We present recent advances in studying the mechanisms of susceptibility to immune-mediated uveitis (IM) and its pathogenesis. Animal models of human uveitis are described in details. Those include the best characterized models of experimental anterior uveitis (endotoxin-induced uveitis and experimental autoimmune anterior uveitis). As a result of these studies, some relevant transcription factors were detected, such as STAT3, Interferon regulatory factor 4, 8; regulatory proteins, e.g., suppressors of cytokine signaling 1, 3 (SOCS1, SOCS3) and cytokine signaling pathways that regulate the development of IS and may serve as potential therapeutic targets for treatment. Environmental risk factors contributing to the development of IS are also characterized. The presented data concern the influence of physical activity, smoking, state of intestinal microbiome, and diet on the incidence of IS, as well as known and suspected contribution of the risk factors to the initiation and pathogenesis of the disease. In particular, we present results of studies which suggest two main options of intestinal microbiome involvement in the IS development: intestinal microbiome antigens act as triggers for activation of T cells specific for retinal antigens, and the microbiome modulates the balance of effector subpopulations of T lymphocytes (Th1 and Th17) and immunoregulatory subpopulations cells (Treg). It is reported that high levels of expression of ocular proteins (interphotoreceptor retinoid binding protein – IRBP or S-antigen) in the thymus correlated with resistance to the development of EAU, while low IRBP levels correlated with susceptibility to uveitis. These seminal studies in pathogenesis of IU allowed explanation for selective susceptibility to autoimmune uveitis and suggested regulation tools of resistance to uveitis, at least, in part, due to ability of maintaining central tolerance to retinal autoantigens. Uveitogenic memory T cells have been described to move from retina and peripheral lymphoid tissues to the bone marrow, remaining there in a quiescent state until re-stimulation, then transforming into various subpopulations of effector cells. Analysis of immunological studies in murine models of uveitis and peripheral blood of patients with uveitis had revealed a pathogenetic role of Th17 lymphocytes and a transcription activator STAT3 in development of autoimmune uveitis, with STAT3 signaling protein being a potential therapeutic target for non-infectious uveitis.

Immune checkpoints (ICs) represent a broad set of stimulatory and inhibitory signaling pathways playing an important role in regulation of immune responses. Initially, ICs have been considered solely as cell membrane-bound receptor and ligand systems, triggering or blocking immune cell function. Over the past decade they have been proven to exist in soluble forms (sICs). sICs are biologically active regulators involved in paracrine and systemic modulation of immune responses, similar to cytokines. Normally, sICs exert both stimulatory and inhibitory effects on the immune system, and their balance may be disturbed in many malignant neoplasms, COVID-19, HIV infection. There is a lot of data on the connection between sICs and various diseases, but a number of key aspects of their biology have not been fully clarified. The most widely studied are PD-1 (programmed death receptor-1) and its ligands PD-L1 and PD-L2, CTLA-4 (cytotoxic T lymphocyte antigen-4), TIM-3 (T cell immunoglobulin and mucin-domain containing-3), VISTA (V-domain Ig-containing suppressor of T cell activation). The mechanisms of soluble form formation are complex and diverse and include alternative splicing, cleavage of membrane ectodomains, and proteolytic cleavage. The most important molecular mechanisms underlying the synthesis and release of sPD-1 and sPD-L1 are alternative splicing of mRNA and translation of isoforms lacking transmembrane domains, while the formation of sTIM-3 occurs by cleaving the extracellular regions of transmembrane proteins by protease ADAM10. The review article provides data on the main sICs, including sPD-1, sPD-L1, exosomal sPD-L1, sCTLA-4, and several others. The molecular mechanisms of their formation, biological functions in maintaining immune homeostasis, prognostic significance of changes in their content are described in patients with solid malignant tumors (nonsmall cell lung cancer, hepatocellular cancer, breast cancer, kidney cancer, skin cancer, gastric cancer, etc.), as well as for hematologic malignancies (lymphoma, chronic lymphocytic leukemia, acute myeloblastic leukemia, multiple myeloma).

Our objective was to demonstrate the efficiency of therapy for antiphospholipid syndrome (APS) in pregnant women using plasmapheresis and intravenous immunoglobulins.

92 women with diagnosed APS and 47 APS-free women with physiological pregnancy were under study. APS was diagnosed in accordance with Sydney Consensus Workshop (2006). Patients with APS were divided into groups depending on the method of treatment used: conventional therapy, plasmapheresis in addition to standard therapy, intravenous immunoglobulins (IVIG) in addition to standard therapy, and complex treatment, i.e., plasmapheresis and IVIG added to standard therapy. The levels of antiphospholipid antibodies, hemostasis parameters, P-selectin were measured in blood serum and plasma before and after treatment.

