The development and application of therapeutic oligonucleotides, such as siRNA, miRNA, ASOs and aptamers, is a rapidly growing field in biomedicine. These molecules are undergoing extensive preclinical and clinical testing, and the market for synthetic RNA drugs is expanding. However, several challenges remain, including targeted delivery and high costs associated with development, screening and production. One significant advance has been the creation of GalNAc-conjugates, which selectively target ASGPR and deliver oligonucleotides to hepatocytes. Although these conjugates have shown promising results, their widespread use is limited by the lack of effective synthesis methods. Thus, the development of new methods for the synthesis of ligand-oligonucleotide conjugates is an important task to which this study is devoted. In this study, we created a library of siRNA conjugates with the GalNAc L-96 ligand to suppress the expression of the PCSK9 gene associated with elevated LDL and an increased risk of developing cardiovascular diseases. The selection of the most effective siRNA molecules was carried out using an algorithm previously developed by our research group, which considers thermodynamic stability, predicted specificity and effectiveness. To experimentally confirm the effectiveness of conjugates, an in vitro model based on the cultivation of hepatocyte cells was developed. Optimization of the conjugate synthesis process has significantly reduced the cost of manufacturing technology, which creates the potential for efficient scaling of synthesis for transfer and application in the pharmaceutical industry. The results of the study showed that the development of the siRNA sequence optimized in silico resulted in a significant increase in the inhibitory effect of the GalNAc-siRNA conjugate compared to a compound similar to a commercial drug.

Every year, the scientific community continues to drive advances in healthcare, opening up new perspectives in the treatment and management of various diseases. Despite vast strides being made in the quality of life and longevity, we still face an equally significant growth in the burden of oncological pathologies. Although current trends lean towards preventive and personalized medicine, numerous hurdles remain to be cleared to develop robust strategies in the field of oncology. Among all types of tumors, one of the prominent positions is occupied by hepatocellular carcinoma (HCC), which is one of the most widespread primary cancers with a high mortality rate. Conventional approaches to HCC therapy, such as surgery or chemotherapy, rarely provide steady performance due to the highly polymorphous nature of the cancerous process. In this study, we suggest an alternative methodological framework for designing potent siRNAs targeting genes implicated in hepatocellular carcinoma, implementing RNA interference mediated by synthetic small interfering RNAs (siRNAs) against mRNAs of ITGB1 and CD47 genes. Products of these genes are renowned drivers of tumor progression. We have developed a software algorithm for the design of unmodified and modified siRNAs, carried out solid-phase synthesis of the most promising molecules, and proved their capability to perform a more than 50-fold suppression of expression of the target genes in vitro.

Understanding T-cell receptor (TCR) specificity is not only essential for fundamental research, but could open up novel avenues for diagnostics, cancer immunotherapy, and the targeted treatment of autoimmune diseases. The immune system responds to challenges through groups of T-cells with similar TCR sequences. In recent years, searching for TCRs with an enrichment of similar sequences - neighbors - in a TCR repertoire has become a standard procedure for antigen-specific TCR identification. This study provides a systematic comparison of computational algorithms-ALICE, TCRNET, GLIPH2, and tcrdist3-that leverage neighborhood enrichment for antigen-specific TCR identification. Using published murine datasets from Lymphocytic choriomeningitis virus (LCMV) infection and novel datasets from Sputnik V vaccination and Mycobacterium tuberculosis (Mtb) infection, we evaluated the performance of these algorithms. To facilitate reproducible analysis, we developed TCRgrapher, an R library that integrates these pipelines into a user-friendly framework. TCRgrapher enables efficient identification of antigen-specific TCRs from single repertoire snapshots and supports flexible parameter customization. Our comparative analysis revealed that ALICE and TCRNET consistently outperformed GLIPH2 and tcrdist3 across most datasets, achieving higher area under precision-recall curve. While murine datasets provide valuable insights into algorithm performance, caution is advised when extrapolating these results to other species or different experimental conditions. TCRgrapher is freely available on GitHub (https://github.com/KseniaMIPT/tcrgrapher), offering researchers a robust tool for investigating TCR specificity and advancing immunological studies.

