Molecular immunological aspects of diagnostics, prevention and treatment of coronavirus infection
The rapid spread of the infection caused by the new coronavirus SARS-CoV-2, which in a short time covered almost the whole world and acquired the pandemic character, has become a serious challenge to the health care system. Unprecedented measures are being taken to organize medical care for infected people, carry out quarantine measures, develop drugs for treatment and prevention of infection. Over the past 2020 year a significant amount of scientific information has been accumulated about the pathogenesis of SARS-CoV-2 infection, the biology of the virus and its interaction with the human immune system. This made it possible to come close to the development of effective substances of countering the spread of a new coronavirus infection - the development of effective vaccines and innovative targeted antiviral drugs. This review is devoted to analysis of the latest advances in the diagnosis, immunoprophylactics and treatment of COVID-19, a disease caused by the novel SARS-CoV-2 coronavirus.
Analysis of IL1B (rs1143627) IL4 (rs2243250), IL6 (rs1800795), IL8 (rs4073), IL10 (rs1800896, rs1800872), IL17A (rs227593) cytokines genes polymorphism and its complex genotypes among Caucasian patients of Western Siberia with primary open-angle glaucoma
Introduction. The significance of the relationship between cytokine genes polymorphism and the development of various forms of glaucoma has recently become one of the significant research topics.
Aim of the study - the analysis of promoter polymorphism of cytokine genes IL1B (rs1143627), IL4 (rs2243250), IL6 (rs1800795), IL8 (rs4073), IL10 (rs1800896), IL10 (rs1800872), IL17A (rs227593) and its complex in a group of patients with primary open-angle glaucoma (POAG) relatively healthy individuals to identify the association with the disease.
Material and methods. 99 patients with stage II POAG were examined. The comparison group included 100 people. Single-nucleotide polymorphism was studied by Real-Time PCR with SYBR Green I. Significance of differences in alternative groups was determined using 2-sided Fisher’s exact test with Bonferroni correction.
Results. IL1B-31*CC minor genotype, IL8-251*TT wild type genotype and IL8-251* TT:IL17-197*AA complex genotype are decrease in patients. Frequency distribution differences of positively and negatively associated genotypes with pathology in groups of men and women were revealed.
Conclusion. The analysis made it possible to identify the features of the frequency distribution of the genotypes of the studied genes associated with the development of the disease.
Changes in the expression of Toll-like receptors, cytokines and chemokines in the cells of the mucous membrane of the oropharynx in children with COVID-19
Introduction. COVID-19 is a severe respiratory disease caused by the β-coronavirus SARS-CoV-2, which is characterized by immune-mediated tissue and organ damage. It has been proven that the disease in children is relatively easy compared to adults, and the mechanisms of innate immunity play an important role in this.
The aim of the investigation was to study the expression of genes encoding the innate immunity receptors TLR4, TLR7, as well as to analyze changes in the expression of proinflammatory cytokines - interleukin(IL)-1β, tumor necrosis factor (TNF)-α and interferon (IFN)-α - in children with COVID-19, depending on the severity of the disease.
Material and methods. The study included 55 children with a confirmed diagnosis of COVID-19. Patient groups were formed on the basis of complaints and clinical manifestations. The 1st group of asymptomatic children included 9 people. The 2nd group included children were with a mild form of the course - 36 people, the 3rd group consisted of children with a moderate form of the course (10 people). The group of comparison consisted of 25 healthy children. RNA was isolated from the obtained material and the level of gene expression was determined by polymerase chain reaction in real time, and the level of cytokines in the supernatant was determined by the method of multiplex immunofluorescence analysis.
Results. A statistically significant increase in the expression of genes for innate immunity receptors (TLR4, TLR7) in the cells of the mucous membrane of the oropharynx in children with COVID-19 has been shown. The expression of TLR4 and TLR7 was, respectively, 2.6 and 7.2 times higher in children with moderate course compared with the healthy group. At the same time, an increase in the level of expression of pro-inflammatory cytokines (IL-1β, TNFα, IFN-α) at the gene and protein levels, associated with the severity of COVID-19 was revealed. Our study also showed an increase in the production of chemokines, which correlated with the severity of the disease.