Higher frequency of favorable pregnancy outcomes was shown in the group of patients with APS who were treated with combined therapy, i.e. in 96.3% of cases (term birth). Frequency of prematurity and fetal hypotrophy was significantly lower in the group of patients with APS treated with combined therapy. The most significant decrease in the level of antiphospholipid antibodies was observed in the group treated by plasmapheresis, IVIG and conventional therapy. Expression of P-selectin in the women with normal pregnancy without antiphospholipid antibodies, was significantly lower compared to pregnant women with APS.

Usage of integrated approach using plasmapheresis, intravenous immunoglobulins and standard therapy is the most effective treatment for APS-related miscarriage. Implication of this strategy has reduced the incidence of obstetric complications and improved pregnancy outcomes due to increased frequency of term births, as well as lowest indices of pathology in the newborns. Analysis of P-selectin levels before and after treatment enables determination of the platelet activation levels, efficiency of therapeutic approaches, as well as medical drug correction of infavorable platelet hemostasis during therapy.

The aim of this work was to study the capacity of human T cells immune for SARS-CoV-2, to produce IFNγ, a marker of T cell immunity, in response to stimulation by a peptide pool in whole blood. Eighty samples of whole blood were received from the volunteers with known medical history in 2021, and 258 volunteers were examined in September-October 2022. In this study, 2 detection techniques were used, i.e.: (1) solid-phase enzyme immunoassay to determine antibodies of class G to RBD SARS-CoV-2; (2) IGRA test to determine IFNγ produced by antigen-specific lymphocytes in response to their stimulation by viral antigen. The parameters of the IGRA test were optimized with a sample of 80 specimens from the volunteers. The threshold value of the IFNγ level was determined (4.85 pg/mL), at the diagnostic specificity of 100% (80.6-100), and diagnostic sensitivity of 92.19% (83-96.6%), 95% CI. The study was further continued with a sample of 258 volunteers. Of them, 28.7%, did not exceed the threshold level of IFNγ after stimulation, according to results of the IGRA test. Meanwhile, all volunteers exhibited class G antibodies to RBB SARS-CoV-2. There was no correlation between the levels of antibodies and the level of interferon response in the entire group. When comparing IgG antibody levels and the amplitude of IFNγ (if exceeding the baseline level) in the groups differing in the time of the last vaccination, the median values of the parameters were slightly higher for the subgroup which was revaccinated 1-2 months before the study, while a significant difference between these subgroups was revealed only when evaluating IFNγ, pg/mL (Mann–Whitney criterion, p = 0.0321). According to the results of the study, it can be assumed that all the patients in the sample who were vaccinated and had COVID-19 infection, showed a humoral immune response. However, about a third of them lacked cellular immunity to SARS-CoV-2. There was no correlation between the levels of antibodies and the level of interferon response (Spearman’s criterion). Revaccination within previous 1-2 months has been shown to promote the increased amplitude of interferon response.

Uterine leiomyomas (UL) are benign uterine tumors. Hypertrophic increase in muscle mass in LM is accompanied by development of vascular networks, which are regulated by the balance of pro-angiogenic factors, e.g., VEGF-A. Moreover, a number of inflammatory molecules exert pro-angiogenic effects, especially, IL-1β, IL-8, etc. The spectrum of their activity may overlap, being regulated by other cytokines. The aim of our work was to assess serum concentrations of cytokines actively involved in vascular network growth in the patients with multiple uterine fibroids, as compared with data obtained in conditionally healthy women. The survey included 178 females: 89 women (23-60 years old) with uterine fibroids, and 89 conditionally healthy age-matched women (22-61 years old). The levels of TNFα, IL-1β, IL-4, IL-6, IL-8, IL-10 and VEGF-A were detected by ELISA technique (Vector-Best, Russia). Statistical analysis was carried out using the IBM SPSS Statistics 23 (USA). Serum levels of IL-6, TNF and IL-8, were higher among patients compared with healthy women. The dependence of VEGF level on the number of myoma nodes has been established: VEGF serum level was higher in patients with multiple tumor nodes. In healthy women, an increase in TNFα level showed direct correlation with higher serum level of IL-6. Correlation with VEGF level was weakly negative. In leiomyoma, these relationships persist for IL-6, IL-8, VEGF levels. The obtained data are of practical importance not only as potential prognostic criteria for development of the uterine myoma at preclinical stage, but also as additional laboratory indexes for differential diagnostics, in particular when discerning uterine leiomyoma, the most common benign myomatous tumor of uterus, from malignant uterine leiomyosarcomas.

