Biology subjects

Logunov, D. Y.

Publications and source records attributed to Logunov, D. Y..

6 recordsLinked to original sources

bioRxiv2025

Circular mRNA against Clean Cap linear mRNA vectors comprehensive comparison, expression, active and passive immunization

The mRNA platform has revolutionised vaccine technology by providing a universal, fast and easily scalable production process. There are two main types of mRNA - linear (cap-dependent) and circular (cap-independent), each with its own advantages. Although both vector types are continuously being improved, there has been no comprehensive comparative analysis of the most efficient existing vectors of each type. This paper provides a comparison of expression efficiency, protective and therapeutic activities of circular and linear mRNA vectors. We examined different combinations of linear vectors: containing either N1-methylpseudouridines or uridine and capped with either ARCA (m7G(5')ppp(5')G) or CleanCap (m7G(5')ppp(5')m2G). Circular vectors contained both commonly used IRES of coxsackievirus B3 and new a IRES of human rhinoviruses B6. Preliminary luciferase assay showed that modified linear vectors exhibited significantly higher expression levels both in vitro and in vivo. A similar but less dramatic difference was observed in expression of the target protein. At the same time, immunogenicity and protective activity of linear and circular vectors were equal.

immunology↗

bioRxiv2025

Comparison candidate Tick-borne encephalitis virus vaccines based on mRNA, adenovirus serotype 25 and chimera of YFV vaccine strain

BackgroundDespite the availability of several licensed inactivated vaccines, the development of new vaccines against the Tick-borne encephalitis virus (TBEV) remains an important task, especially in countries endemic to this pathogen. The risk of infection with TBEV increases every year because of increase in the number of ticks, the emergence of tick carriers into new territories, and active human activity in areas of TBEV natural foci. Annual reports of vaccination failures have prompted us to search for approaches to creating a new vaccine. ObjectivesIn our study, we used the same PrM and E antigens to produce three vaccine candidates against tick-borne encephalitis (TBE): 1) a live attenuated YFV 17DD-UN vaccine strain, 2) recombinant adenovirus (rAd) vectors, and 3) mRNA encapsulated in lipid nanoparticles (LNP). MethodsWe generated and assessed the immunogenicity and protective efficacy of three candidate TBEV vaccines based on mRNA, simian adenovirus type 25, and a chimera of the YFV 17DD-UN attenuated strain. ResultsAnalysis of the virus-neutralizing titers in the blood sera of immunized mice revealed a statistically significant difference among the three candidate vaccines. The immunogenicity and protective efficacy of the candidate mRNA-LNP vaccine were found to be higher than those of the other two vaccines. ConclusionsBased on the results of our study, it can be concluded that the mRNA-based platform is more promising for the creation of a vaccine against TBEV.

immunology↗

bioRxiv2024

Seroprevalence and cross-reactivity of neutralizing antibodies to six types of adenoviruses

BackgroundThe use of adenoviral vector vaccines is an effective way to induce an antiviral immune response. Most vaccines used worldwide are based on human adenovirus type 5 (Ad5). Pre-existing natural immunity to Ad5 is a limitation to the frequent use of Ad5-based vectors in gene therapy and vaccination. In the present study, we assessed the seroprevalence and cross-reactivity of neutralizing antibodies to six adenovirus types: Ad1, Ad2, Ad5, Ad19, Ad26, and Ad37. MethodsThe study used immunological and virological research methods. Adenovirus vectors encoding the enhanced green fluorescent protein (EGFP) were developed by the N.F. Gamaleya National Research Center for Epidemiology and Microbiology. For seroprevalence and cross-neutralation study we used a panel of sera from 101 volunteers. ResultsThe conducted correlation analysis showed a strong relationship between seropositivity and the geometric mean titer of neutralizing antibodies to adenovirus. An increase in antibody titers indicates the formation of a humoral immune response and population immunity. We determined that there is no cross-reactivity between NtAbs to Ad1, Ad2, Ad5 and Ad26. ConclusionsBased on the presented data, we assume that Ad1 or Ad2 should be considered the most promising alternative candidates for the development of vaccine vectors.