INTRODUCTION. Small interfering RNAs (siRNAs) are among the most promising types of therapeutic nucleic acids aiming at the inhibition of pathogenetically relevant gene expression through the RNA interference mechanism. However, the limited bioavailability and immunogenicity of siRNAs and imperfect delivery systems hinder the clinical potential and applicability of siRNA medicinal products.AIM. This study aimed to summarise recent advances in the development of siRNA medicinal products and the corresponding delivery systems, review clinical trial results, and outline future development prospects for these medicinal products.DISCUSSION. This article covers the molecular mechanisms underlying RNA interference, the considerations for siRNA development, and the techniques for effective siRNA delivery. The article dwells upon various systems for nucleic acid delivery to targeted cells. The most promising delivery systems are non-viral systems, including liposomes, exosomes, nanoparticles, polymers, cell-penetrating peptides, and GalNAc ligands. Their main advantages include their ease of complexation with nucleic acids, modification and functionalization potential, favourable safety profile, ability to cross biological barriers, and tropism to target tissues. The article summarises the information that has accumulated over the past few years in clinical trials of siRNA medicinal products for a range of conditions, including metabolic disorders, infections, and cancers, as well as hereditary, ophthalmic, renal, and hepatic diseases. Special attention is paid to siRNA medicinal products undergoing clinical trials (over 10 products) and approved for clinical use (6 products, including MIR 19, the first authorised Russian siRNA medicinal product).CONCLUSION. Ultimately, siRNA medicinal products are a promising tool for personalised medicine, exhibiting therapeutic potential for a wide range of pathological conditions. Further studies of siRNA medicinal products should aim at improving siRNA production technology to increase their bioavailability and half-life period. In addition, these studies should aim at enhancing delivery systems for these products to mitigate toxicity risks and maximise efficacy.

BACKGROUND Severe acute respiratory syndrome corona virus (SARS-CoV-2) infection frequently causes severe and prolonged disease but only few specific treatments are available. We aimed to investigate safety and efficacy of a SARS-CoV-2-specific siRNA-peptide dendrimer formulation (MIR 19 ®) targeting a conserved sequence in known SARS-CoV-2 variants for treatment of COVID-19. METHODS We conducted an open-label, randomized controlled multicenter phase II trial (NCT05184127) evaluating safety and efficacy of inhaled MIR 19 ® (3.7mg and 11.1 mg/day: groups 1 and 2, respectively) in comparison with standard etiotropic drug treatment (group 3) in patients hospitalized with moderate COVID-19. The primary endpoint was the time to clinical improvement according to predefined criteria within 14 days of randomization. RESULTS Patients from group1 had a significantly reduced (median 6 days (95% confidence interval [CI]: 5-7, HR 1.75, P=0.0005) time to clinical improvement compared to patients from group 3 (8 days (95% CI: 7-10). Normalized oxygen saturation (SpO >94%) occurred quicker in the group 1 (median 5 days (95% CI: 4–5, HR 1.59, P=0.0033) than in the group 3 (6 days, 95% CI: 5–8). Treatment with MIR 19® was well tolerated and safe. CONCLUSIONS MIR 19 ®, a SARS-CoV-2-specific siRNA-peptide dendrimer formulation is safe and significantly reduces time to clinical improvement in hospitalized moderate COVID-19 patients compared to standard therapy in a randomized controlled trial. MIR 19 ® treatment targets a sequence which is identical in all SARS-CoV-2 variants known so far and hence should be applicable for all of them.

Разработка и экспериментальная оценка аллергоида из пчелиного яда1 Федеральное государственное бюджетное учреждение «Государственный научный центр «Институт иммунологии» Федерального медико-биологического агентства

Since the beginning of the COVID-19 pandemic, the scientific community has focused on prophylactic vaccine development. In parallel, the experience of the pharmacotherapy of this disease has increased. Due to the declining protective capacity of vaccines against new strains, as well as increased knowledge about the structure and biology of the pathogen, control of the disease has shifted to the focus of antiviral drug development over the past year. Clinical data on safety and efficacy of antivirals acting at various stages of the virus life cycle has been published. In this review, we summarize mechanisms and clinical efficacy of antiviral therapy of COVID-19 with drugs based on plasma of convalescents, monoclonal antibodies, interferons, fusion inhibitors, nucleoside analogs, and protease inhibitors. The current status of the drugs described is also summarized in relation to the official clinical guidelines for the treatment of COVID-19. In addition, here we describe innovative drugs whose antiviral effect is provided by antisense oligonucleotides targeting the SARS-CoV-2 genome. Analysis of laboratory and clinical data suggests that current antivirals successfully combat broad spectra of emerging strains of SARS-CoV-2 providing reliable defense against COVID-19.

Аддитивный эффект синтетических малых интерферирующих РНК в отношении респираторно-синцитиального вируса 1 Федеральное государственное бюджетное учреждение «Государственный научный центр «Институт иммунологии» Федерального медико-биологического агентства, 115522, г.Москва, Российская Федерация 2 Федеральное государственное автономное образовательное учреждение высшего образования «Первый Московский государственный медицинский университет имени И.М.Сеченова» Министерства здравоохранения Российской Федерации (Сеченовский Университет), 119991, г.Москва, Российская Федерация 3 Федеральное государственное бюджетное научное учреждение «Научно-исследовательский институт вакцин и сывороток им.И.И