Benz(a)pyrene is a first hazard class aromatic compound which exerts carcinogenic, mutagenic, hematotoxic, and immunotropic effects. The study of cell clusters influenced in vivo by exogenous haptens using laboratory mice as a model object allows us to expand knowledge about the mechanisms and features of immunotropic effects induced by benzo(a)pyrene. The experimental series involved 12 female outbred white mice. The concentration of benzo(a)pyrene for a single dose was 6 μg/L, To neutralize its effects, the Chlorella growth factor (CGF) concentrate was used as an adaptogen, which was consistently administered over 4 weeks at a dose of 60-70 mlns/mL of living cells. Both substances were administered via oral tube in a volume of 1 mL. The study of cell phagocytosis was carried out by the method of V.N. Kaplin. Analysis of the total number of leukocytes and lymphocytes was carried out using a hematology analyzer. The study of cell differentiation clusters was carried out using flow cytometry. Microsoft® Office Excel and Statistica 6.0 programs were used for statistical evaluation. Results: subchronic intoxication with benzo(a) pyrene under the in vivo experimental conditions led to significant modification of cellular immunity, exhibiting a phenotype of deficient innate cellular immunity factors, and imbalance of adaptive cellular immunity with a predominant inhibition of apoptotic activity (CD95⁺) and modeling of integrin- and VEGFmediated events (CD11a, CD309). Sequential intake of the natural modifier (CGF) was characterized by normalization of phagocytic activity and alleviation of benzo(a)pyrene-induced effects. Conclusions of the study are limited by small number of experimental sample, The in vivo experiment have shown an imbalanced pattern of nonspecific and adaptive cellular immunity, associated with granulocyte changes caused by benzo(a)pyrene along with disturbed control of cell proliferation alleviated by CGF. The intake of the CGF complex led to optimization of immune system as shown by a number of indexes, along with positively modified immunotropic effects of benzo(a)pyrene with cancelled suppression of granulocytic and integrin-associated lymphoid lineages, which provides, mostly, phagocytosis protection, as well as antiapoptotic and integrin-mimetic effects.

Alcohol intake during pregnancy may affect the normal course of fetal development, causing the symptoms of fetal alcohol spectrum disorders (FASD). There is evidence that a number of prenatal pathologic conditions exhibit altered expression of several pro- and anti-inflammatory cytokines. In our study, we focused on studying expression of numerous pro- and anti-inflammatory cytokine genes in the forebrain and temporal regions of rat brain during the postnatal development, thus modeling prenatal alcohol exposure effects (PAE). We also evaluated expression of genes associated with regulation of genes controlling expression of pro- and anti-inflammatory cytokines. Moreover, the objectives of our study included pharmacological correction of the observed changes by rifampicin (Rif), a potential pharmacological agent which had a neuroprotective effect shown by other studies,. The experimental model of PAE was produced by oral intake of 15% ethanol solution to pregnant female rats throughout pregnancy. The drug injections were performed to the pups from the 1 to the 7 postnatal days. Brain structures were sampled for gene expression analysis on the 8 postnatal day. The results of the study showed distinct changes in Tlr3 and Tlr4 gene expression in anterior and temporal lobes of brain on the 8 day of postnatal development. Expression of Myd88 and Ticam genes showed multidirectional changes among the studied brain structures of PAE rats. The increased mRNA level of proinflammatory genes was noted. Usage of Rif in experiments showed the ability of Rif (50 mg/kg) to correct the observed long-term pathological changes in the expression of the genes under study. It is of interest to study the dose-dependent effect in the future, as well as to investigate the revealed changes at the level of protein analysis. In future studies, it seems important to evaluate TLR signaling system in other brain structures with PAE, as well as at different terms of postnatal development in ontogenesis.

Psoriasis is the most common inflammatory skin disease, affecting on average 2-4% of the world’s population. Currently, psoriasis is considered a multifactorial disease occurring in genetically predisposed individuals under the influence of various environmental factors that trigger a disrupted immune response via complex inflammatory cascades. The disease is initiated and maintained by the mutual interaction of cells of innate and adaptive immunity, primarily, dendritic cells, T lymphocytes and keratinocytes. Their leading role may alternate at different stages of the disease and proceeds, mainly, at the IL-23/Th17 pathway. To date, many gene polymorphisms (SNPs) associated with the development of psoriasis have been described. To understand the pathophysiology of psoriasis as a complex autoinflammatory disease, it seems interesting to study the intergenic interactions between polymorphic gene variants of cytokines and C-reactive protein related to the risk of psoriasis development. The aim of our study was to investigate intergenic interactions of polymorphic variants of IL1β (rs16944), IL6 (rs1554606), IL8 (rs2227306), IL10 (rs1800896), TNFα (rs361525), CRP (rs1205) genes associated with altered risk of psoriasis development among the Kemerovo Region residents. We examined 175 patients with ordinary papular plaque psoriasis of moderate severity, with progressive course of the disorder. The control group (n = 155) was recruited from conditionally healthy, age-matched donors. Genotyping was performed by PCR using TaqMan probes (Thermo Fisher Scientific, USA), by means of the detection amplifier ViiA^TM 7 Real-Time PCR System (Life Technologies, USA), for the following polymorphic variants of genes: IL1β (rs16944), IL6 (rs1554606), IL8 (rs2227306), IL10 (rs1800896), TNFα (rs361525), CRP (rs1205). Intergenic interactions were analyzed using Multifactor Dimensionality Reduction (MDR). The common papulosis-plaque psoriasis was found to be associated with individual polymorphic variants of cytokine and CRP genes as well as with gene-gene interactions. Concerning individual polymorphic gene variants, the association strength (% entropy) with common papulosis-plaque psoriasis was as follows: TNFα_ rs361525 (16.99% entropy), IL1β_rs16944 (6.40% entropy), CRP_rs1205 (2.55% entropy), IL6_rs1554606 (1.11% entropy), IL10_rs1800896 (0.57% entropy), IL8_rs2227306 (0.30% entropy). We have found that IL6 (rs1554606) and IL8 (rs2227306) showed marked synergism, as well as moderate synergism of CRP (rs1205) and IL10 (rs1800896), and pronounced antagonism of IL1β (rs16944) and TNFα (rs361525).