Discussion. An increase in the expression level of the TLR4 and TLR7 genes by oropharyngeal mucosa cells in children with COVID-19 indicates their role in the pathogenesis of the disease. The main function of TLR4 and TLR7 is to recognize pathogen-associated molecular patterns, namely, the spike glycoprotein involved in the penetration of the virus into target cells and the single-stranded RNA of the virus. Activation of TLR4 and TLR7 leads to Toll-induced expression of genes for proinflammatory cytokines (IL-1β, TNFα, IFN-α) and chemokines, a significant increase in gene expression and protein production of which we have demonstrated. This plays a huge role in the development of the inflammatory response and indicates changes in the innate immunity of the mucous membranes in COVID-19.
Conclusion. The data obtained by us can be used for further study and determination of molecular genetic markers associated with COVID-19 in children, which will allow us to select the optimal therapy option in the future.
Toxin neutralizing activity of monoclonal antibodies against Bacillus anthracis lethal toxin
Introduction. Anthrax is an infection caused by a Gram-positive, spore-forming bacteria Bacillus anthracis. It is difficult to diagnose the early stages of disease at the gastrointestinal or pulmonary forms, and in the later stages antibiotic therapy becomes ineffective since the pathogenesis and outcome of the disease are determined by anthrax toxins. The lethal toxin plays the leading role in the death of the patients. One way to neutralize anthrax toxin is to use monoclonal antibodies specific to the lethal toxin (LT) subunits: protective antigen (PA) or lethal factor (LF).
Aim of the study - to characterize and evaluate the toxin neutralizing activity of monoclonal antibodies (MAbs) against the lethal toxin of B. anthracis in vitro and in vivo.
Material and methods. MAbs 1D6F10, 4F6F8, 9D5C9 and 1E10 specific to PA were obtained and were generated in vivo in ascitic fluid. The immunoglobulin fraction from ascitic fluid was isolated by affinity chromatography on a column with Protein G Sepharose sorbent. The domain specificity and subclass of MAbs were determined. To identify the most promising toxin neutralizing MAbs we performed in vivo and in vitro experiments: on laboratory BALb/c mice and on murine macrophage cell line J774A.1, respectively. Cell viability in vitro was assessed using the MTT-test.
Results. As a result of the made experiments the most promising MAb 1E10 was chosen from all panel of obtained MAbs. MAb 1E10 interacts with IV domain of PA. It was shown that MAb 1E10 in concentration from 1 pg/ml and above in an experiment in vitro with murine macrophage cell line J774A.1 neutralizes LT of B. anthracis. It was found that MAb 1Е10 at a dose of 100 pg/mouse protects 100 % of animal from death upon subsequent administration of 4LD50 LT in an experiments in vivo with BALB/c mice. MAb 1E10 is perspective for receiving on its basis of chimeric MAbs with reduced immunogenicity for human.
Conclusion. It can be assumed that MAb 1Е10 inhibits the 1st stage of LT assembly -the interaction of PA with surface receptors of eukaryotic cells, and thus can have a toxin neutralizing effect.
Possible role of anti-IL17 drugs in the management of COVID-19: our own experience and literature review
Coronavirus infection COVID-19 is an acute respiratory viral disease caused by a novel beta-coronavirus SARS-CoV-2. In 81 % of cases, mortality in COVID-19 patients is associated with the development of acute respiratory distress syndrome (ARDS). Another critical challenge associated with COVID-19 is the development of a cytokine storm, which is an uncontrolled release of proinflammatory mediators due to the excessive activation of immune system. Cytokine storm is another cause of high mortality because of COVID-19, as it leads to multiple organ failure, ARDS and disseminated intravascular coagulation (DIC). Thus, the management of cytokine storm and ARDS in COVID-19 patients is an urgent issue for the medical society. Recent research assessed the potential role of interleukin(IL)-17 in the pathogenesis of cytokine storm and ARDS in COVID-19 patients. Some authors also pointed to using anti-IL17 medications in the management of patients with severe COVID-19. The present article gives a literature review on the possible role of IL-17 in COVID-19 pathogenesis and our personal experience of anti-IL17 prescription for patients with severe course of COVID-19.