МИР 19 ® -первый в мире специфический противовирусный препарат для лечения COVID-19: разработка и доклинические исследования 1 Федеральное государственное бюджетное учреждение «Государственный научный центр «Институт иммунологии» Федерального медико-биологического агентства, 115522, г.Москва, Российская Федерация 2 Федеральное государственное автономное образовательное учр еждение высшего образования «Российский национальный исследовательский медицинский университет имени Н.И.Пирогова» Министерства здравоохранения Российской Федерации, 117997, г.Москва, Российская Федерация 3 Федеральное государственное бюджетное научное учреждение «Научно-исследовательский институт вакцин и сывороток им.И.И

Результаты I и II фазы клинических исследований препарата МИР 19 ® 1 Федеральное государственное бюджетное учреждение «Государственный научный центр «Институт иммунологии» Федерального медико-биологического агентства, 115522, г.Москва, Российская Федерация 2 Федеральное государственное автономное образовательное учреждение высшего образования «Российский национальный исследовательский медицинский университет имени Н.И.Пирогова» Министерства здравоохранения Российской Федерации, 117997, г.Москва, Российская Федерация 3 Федеральное государственное бюджетное научное учреждение «Научно-исследовательский институт вакцин и сывороток им.И.И.Мечникова» Министерства науки и высшего образования Российской Федерации, 105064, г.Москва, Российская Федерация 4 Федеральное государственное автономное образовательное учреждение высшего образования «Первый Московский государственный медицинский университет имени И.М

The vast majority of SARS-CoV-2 vaccines which are licensed or under development focus on the spike (S) protein and its receptor binding domain (RBD). However, the S protein shows considerable sequence variations among variants of concern. The aim of this study was to develop and characterize a SARS-CoV-2 vaccine targeting the highly conserved nucleocapsid (N) protein. Recombinant N protein was expressed in Escherichia coli, purified to homogeneity by chromatography and characterized by SDS-PAGE, immunoblotting, mass spectrometry, dynamic light scattering and differential scanning calorimetry. The vaccine, formulated as a squalane-based emulsion, was used to immunize Balb/c mice and NOD SCID gamma (NSG) mice engrafted with human PBMCs, rabbits and marmoset monkeys. Safety and immunogenicity of the vaccine was assessed via ELISA, cytokine titer assays and CFSE dilution assays. The protective effect of the vaccine was studied in SARS-CoV-2-infected Syrian hamsters. Immunization induced sustainable N-specific IgG responses and an N-specific mixed Th1/Th2 cytokine response. In marmoset monkeys, an N-specific CD4+/CD8+ T cell response was observed. Vaccinated Syrian hamsters showed reduced lung histopathology, lower virus proliferation, lower lung weight relative to the body, and faster body weight recovery. Convacell® thus is shown to be effective and may augment the existing armamentarium of vaccines against COVID-19.

Introduction. Despite widespread vaccination against COVID-19 worldwide, the epidemiological situation remains insufficient. The appearance of mutant forms of SARS-CoV-2 with increased virulence causes new waves of COVID-19 morbidity. The virus variability can cause the reduction of the vaccination effectiveness. In this regard, it is important to study the dynamics of post-vaccination immunity, its features in various population groups, as well as the relationship between post-infectious and post-vaccination immunity. The study continues a series of researches of the features of SARS-CoV-2-specific immunity in COVID-19 convalescents and recipients of the <> vaccine. The aim of the study - assessment of the intensity of the SARS-CoV-2-specific immune response in different age groups of people passed COVID-19 and subsequently vaccinated with <>. Material and methods. With the help of EIA, the level of IgG antibodies to S-antigen and N-antigen of SARS-CoV-2 was studied in 155 samples of blood sera of individuals (men and women) aged 18 to 70 years who passed COVID-19 and after 6 month of recovery underwent a full course of vaccination with <>. Samples from individuals of the following age groups were examined: from 18 to 35, from 35 to 45, from 45 to 55, from 55 to 65, from 65 to 70 years. Results. In all the examined age groups of individuals passed COVID-19 and then vaccinated with <>, there was a high level of IgG antibodies to SARS-CoV-2 S-protein (positivity coefficient 8.1 and higher). The level of IgG antibodies to the N-protein in more than half of the cases was lower than positive values among all the subjects. Conclusion. The study showed that individuals passed COVID-19 and then vaccinated with <>, regardless of age, have intense post-vaccination humoral immunity. Copyright © 2022 Meditsina Publishers. All rights reserved.

