Immunomodulators: myths and reality
Medicines and substances intended for selective action on various parts of the immune system in order to prevent and treat infectious and some non-infectious diseases are considered. Special attention is placed to up-to-date requirements of evidence-based medicine. Examples of creation, development, production and implementation of modern immunotropic medicines are given. Promising strategies of applying technologies for creating and using immunotropic drugs that activate innate and adaptive immunity in medical practice are discussed.
Epithelial cells of the respiratory tract as equal participants of innate immunity and potential targets for immunotropic drugs
A new viewpoint of respiratory epithelial cells as an important part of innate immunity is considered in the review. Due to the fact that epithelial cells of the respiratory tract mucosa are the first line of defense that prevents the penetration of microbes into the internal environment of the body, the data presented are important in the context of fighting viral and bacterial infections by epithelial cells activation. Special attention is devoted to the receptors and signaling proteins of epithelial cells. The analysis of the respiratory epithelial cells’ role as an important component of the innate immune response arises the question of creating and developing approaches that can increase the functional activity of epithelial cells. In conclusion, the possibility of using medicines based on muramyldipeptides (MDP) and, in particular, GMDP, for the prevention and treatment of viral and bacterial infections of the respiratory, gastrointestinal and urogenital tracts is considered.
The role of NF-κB in the synergistic response of human macrophages to combined stimulation of NOD1 and TLR4 receptors in vitro
Introduction. Stimulation of macrophages by a combination of NOD1 and TLR4 receptor agonists results in a synergistic enhancement of cytokine expression: cellular response to the combination of agonist is greater than the sum of responses to each individual agonist. A central role in NOD1- and TLR4-dependent cytokine expression belongs to the NF-κB family of transcription factors.
Aims - to investigate the mode of activation of NF-κB-dependent signaling pathway in macrophages upon their treatment with a combination of NOD1 and TLR4 agonists, to compare kinetics of NF-κB pathway activation with kinetics of TNF and IL6 mRNA expression.
Material and methods. Macrophages were obtained from blood monocytes of healthy donors and stimulated with NOD1 agonist (N-acetyl-D-muramyl-L-alanyl-D-isoglutamyl-meso-diaminopimelic acid), TLR4 agonist (lipopolysaccharide) and their combination. TNF and IL6 mRNA were determined by reverse-transcription real-time PCR, levels of NF-kB proteins in the nucleus and of IκBα in the cytoplasm and in the nucleus by Western blotting.
Results. Translocation of NF-κB proteins (p65/RelA, c-Rel, p50) to the nucleus during the first 4 h of combined NOD1 and TLR4 stimulation is not synergistic. However, at the output of the nucleus, a synergistic enhancement of TNF and IL6 mRNA expression is observed after 150 minutes of combined receptor stimulation. We consider possible role of relative deficiency of nuclear IκBα in the development of the synergistic response. Conclusion. Synergistic enhancement of cytokine expression upon simultaneous NOD1 and TLR4 activation is not explained by synergistic activation of the NF-κB-dependent signaling pathway
Contradictory effect of recombinant interferon α2b on the non-transformed and transformed phenotypes of functionally significant subpopulations of neutrophilic granulocytes in vitro
Introduction. Modern studies demonstrate the multifunctionality of neutrophil granulocytes (NG) and indicate the presence of various NG subpopulations. Each of the NG subpopulations has its own phenotypic and functional features. NG subpopulations reveal plasticity and can change their phenotype under influences of the microenvironment, exerting both positive and negative (suppressing, damaging) effects on the course of the infectious and inflammatory process.
The aim of the study was to determine the possibility of experimental reprogramming of the transformed phenotype of functionally significant NG subpopulations in children with acute small purulent infection (SPI) under the influence of the substance of recombinant interferon α2b (rIFNα2b) in the in vitro system.
Material and methods. Samples of peripheral blood (PB) of 12 children of both sexes aged 2-4 years with acute small purulent infection (MGI) (the study group) and 7 conditionally healthy children, comparable in gender and age (the group of comparison), were studied. The number of NG subpopulations СD64-CD16+CD32+CD11b+, СD64+CD16+CD32+CD11b+, CD62L+СD63-, CD62L+СD63+ was determined by flow cytometry, with refinement of their phenotype by the expression density of each studied membrane molecule according to MFI. Phagocytic and microbicidal functions of NG were studied in children of the both groups. PB samples from children of the study group and the group of comparison were incubated in the in vitro system for 1 h at 370С with a rIFNα2b at a final concentration of 10-6 g/l, after which the features of transformation of the phenotype of NG subpopulations in both groups of children were monitored.