COVID-19 in children with bronchial asthma: clinical manifestations, course options, approaches to therapy
Introduction. Bronchial asthma (BA) is one of the most common chronic lung diseases in children. At the beginning of the COVID-19 pandemic, BA, like other lung diseases, was considered a risk factor for the severe course of COVID-19.
Aim of the study - to analyze the main clinical manifestations of COVID-19 in children with BA.
Material and methods. During 2020, 500 children with BA from the pulmonary department of the Sechenov University Children’s hospital were questioned. 3 % of them (15 children) were with COVID-19. Moreover, clinical picture of COVID-19 was analyzed in other 75 children with BA and 53 children without BA, who were observed in outpatient department and in Moscow pulmonary sanatorium N 15.
Results. It has been shown that the symptoms of COVID-19 can be similar to those of an exacerbation of asthma and manifest itself as dry cough and shortness of breath, and fever, which can also be observed with exacerbations of asthma against the background of a respiratory infection of any genesis.
Conclusion. Based on the factual clinical material, it was shown that the new coronavirus infection is easier in children, and in asthmatics among patients with less pronounced clinical symptoms.
Some subpopulations of lymphocytes in individuals exposed to ionizing radiation in utero
Introduction. It is known that during the period of intrauterine development, the developing organism is especially sensitive to adverse influences. Radiation-mediated immunological disorders play an important role in the formation of not only the early, but also the long-term consequences of radiation. Allergic and autoimmune syndromes predominated in the structure of immune deficiency syndromes. The state of immunity has been studied most fully in persons living in the Techa river basin and exposed to chronic radiation exposure as a result of discharges of liquid radioactive waste from the Mayak Production Association. In the longterm follow-up period, various disorders of innate and adaptive immunity were recorded in this group of individuals.
The aim of this study is to assess the subpopulation composition of lymphocytes in individuals exposed to intrauterine irradiation in the long term after irradiation.
Material and methods. In this work, the main subpopulations of lymphocytes were analyzed. The number of examined individuals was 56: 29 individuals in utero exposed to ionizing radiation (23 women and 6 men) and controls (25 women and 2 men). The age of the surveyed was from 52 to 72 years. Main lymphocyte subpopulations were measured using flow cytofluorimetry.
Results. There were no deviations in the absolute and relative content of lymphocyte subpopulations. There was a tendency towards a decrease in the number of lymphocytes expressing the marker of early activation CD25 with an increase in the total dose of external γ-irradiation of the mother during pregnancy.
Discussion. The obtained data on the subpopulation composition of lymphocytes are consistent with the results of a survey of persons living in the Techa river basin and exposed to intrauterine irradiation because of discharges of liquid radioactive waste from the Mayak Production Association, during which no changes in the subpopulation composition of lymphocytes were detected in prenatally irradiated persons. The revealed tendency towards a decrease in the relative number of lymphocytes expressing the marker of early activation of CD25 in persons exposed to intrauterine irradiation with an increase in the total absorbed dose of external γ-radiation in the bone marrow during the mother’s pregnancy is consistent with the results of experimental studies.
Conclusion. As a result of the study of persons exposed to intrauterine irradiation, no abnormalities were found in the main subpopulations of lymphocytes. A tendency towards a decrease in the relative number of lymphocytes expressing the marker of early activation of CD25 in persons exposed to intrauterine irradiation with an increase in the total absorbed dose of external γ-radiation during the mother’s pregnancy was found.
