The results of study relationship between antigen reactivity of T-lymphocyte population under
ex vivo
conditions and the intensity of protective post-vaccination immunity to causative agent of ...brucellosis are presented. Тaking into account the peculiarities of immunopathogenesis brucellosis and prevailing role of adaptive T-cell immunity to protect against the causative agent of infection, possibility predictive evaluation of protective immunity against brucellosis using CAST-tests is considered as the most important aspect of brucellosis problems. There is an obvious need for an ex vivo correlation analysis of the activity of antigen stimulation of T cells and the intensity of protective immunity formed after vaccination. A close direct proportional relationship was established between the number of live microbial cells
Brucella abortus
19BA vaccine strain administered and increase in
ex vivo
CD3-cell activation. A close correlation was revealed between
ex vivo
value of antigen-induced stimulation CD3-lymphocytes and level of post-vaccination immunological protection against brucellosis infection. It has been shown that in biomodels vaccinated against brucellosis with a T-lymphocyte stimulation coefficient of 50% or more (according to intensity of antigen-induced
ex vivo
expression CD25), 100% protection from the development of brucellosis infection after infection with
Brucella melitensis
at a dose of 1 × 10
3
live microbial cells are provided. At the same time, there was a lack of a close correlation between an increase in the dose of brucella vaccine strain administered to biomodels and a change in geometric mean antibody titer, presence of a weakly pronounced relationship between level of agglutinins and immunological protection of biomodels from development brucellosis infection and indicators bacterial contamination body.Based on results of study, it was demonstrated that it is possible to quantify the formation and protective activity of T-cell immunity to causative agent of brucellosis based on analysis of level antigen reactivity of CD3-lymphocytes
ex vivo
. The data obtained and described methodological approach can be used as a predictive criterion in assessing protective level of cellular immunity to causative agent of brucellosis in vaccinated or recovering patients, as well as in order to analyze effectiveness of specific prophylaxis brucellosis and study immunogenicity and protective properties candidate for brucellosis vWe present the results of studies related to antigen reactivity of T lymphocyte population under ex vivo conditions and the intensity of protective post-vaccination immunity to causative agent of brucellosis. Due to peculiarities of immunopathogenesis in brucellosis infection and prevailing role of adaptive T cell immunity for protection against the causative agent of infection, a predictive evaluation of protective immunity against brucellosis using CAST-tests is considered the most important issue in the field. There is an obvious need for ex vivo analysis of correlations between the activity of antigen stimulation of T cells, and the intensity of protective immunity raised after vaccination. A close direct relationship was established between the number of live microbial cells of
Brucella abortus
19BA vaccine strain administered, and increase in ex vivo CD3 cell activation. A close correlation (r = -0.841 ÷ -0.966,
R2
= 0.708 ÷ 0.969) was revealed between ex vivo values of antigeninduced stimulation of CD3 lymphocytes, and the levels of post-vaccination immunological protection against brucellosis infection. We have shown that, in biomodels vaccinated against brucellosis with a T lymphocyte stimulation coefficient of 50% or more (according to intensity of antigen-induced ex vivo CD25 expression), 100% protection against brucellosis infection was achieved after contamination with B
rucella melitensis
at a dose of 1×10
3
live microbial cells. At the same time, a lack of a close correlation was noted between an increased dose of Brucella vaccine strain administered to biomodels, and a change in geometric mean of antibody titer (
R2
= 0.357÷0.404), along with a weak relationship between the levels of agglutinins and immunological protection of biomodels from developing brucellosis infection and indices of
in vivo
bacterial contamination.These results suggest an opportunity to quantify development and protective activity of T cell immunity to the causal agent of brucellosis based ex vivo levels of antigen reactivity of CD3 lymphocytes. A correlation analysis between the state of T cell antigen reactivity and immunological resistance to brucellosis infection indicated a high degree of closeness between these indices. The key influence on activity of protective immunity is exerted by the levels of antigen reactivity of T lymphocytes, whereas the quotient of antigenic stimulation in CD3+CD25+ population may be considered the most informative index of immune protective activity. The data obtained and the described methodology may be used as a predictive criterion in assessing protective level of cellular immunity to causative agent of brucellosis in vaccinated or recovering patients, testing the efficiency of specific prophylaxis in brucellosis and studying immunogenicity and protective properties of candidate vaccines against brucellosis.