immunology↗

bioRxiv2024

Major role of S-glycoprotein in providing immunogenicity and protective immunity in mRNA lipid nanoparticle vaccines based on SARS-CoV-2 structural proteins

Recently we have developed an mRNA lipid nanoparticle (mRNA-LNP) platform providing efficient long-term expression of an encoded gene in vivo after both intramuscular and intravenous application. Based on this platform, we have generated mRNA-LNP coding SARS-CoV-2 structural proteins M, N, S from different virus variants and studied their immunogenicity separately or in combinations in vivo. As a result, all candidate vaccine compositions coding S and N proteins induced excellent anti-RBD and N titers of binding antibodies. T cell responses mainly represented specific CD4+ T cell lymphocyte producing IL-2 and TNF-. mRNA-LNP coding M protein did not show high immunogenicity. High neutralizing activity was detected in sera of mice vaccinated with mRNA-LNP coding S protein (alone or in combinations) against closely related strains but was not detectable or significantly lower against an evolutionarily distant variant. Our data showed that the addition of mRNAs encoding S and M antigens to the mRNA-N in the vaccine composition enhanced immunogenicity of mRNA-N inducing more robust immune response to the N protein. Based on our results, we suggested that the S protein plays a key role in enhancement of immune response to the N protein in the mRNA-LNP vaccine.

immunology↗

bioRxiv2022

Single-domain antibody delivery using an mRNA platform protects against lethal doses of botulinum neurotoxin A

Single-domain antibodies (sdAbs, VHHs, or nanobodies) are a promising tool for the treatment of both infectious and somatic diseases. Their small size greatly simplifies any genetic engineering manipulations. Such antibodies have the ability to bind hard-to-reach antigenic epitopes through long parts of the variable chains, the third complementarity-determining regions (CDR3s). VHH fusion with the canonical immunoglobulin Fc fragment allows the Fc-fusion single-domain antibodies (VHH-Fc) to significantly increase their neutralizing activity and serum half-life. Previously we have developed and characterized VHH-Fc specific to botulinum neurotoxin A (BoNT/A), that showed a 1000-fold higher protective activity than monomeric form when challenged with five times the lethal dose (5 LD50) of BoNT/A. During the COVID-19 pandemic, mRNA vaccines based on lipid nanoparticles (LNP) as a delivery system have become an important translational technology that has significantly accelerated the clinical introduction of mRNA platforms. We have developed an mRNA platform that provides long-term expression after both intramuscular and intravenous application. The platform has been extensively characterized using firefly luciferase (Fluc) as a reporter. An intramuscular administration of LNP-mRNA encoding VHH-Fc antibody made it possible to achieve its rapid expression in mice and resulted in 100% protection when challenged with up to 100 LD50 of BoNT/A. The presented approach for the delivery of sdAbs using mRNA technology greatly simplifies drug development for antibody therapy and can be used for emergency prophylaxis.

molecular biology↗

bioRxiv2021

Single-domain antibodies efficiently neutralize SARS-CoV-2 variants of concern

Virus-neutralizing antibodies are one of the few treatment options for COVID-19. The evolution of SARS-CoV-2 virus has led to the emergence of virus variants with reduced sensitivity to some antibody-based therapies. The development of potent antibodies with a broad spectrum of neutralizing activity is urgently needed. Here we isolated a panel of single-domain antibodies that specifically bind to the receptor-binding domain of SARS-CoV-2 S glycoprotein. Three of the selected antibodies exhibiting most robust neutralization potency were used to generate dimeric molecules. We observed that these modifications resulted in up to a 200-fold increase in neutralizing activity. The most potent heterodimeric molecule efficiently neutralized each of SARS-CoV-2 variant of concern, including Alpha, Beta, Gamma, Delta and Omicron variants. This heterodimeric molecule could be a promising drug candidate for a treatment for COVID-19 caused by virus variants of concern.

immunology↗