There is a direct association between the functional, morphologic and biochemical atypic features of cellular tumor expression and malignancy. Five molecular-genetic subtypes of breast cancer are recognized. The most aggressive course is known to be characterized by non-luminal subtypes, in particular, a triplenegative breast cancer. The aim of this research is to determine the association between the percentage of the cells showing distinct differentiation types, and cytokine production by breast cancer bioptates in both luminal and non-luminal breast cancer subtypes. Bioptates of 49 women with the invasive breast carcinoma of nonspecific type, at the average age of 59 years, were used as the material for the study. The patients were divided into three groups according to the molecular-genetic subtype of cancer. Group I included patients with luminal subtype A, group II – with luminal B and group III – with non-luminal subtypes of breast cancer. Spontaneous and in vitro stimulated by polyclonal activators production of cytokines was evaluated. The level of cytokineproducing reserve by the biopsy specimens was expressed as the influence index of polyclonal activators, due to its accuracy, thus making it possible to avoid errors due to the similar sizes of bioptates from each patient and their incubation conditions. The percentage of tumor cells of varying degrees of differentiation in the samples was assessed using light microscopy by means of the Nottingham grading system. When assessing spontaneous and stimulated production of cytokines, as well as degree of cell differentiation of tumor samples, direct and reverse correlations were revealed between the study groups. The most important parameter was the influence index of the polyclonal activator which characterized production of IL-10 and VEGF-A by the bioptates. Therefore, we can provide personalized information for each patient, in particular, for these two cytokines, even before starting the treatment.The analysis of ROC-curves showed good quality and optimal level of cytokine concentration and percentage of low-differentiated cells. This approach could predict the presence of unfavorable non-luminal breast cancer subtypes in the best way. In general, we can make a conclusion that cytokine-producing reserve is connected with cellular differentiation and depends on molecular-genetic subtype of the tumor.

Despite numerous separation methods of neutrophils from peripheral blood, isolation of sufficient quantities of high-purity viable cells for quantitative determination of neutrophil cytokines and their mRNA expression still remains an actual issue. The recommended multi-step purification methods significantly prolong the cell isolation process, potentially leading to cell activation or apoptosis and resulting in significant cell loss. Preliminary purification of neutrophils is the most critical stage in terms of time spent, and several additional manipulations with cells. To address this challenge, our study aimed to compare various methods of preliminary neutrophil isolation in order to select the optimal approach to obtaining a sufficient number of viable peripheral neutrophils.

We studied the effects of three different protocols for preliminary isolation of cell suspensions: (a) centrifugation of whole blood at a single-step density gradient followed by sedimentation of red blood cells with dextran; (b) centrifugation of whole blood on a double density gradient; (c) rapid isolation of leukocytes using a reagent that promotes red blood cell aggregation. The cell counts and viability of purified neutrophils were tested at the final stage using negative immunomagnetic selection. Our study has shown that the methods used for preliminary neutrophil isolation significantly affect both the number and viability of the cells. The highest number of viable neutrophils was obtained using a conventional method of blood centrifugation at a density gradient followed by dextran sedimentation of red blood cells. However, the three studied methods of preliminary neutrophil isolation did not show statistically significant differences with respect to quantitative yield of viable cells after immunomagnetic isolation. These findings suggest that any of these methods may be applied, depending on capabilities and preferences of the researchers. In summary, our findings confirm previous studies indicating that the multistep process of neutrophil isolation allows for obtaining a high-purity cell suspension (> 99.1%) which can be used in future studies of their cytokine-secreting activity. However, such multi-stage isolation significantly reduces the yield of neutrophils, thus being critical for studying of initially small blood volumes.

Chicken egg is among the most important sources of allergens. Sensitization to them is most often manifests as food allergy (FA), and/or atopic dermatitis (AD). Immunogenic substances of a chicken egg are present in both white egg and yolk.

