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IgA is an important component of the mucosal system of the body. It limits penetration of pathogens into the bloodstream. Inflammatory diseases such as Crohn disease and colitis may be associated with disorders of IgA synthesis. Both B1 and B2 cells are a source of IgA in the intestines. Special attention is paid to B1 cells, which are able to respond to T-independent type 2 antigens and produce natural antibodies. B1 cells produce about 50% of the intestinal IgA including specific antibodies to the components of microorganisms contained in the gastrointestinal tract. The mechanism of IgA formation in the T-independent way is not investigated in details. It was suggested that the γδТ-cells promote switching to IgA synthesis by B1 cells. This assumption may be supported by their co-localization with B1 lymphocytes in the intestinal mucosa, as well as participation, along with B1 cells, in formation of the first-line defense against the pathogens. In addition, the both lymphocyte subpopulations evolve during initial ontogenesis, earlier than “classic” В2 and αβT cells. Therefore, it was suggested that γδT lymphocytes may be involved into the processes of induction and/or regulation of IgM and IgA production by B1 cells in response to TH2 antigens.In the present study, we have shown the effect of γδT cells upon generation of IgM- and IgA-forming B1 cells in response to α-1,3-dextran in vitro. We also studied the dynamics of the mRNA expression for IgM- and IgA-heavy chains by the B1 cells at different terms of in vitro culture.It was found that, during co-cultivation of B1 cells with 20% γδT lymphocytes, there is no increase in the number of dextran-specific IgM-producing cells. The B1 cells exhibited an increase of IgM heavy chain mRNA expression in response to dextran but not in co-cultures. Expression of mRNA for IgM heavy chains in co-cultures was decreased compared to non-treated B-cell cultures. Contrary to the earlier assumption, a presence of γδT lymphocytes in culture did not enhance the formation of IgA producents. The obtained data suggest regulatory properties of the γδТ lymphocytes during the B1 cells response to T-independent antigens.

Pathogenesis of ischemic stroke is actively involved in the system of innate immunity. Under conditions of cerebral ischemia, a number of biologically active substances are released that interact with innate immunity receptors, in particular TLR2 and TLR4, which exacerbate inflammation in brain tissue. Identification of predictor markers at the level of the innate immunity system may foresee the clinical course of ischemic stroke and ensure timely treatment. Our objective was to study expression of TLR2 and TLR4 receptors in peripheral blood leukocytes in patients with ischemic stroke in the dynamics of the disease. 27 people were included in the study. The main group consisted of patients with ischemic stroke of varying severity (n = 19). Patients of the main group were divided into two subgroups: with an NIHSS index value of < 10 (n = 10) and > 10 (n = 9). The control group included healthy donors with no history of acute and chronic inflammatory diseases (n = 8). Peripheral blood leukocytes were used as the test material. To determine expression of the TLR2 and TLR4 genes, RT-PCR in real time was used. Surface expression of TLRs was determined by flow cytometry. A study of the TLR2 and TLR4 gene expression showed that on the 1st, 3rd and 7th day post-stroke, the TLR4 gene expression in patients was significantly increased, when compared to the control group (p < 0.01), whereas TLR2 gene expression on the 3rd day of the disease was not statistically different from the control group. A study of surface expression of receptors showed that the average TLR2 fluorescence intensity on the patients’ peripheral blood monocytes was significantly increased on the 1st and 3rd day of disease when compared to the control group. The surface expression of TLR4 on monocytes has a statistically significant increase only on day 7. Assessment of surface expression of TLRs in subgroups with different severity values by NIHSS showed that patients with a NIHSS index > 10 had a significantly higher level of surface of TLR2 expression over the observation period, while the largest difference in TLR4 expression in the subgroups was observed on the 1st day of the disease (p < 0.05). Patients with ischemic stroke showed an increase in TLR2 and TLR4 expression at the gene and protein level, compared to healthy donors. These indices can be considered possible predictors for clinical prognosis of ischemic stroke.

Secondary bacterial infections after influenza virus infection further increase morbidity and mortality due to influenza. Despite of seasonal influenza vaccination, antiviral drugs and antibiotics are widely used in viral/bacterial pneumonia therapy. Therefore, further comprehensive study of the infection pathogenesis is relevant. Murine models for influenza virus infection were reproduced with different virus subtypes A/California/04/2009MA (pandemic H1N1 2009), A/Puerto Rico/8/34 (H1N1) and A/Aichi/2/69 (H3N2), Anadyr/177/2009 (H1N1) and for post-influenza bacterial pneumonia caused by the Gram-positive Staphylococcus aureus . After the infection occurs, its pathogenic features were detected by daily monitoring the mortality (survival) and morbidity rate (body weight loss) and, in addition, viral pathogenesis also was evaluated by assessing virus replication (viral titer) and humoral immune responses (production of pro- and anti-inflammatory cytokines) in respiratory tract of infected mice including during antiviral (oseltamivir) and antibacterial (cefuroxime) therapy. Mortality and virus titer in the infected mice did not differ significantly between the groups of different influenza A virus subtypes. However, production of cytokines (IL-10, IFNg, TNFa) and weight gain proved to be different. Mortality of the mice reached 100% after secondary bacterial infection, whereas IFNg and TNFa levels in mice lung increased reached maximal values in the treated groups. Viral subtype A/California/04/2009MA of influenza A was most pathogenic in mouse model of secondary bacterial pneumonia. Antiviral and antibacterial treatment caused a decrease in mortality, reduced viral titers in lungs, and retain body weight gain of mice. According to these points, the treatment groups did not significantly differ from each other. At the same time, it should be noted that the cytokine production significantly decreased in the treated groups, and IL-10 and IFNg levels in lungs were different, that may be due to therapeutic mechanisms of these drugs. Thus, antiviral therapy for influenza infection and combination therapy for viralbacterial pneumonia can be an effective tool to reduce mortality of influenza.