The role of factors of innate immunity in the formation of adaptation to stress
Introduction. Changes in the cellular factors of the innate immune system in the adaptation processes under stress have not been fully studied and the data on them are contradictory.
Aim of the study - research of the dynamic changes of cellular factors of innate immunity in military personnel under conditions of professional stress.
Material and methods. 37 servicemen (average age 37.3 ± 4.8 years) who participated in special operations (service in zones with an unfavorable operational situation lasting 3 months) were examined. The analysis of the cellular factors of the innate immune response was carried out before participating in special operations, immediately after returning from a zone with an unfavorable operational environment, and also after 3, 6, 12 months of observation.
Results. During dynamic observation of innate immunity parameters of military personnel participating in special operations, a weakening of the protective cytolitic activity of CD16+-cells was documented. A persistent inhibition of the processes of recognition and presentation of antigens at the level of TLR receptors of the monocytic link of the immune system was revealed.
Conclusion. Changes in the quantitative and functional parameters of cellular factors of innate immunity retained their significance in servicemen for a year after performing military duties in a zone with a difficult operational environment, which indicated the formation of persistent violations of the physiological adaptation process in the immune surveillance system.
Receptors of specialized pro-resolving mediators - a probable target of pharmacological restoration of homeostasis in allergic inflammation
The action of most of the existing antiallergic methods and means is aimed at eliminating the cellular and molecular participants in allergic inflammation, in addition to the pro-allergic ones, performing various important homeostatic functions in the body. The few exceptions are 2. First, allergen-specific immunotherapy (ASIT), which switches the allergic response, designed to recognize low doses of an allergen entering the body in case of insufficiency of barrier tissues, to a different type of immune response, designed to recognize high doses of antigen (allergen), but without damage the participants in allergic inflammation themselves. Secondly, the replenishment of the impaired function of histohematic barriers, which also did not affect the participants in the pathogenesis of allergy, but excludes the need for the allergic response itself. In recent decades, attention has been paid to the study of the mechanisms of resolution of inflammation and its allergic form, in particular. The concept of resolution of inflammation as an active process has become recognized, in which various anti-inflammatory mediators and lipid mediators (specialized pro-resolving mediators, SPMs) specialized for resolution are involved. Violation of the mechanisms for resolving allergic inflammation leads to an aggravation of its course, transition to a chronic state, tissue remodeling and the development of secondary pathology. This justified extensive studies aimed at restoring the resolution mechanisms without affecting the morphofunctional elements important for homeostasis. A promising direction of these studies is the use of SPMs receptors as targets for effects that restore homeostatic functions. The paper considers the existing information on the types of SPMs receptors and justified ways of their targeted use for pharmacologically induced resolution of allergic inflammation. These studies will create a third, fundamentally new approach to controlling allergic inflammation without damaging the participants in maintaining homeostasis.
The proteins of γ-globulin fraction, that bind metal ions, in physiological immune regulation. Opposite effects of copper and zinc
The data summarized in the paper concerning possibility of metal ions chelation by proteins of human γ-globulin blood plasma fraction from their periglobular space and of conformational changes dealing with such a binding in normal physiological conditions that primarily cause the shifts in Fc-fragment structures. As a result of such shifts dynamics of interactions of γ-globulins with Fc-receptors (FcR) expressed on the surface of immune system cells does change, and intracell signaling caused by FcR activation as well as cell responses induced by signal transduction from FcR do also shift. Copper and zinc ions bound by γ-globulin fraction proteins and localized within antibodies molecules by specifically distributed by their topics binding sites cause opposite changes of effector properties of γ-globulins that reciprocally shift cell functions in response to FcR activation by the proteins transformed with metal binding. In physiological immune regulation the proteins of γ-globulin fraction chelating the single copper and zinc ions and exerting thereby opposite effector properties support induction of cellular immunity simultaneously excluding the tolerance burst and pathological reactions towards own normal human cells.