adaptive immunity in the inoculated with purified protein laboratory animals is characterized by high titers of specific antibodies. Double immunization of biological models with antigen preparation confers protection from B. anthracis infection, commensurable with protective capacity of the live anthrax vaccine. Obtained are the data confirming the possibility to reduce the injected doze of the vaccine strain in case of subsequent single immunization with protective antigen. It is determined that recombinant protective antigen shows no sign of reactogenicity and does not damage thymocytes and splenocytes in laboratory animals when administered for immunization

Evaluation of Immunobiological Properties of Cholera Vibrio O1 and O139 Antigens

Evaluated are immunobiological properties of experimental preparation on the basis of Vibrio cholerae O-antigen, O1 and O139 serogroups on the mouse model: determination of toxicity, analysis of morphological changes in organs, and flow-cytometric monitoring of cell cycle of leukocytes, splenocytes and bone marrow cells. It is demonstrated that O-antigen 100 µg dose per mouse does not initiate either significant changes in parenchymatous organs, or imbalance of apoptosis and proliferation of immune-competent cells. Comprehensive assessment of immunobiological properties of the preparations allows to get an insight about their effect on macroorganism, possibility for further studies and their application as chemical vaccine components

IDENTIFICATION OF HLA II CLASS GENE ASSOCIATIONS OF THE MAIN HISTOCOMPATIBILITY COMPLEX WITH PECULIARITIES OF IMMUNE RESPONSE IN PERSONS VACCINATED WITH LIVE PLAGUE VACCINE IN THE REPUBLIC OF KALMYKIA

Objective of the study was to determine allelic variants of HLA II class haplotypes in persons living in the Republic of Kalmykia in the territory of Pre-Caspian sandy natural focus of the plague, immunized for epidemic reasons with live plague vaccine and search for associations of HLA class II haplotypes with peculiarities of post-vaccinal immunity development.Materials and methods. 20 individuals took part in the study. HLA typing was performed applying multiplex PCR. Production of immune-regulatory cytokines and antibody titers to fraction 1 of the plague microbe was determined using enzyme immunoassay. Statistical processing of the results was carried out using standard programs.Results and conclusions. Allelic variants of haplotypes HLA-DQA1, HLA-DQB1 and HLA-DRB1 class II of the main histocompatibility complex of 20 persons residing in Lagansky and Chernozemelsky districts of the Republic of Kalmykia have been identified. Determined have been the differences in the ratio of allelic variants of HLA-DQA1 and cytokine production INF-γ, TNF-α, IL-4 and IL-10 by the areas of residence. Association of the HLA-DRB1*01 allele with a high level of spontaneous and induced IL-10 cytokine production has been revealed at various times after booster vaccination. Further study of genes that regulate the development of immunity, along with immunological methods will make it possible to personalize the use of the existing vaccine against plague, and predict the immunogenicity and effectiveness of preventive drugs under development