At the present time, the role of innate immunity in pathogenesis of bronchial asthma (BA) is actively studied, in particular, significance of TLRs and cytokines. The study included 42 patients with severe bronchial asthma (from 3 to 12 years old), and 67 healthy children at the same age. Expression of TLR2, TLR4, and TLR9 genes was evaluated by PCR-RT from the scrapings of nasal mucosa; cytokines (IL-33, TSLP, IL-4, TGF-β1 and IL-28B) were assayed in nasal swabs by ELISA technique. The main results were as follows: an increased gene expression of TLR2, TLR4, TLR9 genes was revealed in the nasal mucosa scraps from the patients with bronchial asthma as compared to healthy children. We have also measured the contents of important cytokines secreted by the respiratory epithelium in the course of TLRs activation. The study of IL-33, TSLP, IL-4 in nasal samples revealed significantly increased concentrations of these cytokines in the patients with severe BA against the control group. A study of TGF-βlevels in nasal cavity swabs revealed a significant decrease of this regulatory cytokine in the group of pediatric patients with asthma. Worth of note, evaluation of antiviral IL-28B cytokine in the group of patients with severe BA showed a significant downward trend, in comparison to the control indexes. Hence, one may conclude on some disturbances of local innate immunity system in the patients with severe BA which manifest as hyperexpression of TLRs genes, increased production of proinflammatory and epithelial cytokines, decreased production of antiviral IL-28B cytokine, and TGF-β1.

The aim of this work was to study features of gene expression TLR2, TLR4, and TLR9 in the course of acute respiratory infection, depending on the time elapsing since the contamination, and dose of infection. The studies of in vivo models of acute respiratory infections caused by Gram-negative Klebsiella pneumoniae showed that, at infection dose of 10 4 CFU/ml, the TLR4 gene expression levels in epithelium of upper respiratory tract at 1, 3, 10 days were increased 30 times and more, complete elimination of the pathogen was observed at 3 days. At the dose of infection of 10 7 CFU/ml, persistence of the pathogen in upper respiratory tract was observed within a few days, accompanied by a significant increase in the level of TLR9 expression in epithelium of upper respiratory tract, and TLR4 levels in the lungs 1 day after infection, in parallel to elimination of the pathogen from the lower respiratory tract. Thus, the characteristic features of TLR4 and TLR9 gene expression in the upper respiratory tract may be considered a potential diagnostic and prognostic factors in evaluation of the course of acute respiratory infections caused by Klebsiella pneumoniae.

The theory of polyetiological tumorigenesis is one of the most important theories of carcinogenesis. A great place in this theory is given to the role of inflammatory component, which is implemented via the factors of innate immunity. I.e., toll-like receptors (TLRs), chemokines and their receptors are related to innate immunity. Activation of TLRs may lead to regress or progression of cancer process. It is known that TLR3, TLR5, TLR7, TLR9 have the greatest anti-tumor effect due to the dendritic cells (DCs)-mediated activation of type I T helpers, activation of M1-type macrophages and Treg inhibition. Stimulation of TLR2 and TLR4 exerts an activating effect upon the tumor, by the MyD88 hyperactivation and secretion of IL-6 and TNFα, but exact mechanisms are not fully understood. In addition to TLRs, chemokines and their receptors have a great influence on the cancer development. It is shown that CCL2, CCL4, CCL17, CCL22 and CXCL12, which are secreted by cancer microenviroment, activate chemotaxis of tumor cells. It is also known that the chemokines activate CXCR4 and CCR7 (expressed by tumor cells) thus leading to metastasis. It is shown that there is an association between some gene polymorphisms of TLRs’, chemokines and their receptors, and development of cancer. Thus, we may conclude that the role of TLRs and chemokines is important in oncogenesis. Further study of innate immunity factors influencing tumorigenesis are important for finding new approaches to cancer therapy and new potential vaccines against cancer.