The purpose of our work was to compare frequency and intensity of the IgE responses to various components of a chicken egg in children, depending on their age and gender. We examined 3070 children with symptoms of food allergies and atopic dermatitis, analyzed the IgE responses to chicken white egg allergens extract (f1) and yolk allergens extract (f75), taking into account the age and gender of children. The IgE levels were determined by immunofluorescence using an automatic ImmunoCAP 250 analyzer. We found a high incidence of sensitization to chicken egg in children with FA and AD: 31.07% (n = 954) of patients had clinically significant IgE levels. The frequency of sensitization to white egg was statistically significantly higher than the frequency of sensitization to yolk: 31.04% (n = 953) and 13.13% (n = 403), respectively. The maximum prevalence of positive IgE responses to white egg and yolk and more severe sensitization were observed in children of their first year of life. A significant decrease of these indices has been detected in groups of older children. In older age groups, there was also a decrease in the number of co-sensitized patients, whereas the number of monosensitization cases to chicken egg protein was increased in groups of children of 2 to 6 years old, and then decreased in children over 6 years old. The frequency of positive IgE responses to allergen extracts of white egg and yolk did not differ significantly and had similar age dynamics in children of both sexes. Statistically significant differences between the IgE responses of boys and girls were found only in groups of children over 14 years old, especially with IgE to allergens of white egg. We have shown an extremely low frequency of monosensitization to yolk: clinically significant levels of IgE to yolk in the absence of antibodies to egg protein were found in 0.1% of patients with food allergies and atopic dermatitis. High frequency of sensitization to chicken eggs in small children suggests an extremely early contact of the patients with allergens. The immunogenic ability of white egg and yolk allergens is different. Much more pronounced IgE response was observed towards white egg. A decreasing number of positive IgE response cases to chicken egg allergens in children may be due to development of immunological tolerance to both yolk and white egg at the age of 8-10 years. However, the issue of studying the allergic response mechanisms remains open, since, despite a significant decrease in prevalence of egg allergy in older children, a number of patients still do not achieve tolerance to this food product.

In this work, we determined the content of antibodies to low-density lipoproteins modified by malondialdehyde, the concentration of circulating immune complexes cholesterol and oxidized low-density lipoproteins in the blood of healthy individuals and patients with various manifestations of atherosclerosis. In addition, the effect of antibodies to low-density lipoproteins modified with malondialdehyde on the interaction of such lipoproteins with macrophages was studied. 253 persons were examined: healthy individuals (59 people), patients with preclinical atherosclerosis (25 people) and patients with coronary artery disease (169 people). It was found that the concentration of circulating immune complexes cholesterol in plasma was increased in patients with coronary artery disease compared with healthy individuals and patients with preclinical atherosclerosis, while oxidized low-density lipoproteins content did not differ between patients groups. At the same time, a positive correlation oxidized low-density lipoproteins plasma concentration with circulating immune complexes cholesterol content was found in patients with atherosclerosis. The plasma level of IgG antibodies to malondialdehyde-modified lipoproteins was significantly reduced in patients with coronary artery disease compared with healthy people and patients with preclinical atherosclerosis. While the level of IgM antibodies to malondialdehyde low-density lipoproteins practically did not change in patients with atherosclerosis independently of disease severity. It was shown that specific antibodies vastly reduced malondialdehyde low density lipoproteins cytotoxicity and ability to induce cholesterol esters accumulation in macrophages derived from human peripheral blood mononuclear cells. Thus, the data obtained indicate that anti-lipoprotein antibodies may have a protective effect by preventing cell death and reducing the accumulation of cholesterol esters in macrophages when they interact with modified low-density lipoproteins, i.e. prevent the foam cells formation.

Potential involvement of immune system in pathophysiology of congenital glaucoma, cataract, and retinopathy of prematurity (ROP) in infants has been suggested. However, its understanding still remains limited. T regulatory cells (CD4⁺CD25^highFoxP3⁺CD127^low), with their role in autoimmunity, are considered pivotal in this respect, although there is a scarcity of publications in this context. This study aims to address this gap. Our purpose was to compare the levels of blood cells with (CD4⁺CD25^highFoxP3⁺CD127^low) phenotype in infants with ROP, congenital glaucoma and cataract, and healthy full-term infants. This retrospective case-control study included 131 infants (262 eyes). Inclusion criteria were as follows: age under 12 months and a confirmed diagnosis of congenital cataract (20 eyes), congenital glaucoma (21 eyes), and ROP (158 eyes). The control group consisted of 27 full-term infants (54 eyes) with normal eye exam. Primary outcomes included study of Treg cells (CD4⁺CD25^highFoxP3⁺CD127^low) levels in all groups. Secondary outcomes involved the correlation between the CD4⁺CD25^highFoxP3⁺CD127^low subpopulation and weight at birth. According to our previous studies and when comparing the results in the present study of children under 1 year of age, we found significant differences in the number of T regulatory cells (CD4⁺CD25^highFoxP3⁺CD127^low) between premature and full-term children, as well as in the patient groups with cataract and glaucoma by their weight category. The authors were able to detect differences between stages of retinopathy of prematurity by the number of T regulatory cells (CD4⁺CD25^highFoxP3⁺CD127^low), distinguishing posterior aggressive retinopathy of prematurity as a special form of this pathology. The reduced levels of CD4⁺CD25^highFoxP3⁺CD127^low cells in infants with ROP type 1 suggests autoimmune reactions in its pathophysiology. The remarkable difference in (CD4⁺CD25^highFoxP3⁺CD127^low) Treg cells in patients with congenital glaucoma and cataract may indicate immune-mediated mechanisms in their development. The clinical significance of the revealed correlation between the level of studied T cells and birth weight in infants with cataract and glaucoma is not clear and requires further investigation with regard to the disease severity. The index can be used as a potential prognostic marker of the disease course and visual outcomes. Collectively, this study provided valuable insights on the potential targets for novel treatment strategies in infants with ROP, glaucoma, and cataracts.

