Biology subjects

Kleymenov, D. A.

Publications and source records attributed to Kleymenov, D. A..

5 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

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↗

bioRxiv2023

Trivalent mRNA vaccine-candidate against seasonal flu with cross-specific humoral immune response

ABSTRACTSeasonal influenza remains a serious global health problem, leading to high mortality rates among the elderly and individuals with comorbidities. It also imposes a substantial economic burden through increased absenteeism during periods of active pathogen circulation. Vaccination is generally accepted as the most effective strategy for influenza prevention. As both influenza A and B viruses circulate and cause seasonal epidemics, vaccines need to include multiple antigens derived from different viral subtypes. While current influenza vaccines are effective, they still have limitations, including narrow specificity for certain serological variants, which may result in a mismatch between vaccine antigens and circulating strains. Additionally, the rapid variability of the virus poses challenges in providing extended protection beyond a single season. Therefore, mRNA technology is particularly promising for influenza prevention, as it enables the rapid development of multivalent vaccines and allows for quick updates of their antigenic composition. mRNA vaccines have already proven successful in preventing COVID-19 by eliciting rapid cellular and humoral immune responses. In this study, we present the development of a trivalent mRNA vaccine candidates, evaluate its immunogenicity using the hemagglutination inhibition assay, and assess its efficacy in animals. We demonstrate the higher immunogenicity of the mRNA vaccine candidates compared to the inactivated split influenza vaccine and its enhanced ability to generate a cross-specific humoral immune response. These findings highlight the potential mRNA technology in overcoming current limitations of influenza vaccines and hold promise for ensuring greater efficacy in preventing seasonal influenza outbreaks.

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↗