One of the greatest medical advances of the last century has been the introduction of organ transplantation. However, despite the considerable potential of transplantation as often the only therapy for severe diseases, the toxicity of immunosuppressive drugs supporting the transplant remains a serious problem for its further development. Modification of immune response in order to form tolerance to the transplanted organ can play an important role on the way to minimize immunosuppression. Successful cases of withdrawal of immunosuppressive drugs for medical reasons in kidney and liver transplantation recorded in the literature, as well as the results obtained in the process of modeling such a situation in the experiment, prove that achieving tolerance in organ transplantation is fundamentally possible. The aim of this review is to investigate the ways of immunologic suppression and fundamental mechanisms of immunologic tolerance in the field of transplantation and to review the latest clinical achievements in this respect. The review describes various approaches to the induction of central tolerance in solid organ transplantation implemented in the framework of the original clinical protocols. Special attention is given to a new direction in transplantation medicine – cell technologies providing tolerogenic effect by means of peripheral mechanisms activation, in particular due to activation of suppressor function of regulatory T cells. We draw the attention to the advantages and disadvantages of these two trends. Which of them is preferable? In which direction will scientific thought be developed for realization of the long-term goal of transplantologists: to avoid allograft rejection without affecting the physiological homeostasis of the body? Possible answers to these questions are discussed in this review.

Abstract BACKGROUND AND AIMS Due to the increasing need for kidney transplantation, there is a demand for new methods of preventing rejection of the transplant based on the mechanisms of natural regulation of the immune response. Extracorporeal photopheresis (ECP) is one of these technologies whose clinical efficacy in the prevention and treatment of acute renal transplant rejection has been confirmed by many studies, but the mechanism of its effect has not been fully understood. Characterization of the genes responsible for the activation and inhibition of the immune response during ECP is an important step towards the modification of immunosuppressive therapy. The aim of this study was to analyze the changes in the expression level of the genes responsible for the activation and inhibition of the T-cell response in the recipients of the renal graft after ECP. METHOD An open cohort randomized trial was conducted with 20 patients who underwent a single group cadaver kidney transplantation from an unrelated donor. The recipients of the compared groups received standard immunosuppressive therapy and the same therapy in combination with ECP procedures, according to the study protocol. Each recipient of the main group received 15 sessions of ECP within 6 months. The level of gene expression was analyzed by real-time RT-PCR. Comparison of the study groups was carried out at point 1 (1st–4th day) and 2 (30th day). RESULTS The analysis of clinical data did not show statistically significant clinical differences, but in the specific consideration of each pair of cases, the tendency to some improvement in the transplant organ engraftment rate in the early terms after the transplant, and better survival of the graft and the recipient was revealed. For instance, patients of the main group revealed no transplant rejection by clinical laboratory signs as well as the results of histological examination of biopsy specimens. In the comparison group, acute graft rejection was clinically diagnosed and was confirmed by histological examination as humoral type rejection. The level of expression of genes involved in immune response regulation (CD28, CTLA4, PDL1 and FOXP3) and cytokine genes (TNFA, IL1, IL2, IL10 and IFNG) in the studied groups was determined. A decrease in the level of expression of the genes for the proinflammatory cytokines IL1, IL2 and IFNG was noted by the 30th day after transplantation. At the same time, the expression of the genes PDL1 and FOXP3, which regulate the development of the regulatory response, significantly increased by the 30th day after transplantation. Correlations of the level of gene expression with the presence/absence of rejection episodes have not been established. To assess the effect of the ECP on these gene expression, a comparison was made of the level sof transcript representation of patients receiving standard immunotherapy and immunotherapy in combination with ECP, and a significant increase in the expression of PDL1 and FOXP3 genes (Fig. 1A and B) was found in the group of patients who underwent ECP procedures (P = .0009 and .0013, respectively). CONCLUSION According to the results of comparative analysis, the level of expression of pro-inflammatory cytokines' genes IL1, IL2 and IFNG decreased to the 30th day after transplantation. A 30-day comparison between groups shows an increase in the expression level of the PDL1 and FOXP3 genes. Increased expression of these genes may be associated with the activation of regulatory T-cells and the development of peripheral tolerance and can become a criterion for the modification of immunosuppressive therapy.

In this population-based case-control study conducted in the Chelyabinsk region of Russia, we examined the distribution of HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1, in a group of 100 patients with confirmed COVID-19 bilateral pneumonia. Typing was performed by NGS and statistical calculations were carried out with the Arlequin program. HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 alleles were compared between patients with COVID-19 and 99 healthy controls. We identified that COVID-19 susceptibility is associated with alleles and genotypes rs9277534A (disequilibrium with HLA-DPB1*02:01, -02:02, -04:01, -04:02, -17:01 alleles) with low expression of protein products HLA-DPB1 (pc < 0.028) and homozygosity at HLA-C*04 (p = 0.024, pc = 0.312). Allele HLA-A*01:01 was decreased in a group of patients with severe forms of bilateral pneumonia, and therefore it may be considered as a protective factor for the development of severe symptoms of COVID-19 (p = 0.009, pc = 0.225). Our studies provide further evidence for the functional association between HLA genes and COVID-19.