The aim of the work was to conduct a comparative phylogenetic analysis based on wgSNP of complete genomes of Brucella melitensis strains circulating in the territory of the Russian Federation. ...Materials and methods . wgSNP typing of 412 B. melitensis strains of the main genetic lineages of brucella from different regions of the world, including 64 strains isolated in the regions of the European and Asian parts of the Russian Federation, was performed. DNA sequencing was conducted on the “Ion GeneStudio S5 Plus” platform (“Life Technologies”, USA) using the “Ion Plus Fragment Library Kit library preparation” (“Life Technologies”, USA), according to the “Ion 520™ & Ion 530™ Kit – Chef” protocol (Revision D.0). Results and discussion . It has been established that the strains circulating in Russia belong mainly to genotype II, which has a wide geographical distribution across the territory of Eurasia. At the same time, subgenotype IIh prevails in the regions of Siberia, and Iii – in the European territory of the country. For the first time, sets of specific SNPs have been identified that allow for intraspecific differentiation of B. melitensis strains. The obtained results made it possible to determine the probable routes of introduction of the causative agent of brucellosis into the territory of the Russian Federation from China and the countries of the Middle East. The prospect of using an optimized wgSNP typing scheme to solve urgent problems in the field of molecular epidemiology of brucellosis is demonstrated. It includes determining the genotype and subgenotype of the pathogen associated with the probable geographical region of origin of infection, and identifying the genetic relations between strains with high accuracy.
The article discusses the technology of repair by welding the ring-welded joints of gas pipelines made of steel with high rates of deformability. The influence of technology on the structure and ...properties of welded joints has been studied. Choice of welding procedure for repairs of circular welded joints of gas pipelines is justified.
Introduction. To improve the epidemiological surveillance of brucellosis in Russia, a detailed analysis of incidence and characteristics of Brucella melitensis strains circulating in the territories ...of the country where there is a persistent epizootic and epidemiological problem with brucellosis is required.Purpose of the study. To study current trends in the brucellosis epidemic process and perform molecular analysis of Brucella isolates from the territories of Southern and North Caucasian Federal Districts with long lasting unfavorable situation with brucellosis — the Republics of Dagestan (RD), Kalmykia (RK) and Stavropol Krai (SK).Materials and methods. The analysis of the brucellosis incidence in the North Caucasus Federal District and the Southern Federal District was carried out on the basis of data from the Rospotrebnadzor Departments for the period 2011–2020. Total 56 cultures of Brucella melitensis, isolated in 1999–2019 from patients with brucellosis that permanently resided in RD, RK and SK were studied.Results. The key factor contributing to the epidemic manifestations of brucellosis in the south of the European part of Russia is the persistence of epizootic foci in cattle and small ruminants. The leading concomitant factors are as follows: the presence in the region of "hidden" epizootic foci, uncontrolled production of food products of animal husbandry and its illegal sale to customers, unauthorized movement of animals and livestock products, untimely delivery (concealment) of sick cattle for stamping out. Results of molecular analysis of B. melitensis strains indicate the circulation of a mixed population of brucella, which is generally characteristic of the entire region, without a pronounced confinement of isolates to separate administrative territories. At the same time, the entire studied sample of strains can be divided into two groups (72% and 28% of strains) based on MLVA-16 genotypes by the variability in the Bruce 19 locus, which makes it possible to associate a part of the studied strains with the territory of their isolation.Discussion. The data obtained make it possible to scientifically substantiate the possibility of considering the affected territories of the Southern Federal District and the North Caucasian Federal District as a single common persistent active anthropurgic epizootic focus with circulation of a mixed, but typical for the region population of Brucella strains.
An analysis of brucellosis incidence in Russia in 2013–2022 and the data on genetic diversity of
Brucella melitensis
and
Brucella abortus
populations isolated in Russia in 1939–2022 are provided in ...the review. Over the past decade, the epidemiological situation in Russia has been characterized as unstable against the background of persistent unfavorable conditions for brucellosis in cattle and small ruminants. During the period of 2013–2022 (9 months), 4298 epizootic foci as regards brucellosis in cattle (89164 sick animals) and 371 as regards brucellosis in small ruminants (13569) were registered. The largest number of epizootic brucellosis foci was recorded in the North-Caucasian and Southern Federal Districts. In 2013–2022, on average, 327 cases of brucellosis among people were registered annually, the incidence rate per 100 000 of the population was 0.24. Up to 70–90 % of brucellosis cases were detected in the south of the European part of the country. A trend towards deterioration of the situation on brucellosis in Volga (Penza and Samara Regions) and Central (Smolensk, Voronezh and Tula Regions) Federal Districts is observed. There is a connection between the intensity of epidemic manifestations of brucellosis and the level of anthropurgic enzooty of territories. In 2022, 467 cases of brucellosis were reported (0.32 per 100 000 of the population), which is 42.8 % higher than annual average values over 10 years. In 2023, a measure of stability of incidence rates, by 20–25 % above average long-term values, is to be expected. Incidence of brucellosis in humans will be within the range of 380–410 cases (0.26–0.28 per 100 000 of the population). The results of genotyping of
B. melitensis
strains point to an increase in the proportion of isolates with an MLVA-profile characteristic of strains from enzootic as regards brucellosis countries of Middle East and North Africa over past 20–25 years, which can indicate importation (introduction) of the infection from these territories to Russia through small ruminants and/or biomaterial from them.