Results. Variants of negative transformation of phenotypes of functionally significant NG subpopulations were found: an increase in the number of activated CD62LdimCD63mid-NG, СD64dimCD16midCD32dimCD11bbright-NG against the background of a decrease in the level of the major subpopulation СD64-CD16midCD32dimCD11bbright and violations of phagocytic and microbicidal functions of NG. A subpopulation of СD64dimCD16midCD32dimCD11bbright-NG with inadequate pro-inflammatory properties was identified. It was shown the possibility of phenotype reprogramming of various NG subpopulations in study group with SPI under the influence of rIFNα2b, which contributed to the positive regulation of the functional cell activity.
Conclusion. Our study demonstrated negative transformation of the phenotype of functionally significant NG subpopulations in children with SPI. The immunomodulatory effects of rIFNα2b were shown on the negatively transformed NG phenotype in study group with the local purulent process. Those effects were manifested in the switch of NG phenotype from the pro-inflammatory to the anti-inflammatory one.
A heterologous virus-vectored vaccine for prevention of Middle East respiratory syndrome induces long protective immune response against MERS-CoV
Introduction. Middle East respiratory syndrome (MERS) is acute inflammatory disease of respiratory system with a high mortality, caused by coronavirus MERS-CoV. At present moment, we still lack specific therapeutic preparations and vaccines against MERS. Vaccine administration can help to limit the spread of the disease and lower the mortality. Duration of vaccine-induced immune response is one of the key characteristics of a vaccine, which is connected with duration of its protective effectiveness. Unfortunately, the data on duration of vaccine-induced immune response against MERS is scarce.
The aim of the study was to determine duration of humoral immune response in mice and primates and duration of protective immune response in mice after immunization with the heterologous virus-vectored vaccine against MERS (BVRS-GamVac-Combi), developed earlier by our research group.
Material and methods. To study duration of humoral immune response, we used mice of C57BL/6 strain and common marmosets. Animals were immunized with the vaccine BVRS-GamVac-Combi, based on recombinant adenoviral vectors rAd26 and rAd5. Antigen-specific-antibody titers were determined with ELISA, virus-neutralizing antibody titers were measured with virus neutralization assay using MERS-CoV (EMC/2012). To study duration of protective immune response, we used a model of lethal infection on transgenic mice, carrying human DPP4 gene of viral receptor.
Results. In present research, we showed that vaccination of animals with BVRS-GamVac-Combi induced robust humoral immune response, which persisted at least 18 months after immunization. In addition, our vaccine protected 100 % of animals from lethal infection for at least 7 months after immunization.
Conclusion. Strength of vaccine-induced immune response is generally connected with a protective effectiveness of a vaccine. One of the key problems of vaccine design is to find a way to provide as long and robust immune response as possible. Duration of vaccine-induced immune response is one of the key characteristics of a vaccine, which demands quality control during multiple steps of a vaccine development.
Alternative variants of interleukin-2 receptor alpha chain mRNA in colon cancer
Introduction. The alpha chain of the interleukin-2 receptor is encoded by a full-length mRNA which has several alternatively spliced variants whose function is unknown. Information on the occurrence of alternatives to mRNA alpha chain IL-2R in colon cancer help establish their role in antitumor immunity mechanisms.
The aim of the study was to detect the content of soluble CD25 molecules, a full-length form of IL-2Rα mRNA (CD25 mRNA) encoding a functionally active receptor alpha-chain and a form with 4 exon deletion (CD25Exo4Del mRNA) and 4 and 5 exons deletion (CD25Exo4-5Del mRNA) encoding a protein unable to bind interleukin-2. In the blood of healthy individuals and in the blood and tumors of colon cancer patients and compare the expression of IL-2Rα mRNA alternative forms with an expression of the genes coding CD38, ICAM-1, Fas and several cancer-testicular antigens (MAGEA1-MAGEA6, CT7 (MAGEC1), GAGE1-GAGE8, NY-ESO-1, SSX1, 2, 4, TRAG3 and XAGE1) expression.
Material and methods. 49 tumor samples and 10 peripheral blood samles of colon cancer are used in the work. The study was carried out by a reverse transcription polymerase chain reaction.