Lassa hemorrhagic fever is an acute human infectious disease with high mortality rate and pandemic potential. To date, there are no approved drugs for the specific treatment or prevention of Lassa hemorrhagic fever in the world. The aim of this study was to develop and evaluate the immunobiological properties and preclinical safety of a candidate vaccine for the prevention of Lassa hemorrhagic fever (LHF) based on recombinant human adenoviral vectors. Standard genetic engineering techniques, molecular biology techniques, virological methods, and animal testing procedures were used in the course of the study. A combined vector candidate vaccine for the prevention of Lassa hemorrhagic fever has been designed and characterized. The vaccine is composed of two components for heterologous immunization in a prime-boost regimen. Both components are based on recombinant replication-defective adenovirus vectors. The first component of the vaccine is a recombinant human adenovirus type 26; the second component is a recombinant human adenovirus type 5. Both recombinant vectors contain the codon-optimized sequence of Lassa virus glycoprotein. Two experimental batches of the candidate vaccine were produced under GMP-conditions and analyzed. The results of studies in compliance with appropriate specifications for viral vector vaccines are provided. In preclinical studies in mice, antigen-specific IgG response was detected after immunization with two vaccine components, either separately, or in a prime-boost regimen. The time dynamics of the IgG response was also studied on 42, 77, 119 and 147 days after immunization. At the same time, despite achieving 100% seroconversion, no virus neutralizing antibodies were detected in any of the samples collected from immunized mice. A biodistribution study showed that 24 hours following intramuscular injection of the vaccine components, the DNA of adenovirus vectors was detected only at the site of injection and in regional lymph nodes. Based on preclinical safety assessments (including acute toxicity, chronic toxicity, immunotoxicity, allergenic properties, reproductive toxicity), no contraindications were found for initiation of the candidate Lassa vaccine clinical trials. Taken together, the results demonstrate that the candidate vaccine for prevention of Lassa hemorrhagic fever based on recombinant adenovirus vectors types 26 and 5 is a promising drug for specific immunoprophylaxis.

Influenza vaccination contributes to the favorable course and outcome of COVID-19. The aim of our study was to study the effect of influenza and pneumococcal vaccines on the level of IgG antibodies (AT) to SARS-CoV-2 among medical personnel at the beginning of the COVID-19 pandemic. We present the data on assessment of specific immune response to the influenza virus and SARS-CoV-2 in 266 medical workers 6 months after immunization against influenza and/or pneumococcal infection (without vaccinations against COVID-19) over the 2020-2021, by comparing the results with respective characteristic in 281 employees with no history of vaccinations is presented.

We have found that the proportion of medical workers with a protective (≥ 1:40) antibody levels to influenza virus 6 months after vaccination in groups of participants reaches a protective (≥ 70%) value only in persons who received a monovaccine against pneumococcal infection (78.6%) as compared with persons vaccinated with a monovaccine against influenza (61.7%) (p < 0.001), as well as with a group of workers immunized against influenza in combination with the S. pneumoniae vaccine (68.9%) (p < 0.01). Hence, the pneumococcal vaccine is able to induce the synthesis of IgG-AT to influenza virus reaching protective values.

An analysis of the group with seropositivity to influenza virus (IgG-AT ≥ 1:10) and their comparisons with persons seroprevalent to COVID-19 showed that the proportion of seropositive individuals among medical staff vaccinated against seasonal influenza after 6 months (indicating a probable asymptomatic form of COVID-19) is increased. It comprised 65.4% (p = 0.026) in the group vaccinated with mono-flu, and 64.5% (p = 0.04) in the group vaccinated with combined influenza and pneumococcus, being higher than among the non-immunized workers (48.8%).

In summary, the results of our study show that influenza vaccination acts as an inducer of humoral immunity not only to the influenza virus, but also to the recently transmitted SARS-CoV-2 infection.