An analysis of trends in the development of situation on brucellosis in the world over past decade and the data on the main risk factors for the occurrence of epidemiological complications regarding ...this infection in various regions of the world are provided in the paper. An expert assessment of the current epizootiological and epidemiological situation on brucellosis, the coverage of population and animals with immunization in the Russian Federation is given. Over 9 months of 2021, 210 potentially hazardous as regards brucellosis in cattle areas and 24 sites – as regards brucellosis in small ruminants – were registered in Russia. Compared to the same period in 2020, there was a decrease in the number of newly identified hazardous sites for bovine brucellosis by 35.8 % (117 areas). However, long-term upward trend in epizootiological adversity for bovine brucellosis in Russia persists. The epidemiological situation on brucellosis in the country for the period of 2012–2021 is characterized as unfavorable. Decrease in the number of newly detected human brucellosis cases (by 25.1 % of long-term average values) is observed against the background of persistent unfavorable epizootic conditions for brucellosis among epidemiologically significant species of small ruminants and cattle in regions with developed animal husbandry. In 2021, clusters of human cases were registered in the Republic of Dagestan and Penza Region. In the Republic of Dagestan, against the background of aggravation of epizootiological and epidemiological situation on brucellosis, there was also an alarming trend towards prevalence of a relatively high incidence among minors. The proportion of cases of brucellosis among children under the age of 17 in the Republic amounted to 60.3 % of the total number of minors with newly diagnosed brucellosis in Russia over the past 10 years. Taking into account current epizootic, epidemic situations and the long-term dynamics of the development of situation on brucellosis in the Russian Federation, the incidence of brucellosis among the population is predicted to be 10–15 % lower than the average long-term values – 0.18–0.20 per 100000 of the population – in 2022. The number of human cases of brucellosis can range from 250 to 300.
The aim
was to carry out a comparative analysis of the immunogenic activity of the live plague vaccine obtained on various nutrient media.
Materials and methods
. The subject of the study was the ...blood of outbred white mice immunized with a series of live plague vaccine based on Yersinia pestis EV NIIEG strain, produced using experimental and regulated nutrient media. The immunogenic activity of vaccines was studied through flow cytometry. The intensity of antigen-reactivity of lymphocytes was determined in cell tests in vitro, analyzing the early activation marker CD25+ . For the specific activation of lymphocytes, a complex of water-soluble antigens of the plague microbe was used. To identify the interdependence between the presence of protective anti-plague immunity and the level of CD 25+ expression intensity, the ED50 of the series under study was determined by the standard method.
Results and discussion
. A comparative analysis of the immunogenic activity of the live plague vaccine obtained on the experimental nutrient medium with the vaccine produced on Hottinger’s agar has been performed. When animals were immunized with doses of 4·103 , 2·104 and 1·105 live microbial cells (regulated doses), the highest level of expression of CD25 marker by lymphocytes was on the day 14, with a subsequent decrease on the day 21 after vaccination. When determining immunogenicity using the conventional method, a high degree of direct correlation between the number of surviving animals and an increase in the level of lymphocytes expressing markers of early activation has been established. Comparison has revealed the general pattern: when the lowest immunizing dose (8·102 ) was administered, activation of early immunity markers was not observed. In case of immunization with higher doses on days 7, 14 and 21, a proportional increase in the number of CD25-positive lymphocytes after stimulation with a specific antigen under in vitro conditions is detected in the blood of biomodels.
Background
. Triple negative breast cancer has no specific treatment sites for chemotherapy and is unfavorable in terms of prognosis. One of the drugs widely used in this cohort of patients is ...eribulin, which in addition to its antimitotic effect has an effect on the tumor microenvironment. The search for biological criteria that will allow predicting the effectiveness of the drug is assumed relevant since it will help to select patients who may receive the most benefit from certain therapy regimens.