Currently actively discussed the role of innate immunity receptors, in particular TLRs in the immunopathogenesis of bronchial asthma (BA). The aim of our work was to study the expression of ТLR2 and TLR4 on the nasal mucosal cells and peripheral blood leukocytes of patients with BA of different severity. The study included 40 children with asthma (3-12 years) and 10 healthy children. Methods: real-time PCR, flow cytometry and multiplex immunofluorescence analysis evaluated the levels of pro and anti-inflammatory cytokines (IL-1β, IL-1ra, IL-6, IL-8, IL-10, TNFα) in nasal swabs. The result of the study hyperactivation of the factors of innate immunity at the level of the mucosal of the nasal cavity in patients with asthma, manifested by increased gene expression of TLR2, TLR4, and production of proinflammatory as well as anti-inflammatory cytokines. Correlation between cytokine levels and the severity of asthma. In the peripheral blood identified a significant increase in the expression of TLR2 and TLR4 on circulating CD14 + monocytes in children with BA. Thus, the increase of gene expression of TLRs mucosa of the nasal cavity, increase surface expression of TLR2 and TLR4 on circulating monocytes of patients with bronchial asthma compared to healthy children. The revealed changes indicate the involvement of the system of TLRs in the immunopathogenesis of bronchial asthma. In the future, TLRs can be used as markers to predict the course of ad and possible therapeutic targets.

The study for quantitation of TLR2, TLR4 and HBD-1 gene expression in urethral mucosal epithelium from women with chronic bacterial cystitis and healthy females. Materials and methods: RNA was extracted from the samples of urethral mucosa followed by RT-PCR. Results: increased expression of TLR2, TLR4 (respectively, 6.9-, 2.6-fold), along with 13.6-fold decrease in HBD-1 was revealed in women with chronic bacterial cystitis, as compared with appropriate parameters in normal women. Six months later, after combined therapy with autologous immunopeptide complex, TLR2, TLR4 и HBD1 expression levels proved to be near-normal in the patients, being similar to those in healthy females. Conclusion: Imbalanced expression of genes controlling innate immunity was revealed in urethral mucosa of the patients with chronic cystitis, thus increasing risk for urinary tract infections.

Specific perinatal infections make about 30% in causal structure of infant mortality. Among the respiratory diseases of perinatal period, pneumonias take a special place, due to higher frequency, severity, complications and adverse outcomes. The aim of this work was to study microflora and factors of innate immunity (TLR2, TLR4, HBD-1, HBD-2, TNFα and NF-kB) at the level of the mucous membranes of the upper respiratory tract during intrauterine infection of fetus and perinatal pneumonia. Causal structure of ventilator-associated pneumonias at the intensive care unit represents a broad spectrum of pathogens with high resistance to antibiotics. Changes of immunological parameters (recognizing structures, i.e., TLR2, TLR4, HBD-1; HBD-2 defensins; proinflammatory TNFα cytokine and NF-kB transcription factor) in patients with intrauterine infections and pneumonia are ambiguous. Decreased expression of TLR2, TLR4 genes, along with increased of TNFα and NF-kB gene expression. These changes correlate with type of infectious pathogen, thus allowing us to assume that the pathogen, due to pathogenicity factors, may directly affect innate immunity mechanisms.

Toll-like receptors (TLR) are involved into innate immune recognition of microorganisms, including pathogenic bacteria. The aim of this work is to assess relative levels of TLR2 and TLR9 expression in cervical epithelial cells of women with inflammatory diseases of pelvic organs. The total group of patients consisted of 47 persons, including 20 women with urogenital infections, and 27 women comprised a control group. Using real-time PCR, we identified the opportunistic pathogens and gene expression levels of TLR2, TLR9 in the cervix epithelial cells. It was shown that expression of TLR9 in the group with urogenital infections was 13.7-fold higher than in control group. We have revealed that a significant increase of TLR9 expression in the mucosal epithelium from cervical canal correlated with detection of infectious pathogens in the samples.

Treatment of malignant tumors is among challenging issues of clinical medicine. Dissemination and matestasis of tumor cells plays a major role in oncology, being immediately dependent on chemotaxis of tumor cells. Hence, the aim of our study is to evaluate migration of tumor cells, in terms of ligand-mediated chemotaxis of a human U 937 lymphoma cell line. Synthetic TLR ligands (DNA_lig, RNA_lig) were used as chemoattractants. Assessment of time-dependent TLR expression by the migrating cells (including TLR2, TLR3, TLR7, TLR9) was carried out by means of real-time PCR, using Boyden’s chamber system for the migration assays. We have revealed an increased cell migration towards DNA_ lig and TNFα gradient. Expression of TLR2, TLR7 and TLR9 was found to be increased under the influence of TNFα (respectively 1.5-, 4- and 19-fold). Under the influence of DNA_lig, TLR9 expression was 105-fold increased, whereas TLR3 expression was 2-fold higher, along with decrease of TLR2 expression. Expression of TLR 3 was shown to be 3-times higher under the influence of RNA_lig. The effects observed could be potentially applied for suppression of tumor cell chemotaxis by means of these ligands and by influencing different pathways of chemotaxis regulation.