Rearrangement of the immune system during pregnancy is a strictly controlled, dynamic process in which the first and third trimesters are, respectively, pro-inflammatory, and anti-inflammatory periods. However, monocyte involvement in regulating the pro/anti-inflammatory balance remains poorly understood. The functional phenotype of monocytes is known to depend on their subsets assessed by CD14 and CD16 expression, and is associated with expression of M1(CCR2)- and M2(CD206) molecules, associated with pro- and anti-inflammatory activity, respectively. Here we have investigated the expression of CCR2 and CD206 in classical (CD14⁺⁺CD16^- , cMo), intermediate (CD14⁺⁺CD16⁺, iMo), and non-classical monocytes (CD14⁺CD16⁺⁺, nMo) in pregnant women at different gestational ages in comparison with nonpregnant women. The study included 14 pregnant women in the first trimester, 20 in the second trimester, 26 in the third trimester, and 29 fertile non-pregnant women. One-way analysis of variance in these groups revealed significant differences CCR2 and CD206 expression (more pronounced in classical and intermediate monocytes and stronger in relation to CD206 expression). Overall, monocytes from pregnant women had decreased CCR2- and increased CD206 expression, suggesting a shift towards an anti-inflammatory profile. These changes appeared in the first trimester (increased CD206 mean fluorescence intensity [MFI] in cMo and iMo, p < 0.05) and reached their maximum in the second trimester, manifested by significant increase in CD206 and decrease in CCR2 expression (% of cells, MFI) in all monocyte subsets. In the third trimester, CD206⁺ cMo decreased, as compared to the second trimester (p < 0.05), and the percentage of CCR2⁺ cMo and iMo increased. Of note, these changes in the first and third trimesters were combined with increased pro-inflammatory expression profile of non-classical monocytes which was restricted by the non-classical monocyte subpopulation in the first trimester, then being mediated by intermediate and non-classical monocytes in the third trimester. The data obtained suggest involvement of monocytes in regulation of the pro- and anti-inflammatory balance during pregnancy, with predominant development of the M2 profile in classical monocytes during the first and third trimesters, and in all monocyte subsets over second trimester, along with increase in the M1 proinflammatory profile of intermediate and non-classical monocytes in the first and third trimesters.

Development of ulcerative colitis (UC) is accompanied by activation of the purinergic signaling pathway and an increased level of extracellular adenosine. Adenosine is involved in regulating the balance of pro-inflammatory T-helper type 17 (Th17) cells and immunosuppressive regulatory T-cells (Treg), Their disturbance is believed to be one of the main immune factors causing this disease. However, expression of genes encoding Treg cell and Th17 transcription factors (FOXP3 and RORγ, respectively) and genes encoding members of the CD39/CD73/A2AR signaling pathway (ENTPD1, NT5E, ADORA2A) in peripheral blood has not been studied enough. The purpose of our study was to evaluate the expression levels of ENTPD1, NT5E, ADORA2A, FOXP3 and RORγ genes in ulcerative colitis (UC). Thirty-eight patients were examined including 20 patients diagnosed with UC (15 patients on a basic therapy with 5-ASA derivatives, UC1 group); 5 patients treated with Prednisone (group UC2), and 18 apparently healthy people. Total RNA was isolated from peripheral blood leukocytes (PBLCs). The levels of gene transcripts were studied by real-time PCR technique. The ENTPD1 gene mRNA content in UC patients on a basic therapy with 5-ASA derivatives was higher than in healthy people (p = 0.0045). The levels of NT5E and ADORA2A transcripts in the PBLCs of patients in the UC1 group were higher than those of patients in the UC2 group (p = 0.0486 and p = 0.0289, respectively) and healthy individuals (p = 0.0007 and p < 0.001, respectively). The mRNA content of FOXP3 gene in PBLCs of the UC1 group of patients was higher than in conditionally healthy individuals (p = 0.0093). The level of RORγ gene expression in PBLCs of the patients from UC1 and UC2 groups was higher than in healthy individuals (p = 0.0005). Increased levels of FOXP3 and RORγ gene expression (the transcription factors of Treg and Th17 cells, respectively), were observed in PBLCs of UC patients on baseline therapy, whereas expression levels of these genes in prednisolone-treated UC patients did not differ from controls. Correlations between the expression levels of some genes under study were revealed in control persons and in the UC1 group.