Objective
: identification of immunological predictors of the therapeutic effectiveness of eribulin in patients with locally advanced or metastatic triple-negative breast cancer.
Materials and methods
. The study included 20 patients with locally advanced and metastatic triple negative breast cancer. 50 % had a short-term response (progression-free survival <3 months) to eribulin therapy, and 50 % had a long-term response (progression-free survival >6 months). Seven-color immunofluorescence was used to determine the subpopulation composition of tumor-infiltrating lymphocytes and their PD1 expression. Image acquisition and analysis were performed using the Vectra® 3.0 system and InForm® software (Akoya Biosciences, USA).
Results
. It has been shown that the ratio of the number of PD1-negative to PD1-positive CD20+ B-lymphocytes less than 5.5 associated with the long-term effectiveness of eribulin in patients with locally advanced or metastatic triple negative breast cancer.
Conclusion
. The results showed that the ratio of the number of PD1-negative to PD1-positive CD20+ B-lymphocytes can be considered as a possible marker to predict the effectiveness of eribulin in patients with breast cancer.
Analysis of the incidence of human brucellosis in the world in 2011–2020 is presented in the paper. An assessment of the epizootiological-epidemiological situation on brucellosis in the Russian ...Federation in 2020 is performed. It is outlined that the epidemiological situation on brucellosis in Russia over the past decade was characterized as unfavorable with downward trend in the incidence rate against the background of persistent epizootiological insecurity among cattle and small ruminants. Between 2011 and 2020, 3507 first identified human cases of brucellosis were registered. The long-term average number of cases is 350 per year, including 28 cases among children under 17 years old. The average long-term intensive morbidity rate per 100 000 people was 0.24, among children under 17 – 0.1. In 2020, 119 human cases of brucellosis were detected in Russia (0.08), which indicates that the trend towards an improvement in the epidemiological situation on brucellosis continues. The largest number of brucellosis cases among people was registered in the North-Caucasian (77.1 % of the total incidence across Russia) and the Southern Federal District (13.5 %). In the period of 2010–2020 (9 months), 4610 areas potentially hazardous as regards bovine brucellosis and 422 – as regards brucellosis in sheep and goats were registered in the Russian Federation. Analysis of the development of brucellosis situation in Russia indicates that in the medium term, with the current trend maintained, there is a real risk of widespread brucellosis distribution among farm animals in the constituent entities of the Central, Volga, Far Eastern and Siberian Federal Districts, as well as the persistence of epizootiological insecurity in the North Caucasus and Southern Federal Districts. Taking into account the current epizootiological-epidemiological situation and the long-term dynamics of the development in the Russian Federation, one can predict the incidence of brucellosis in people at a level below the longterm average values – 0.13–0.18 per 100000 of the population in 2021.
In order to develop the most diagnostically informative methods for carrying out antigen-stimulated cellular tests in vitro a careful selection of stimulating agent (antigen) is required, possessing ...an adequate activating potential and providing specificity of the reaction.
Objective
of the study was to identify the qualitative indicators of experimental batches of brucellosis antigen preparations designed for cellular tests in vitro.
Materials and methods
. Initially we produced antigen complexes of brucellosis microbe on the basis of the vaccine strains of three epidemically significant Brucella species (B. abortus, B. melitensis, B. suis). Quantitative determination of WsAg and PPBC proteins of experimental preparation series was performed applying capillary electrophoresis. Qualitative composition was assessed through ion exchange liquid chromatography with refractometric detection.
Results and discussion
. We have specified physical-chemical features, investigated chromatographic profiles and composition of protein fractions, as well as tried the produced experimental batches of brucellosis antigen preparations. After analyzing the defined protein and polysaccharide composition of the obtained WsAg samples, one can conclude that WsAg preparation cannot be used for cellular tests as the probability of non-specific lymphocyte reaction manifestation in vitro was experimentally proven. By contrast, complex brucellosis antigen preparation PPBC has an expressed specific activity and specificity under in vitro conditions and the prospects to be used when developing methodological approaches for laboratory diagnosis of brucellosis and assessment of de facto immunity rate in risk contingents after vaccination. The obtained parameters will allow for proper quality provision when manufacturing the developed experimental PPBC preparation designed for cellular tests in vitro, taking into account modern validation and standardization regulations.
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