Results. It was shown that three alternative forms of mRNA IL-2Rα present in the blood of both healthy individuals and patients with colon cancer. In tumors, alternative mRNAs of IL-2Rα were detected with different frequencies. Full-length mRNA was detected most often, CD25Exo4Del mRNA - with an intermediate frequency and CD25Exo4-5Del mRNA - most rarely. There was a tendency to decrease the frequency of CD25Exo4-5Del mRNA detection in the late stages of the disease. ICAM-1 expression frequency in mRNA CD25Exo4-5Del negative tumors was increased, and soluble CD25 molecules serum level in the absence of CD25Exo4Del mRNA in tumor was also increased.
Сonclusion. The regulatory role of IL-2Rα mRNA deleted forms products leading to regulatory T cells activation, immunosuppression increasing and tumor growth progression was established.
Several features of inflammation at the patients with atopic bronchial asthma when exposed to respiratory viruses
The modern interpretation of the pathogenesis bronchial asthma (ВА) emphasizes the role of systemic inflammation at the BA, since its development under the influence of specific (allergens) and non-specific factors leads to an imbalance of pro- and anti-inflammatory cytokines in the airways. It has been established that most exacerbations of BA occur due to the influence of respiratory viral infection (RVI). The process of inflammation in the airways with virus-induced exacerbations of BA depends on the type of respiratory virus, and also phenotype and endotype of BA at the patient. Based on in vitro and in vivo studies, the role of interleukin-33 (IL-33) in the pathogenesis exacerbation of atopic BA in the mouse model is described.
The aim of our work is to determine the IL33 gene expression and study its role during development of atopic BA and its virus-induced exacerbation in humans.
Material and methods. All volunteers included in the study were divided into groups: «BA», «BA+RVI», «RVI», «healthy donors». All study participants underwent clinical, laboratory, instrumental (spirometry), allergological, immunological examination (determination the expression mRNA of the IL33 gene in peripheral venous blood and identification the mRNA of respiratory viruses (RSV, RV, coronaviruses, influenza virus type A and B, metapnevmovi-ruses, adenoviruses, bokaviruses, parainfluenza viruses type 1, 2, 3, 4) in smears from the nasal cavity by RT-PCR).
Results. In the «BA» and «BA+RVI» groups were observed the decrease FEV1, increased the ACQ-7 (more than 1.5 points), the blood eosinophilia (P = 0.000002), which characterizes the uncontrolled course and exacerbation of atopic BA from volunteers. The highest level of the expression mRNA IL-33 was found at the «BA+RVI» group (P = 0.003), and in the absence of RVI in volunteers with exacerbation of atopic BA the level of IL-33 not differs from healthy donors. According to the results of our study the more severe course of atopic BA was observed in the season with a predominance of RSV infection in 2017 compared to 2016 according to ACQ-7 (P = 0.00004 and P = 0.0002) and FEV1 (P = 0.006 and P = 0.008), respectively.
Conclusions. The results of the study provide additional evidence of the role of pro-inflammatory IL-33 in the pathogenesis of RVI and virus-induced exacerbations of atopic BA (most often RSV and RV). Identification of new mechanisms of virus-induced exacerbations of atopic BA can be used in the selection and development of personalized basic therapy of asthma.
Immunology of acute phase proteins of inflammation and work of R.V. Petrov
A review of the literature and achievements of the authors over 25 years in the study of acute phase inflammation proteins of the pentraxin family - C-reactive protein (CRP) and serum amyloid P component (SAP). The authors dedicate the review to Academician R.V. Petrov, a pioneer of immunology of inflammation research in Russia in honor of his 90th anniversary.
Glucosaminylmuramyldipeptide - GMDP: effect on mucosal immunity (on the issue of immunotherapy and immunoprophylaxis)
The analysis of the clinical application effectiveness of the drug Limpid® (the substance is glucosaminylmuramyldipeptide - GMDP), is discussed. Many years of experience using the drug Licopid® in diseases associated with the mucous layers of the body, forming the mucosal immunity system, has shown high efficiency in therapy and prevention. On the example of clinical application showing the systemic use of the drug Licopid® in ophthalmology, the treatment of respiratory diseases, including acute respiratory children and adults infections, tuberculosis; diseases of the gastrointestinal and urogenital tracts, it has been demonstrated that Licopid® is effective in the immunoprophylaxis of various diseases, prevents relapse of acute respiratory infections, bacterial and herpetic children and adults infections, and is effective in the treatment and prevention of seasonal and allergic diseases. The study of the mechanism of Licopid® action, a wide range activity and the side effects absence are the basis for recommendations on the widespread use of GMDP in medical practice, immunotherapy and immunoprophylaxis.