The purpose of the present study was to evaluate the effect of DEFB1-20G>A and the DEFB1- 52G>A gene polymorphisms on the expression of DEFB1 in military-age patients with a history of communityacquired pneumonia. A survey of 160 unrelated patients of military age (18-20 years), Caucasian origin was carried out. The first group (n = 80) included the patients with COVID-19 infection complicated by mild pneumonia (n = 40) and severe pneumonia (n = 40). The second group was taken for clinical comparison (n = 80) included the patients with acute respiratory infection (ARI) of non-influenza etiology, complicated by mild pneumonia (n = 40) and severe pneumonia (n = 40). The control group consisted of 86 practically healthy men of the same age. Exclusion criteria were as follows: presence of family relations; patients with acute and/or chronic concomitant pathology. Research methods included clinical laboratory techniques (immunological testing of DEFB1 using a set of ELISA reagents Cloud-Clone Corp. (USA); genetic (polymorphism of the DEFB1-20G>A gene, DEFB1-52G>A gene) with standard primer sets of Litech-SNP (Russia); instrumental examination (computed tomography). The studies were carried out upon admission to the hospital. Statistical evaluation was carried out using the IBM SPSS Statistics Version 25.0 software package (IBM, USA). Predominance of -20A- alleles and genotypes was established -20A/A and -52A/A of the DEFB1 gene variants in the patients with development of severe pneumonia associated with COVID-19 infection. There was an increase in the DEFB1 content in the group with COVID-19 infection by 1.1 times compared with the ARI group, and a 1.5-fold increase against the control group. The changed levels of DEFВ1 associated with severity of community-acquired pneumonia were also characterized by its 1.7-fold increase in the group with a severe clinical course in presence of COVID-19 infection, and by 1.2 times in patients with ARI. The DEFB1 concentration increases significantly in the carriers of DEFB1 -20A/A and -52A/A genotypes. In patients of military age with community-acquired pneumonia, an increased concentration of DEFВ1 is registered, with highest values observed in the group with severe pneumonia due to COVID-19. Carriage of -20A/A and -52A/A genotypes of DEFB1 gene is associated with increased contents of DEFB1. Presence of -20A alleles, -20A/A, and -52A/A genotypes of the DEFB1 genes is associated with severe community-acquired pneumonia associated with COVID-19 infection in patients of military age.

Recent studies have demonstrated increased interest in development of new laboratory methods for assessing the risk of thromboembolic complications in atrial fibrillation. Soluble thrombomodulin (sTM) is one of the biomarkers that exhibit important anti-inflammatory, anticoagulant and antifibrinolytic properties and are involved in maintenance of vascular homeostasis. Our objective was to study the contents of soluble thrombomodulin (sTM) in blood serum of the patients with non-valvular atrial fibrillation receiving anticoagulant therapy with a history of thrombotic complications versus a group of patients with atrial fibrillation without thrombotic complications. The study included 60 patients over 18 years of age diagnosed with atrial fibrillation, which was verified according to clinical recommendations, who received anticoagulant therapy. Of this group, 21 patients developed thrombotic complications during adequate anticoagulant therapy. 22 healthy volunteers were also included into the study. Evaluation of soluble thrombomodulin in blood serum was carried out by ELISA technique using the facilities at the Center for Collective Use “Medical Genomics” of the Tomsk National Research Medical Center. All the examined patients were divided into 2 groups: a group of patients with atrial fibrillation without thrombotic complications (TC), and a group of patients with atrial fibrillation who developed TC. The sTM content in blood serum of patients with thrombotic complications was reduced, when compared with results obtained in patients without thrombotic complications, and among healthy volunteers. Analysis of the sTM level in men and women in groups of patients and in healthy volunteers showed that the values of this serum biomarker were lower in female patients with atrial fibrillation and TC, when compared with women from the group of patients without TC and with healthy females. Moreover, the content of soluble thrombomodulin prove to be reduced in men with thrombosis compared to healthy males. A comparative analysis of sTM levels in women and men in all groups did not reveal statistically significant differences. In the studied group of patients with non-valvular atrial fibrillation receiving anticoagulant therapy, a decrease in sTM levels was noted in the subgroup of patients with TC.

Atopic dermatitis (AD) is a chronic inflammatory skin disease, its pathogenesis is associated with immunological disorders and genetically determined defects of the epidermal barrier. Exposure to aeroallergens, including pollen, plays a crucial role in the exacerbations and progression of AD. When individuals sensitized to pollen allergens come into contact with these allergens, a T2 immune response is activated, characterized by the release of cytokines IL-4, IL-13, and IL-31, which stimulate the production of IgE. This leads to enhanced inflammation, improved penetration of allergens through the compromised epidermal barrier, and activation of keratinocytes and dendritic cells, further impairing the skin barrier function and exacerbating AD symptoms. Previous studies have shown that pollen allergens can directly affect the epidermal barrier by activating proteolytic enzymes that break down intercellular connections in the epidermis, increasing its permeability to allergens and pathogens. This study analyzes the impact of sensitization to birch pollen allergens on the AD exacerbation in adult patients living in Moscow and the Moscow region. Birch pollen is a significant allergen capable of triggering exacerbations of allergic diseases, especially in the Northern Hemisphere countries where birch is widely spread. The study included 30 adult AD patients sensitized to birch pollen, and the SCORAD index was used to assess the severity of the disease, combining both objective skin condition indicators and subjective patient complaints (itching, sleep disturbance). Allergological examination was conducted using the ISAC ImmunoCAP allergochip, allowing for the determination of specific IgE levels to more than 100 allergens, including the main birch pollen allergen – Bet v 1. The analysis showed that most patients experienced a significant increase in AD symptoms during the birch flowering period, correlating with the levels of specific IgE to Bet v 1. The study highlights the clinical significance of sensitization to birch pollen as a trigger factor for AD exacerbation, confirming the need to analyze sensitization to pollen allergens to develop personalized approaches to the diagnosis and treatment of AD patients.