Biology subjects

Blagodatskikh, K. A.

Publications and source records attributed to Blagodatskikh, K. A..

5 recordsLinked to original sources

bioRxiv2025

Strand Displacement Chain Reaction (SDCR): New Hybrid Amplification Technique for Fast and Sensitive Detection of Genetic Materials

Nucleic acid amplification methods are widely used in science, medicine and forensics for molecular biological assays and for the detection of genetic material. The newly developed strand displacement chain reaction (SDCR) method is a hybrid amplification technique based on polymerase chain reaction (PCR) and isothermal nucleic acid amplification. Here, we compared conventional PCR, the "gold standard" for molecular diagnostic assays, with the SDCR method by performing real-time amplification assays using human, bacterial and viral genetic materials. In the assays, SDCR demonstrated very high sensitivity and amplification efficiency. We found that the SDCR method provided an amplification factor above three, which noticeably outperformed that of PCR amplification and enabled a marked reduction in the number of cycles in comparison with PCR. Therefore, the new hybrid amplification technique could be extremely useful for the detection of genetic material and the development of new diagnostic kits.

molecular biology↗

bioRxiv2024

Comparison of Commercially Available Thermostable DNA Polymerases with Reverse-Transcriptase Activity in Coupled Reverse-Transcription Polymerase Chain Reaction Assays

Reverse-transcription polymerase chain reaction (RT-PCR) is an important tool for the detection of target RNA molecules and the assay of RNA pathogens. Coupled RT-PCR is performed with an enzyme mixture containing a reverse transcriptase and a thermostable DNA polymerase. To date, several biotechnological companies offer artificial thermostable DNA polymerases with a built-in reverse-transcriptase activity for use in the coupled RT-PCR instead of the enzyme mixtures. Here, we compared the artificial DNA polymerases and conventional enzyme mixtures for the RT-PCR by performing end-point and real-time RT-PCR assays using severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV2) RNA and endogenous mRNA molecules as templates. We found that the artificial enzymes were suitable for different RT-PCR applications, including SARS-CoV2 RNA detection, but not for long-fragment RT-PCR amplification.

bioengineering↗

bioRxiv2023

Sort-Seq: immune repertoire-based scRNA-Seq systematization

The functional programs selected by CD4+ helper (Th) T cell clones fundamentally determine the architecture of the immune response to distinct challenges. Advances in scRNA-Seq have enhanced our understanding of the diversity of these programs, yet the correspondence between scRNA-Seq clusters and previously characterized Th subsets remains unclear. In this study, we use immune repertoires to position phenotypically sorted Th subsets within scRNA-Seq data from three healthy donors. This approach, termed TCR-Track, and accurately maps Th1, Th1-17, Th17, Th22, Th2a, Th2, Tfh, and Treg subsets, outperforming CITE-Seq-based mapping. Remarkably, the mapping is tightly focused on specific scRNA-Seq clusters despite a four-year interval between the sorting of subsets and the effector CD4+ scRNA-Seq experiment. Thus, while transient T cell plasticity is commonly observed in functionally active T cell populations, TCR-Track reveals high intrinsic program sustainability of Th clones circulating in peripheral blood. Repertoire overlap analysis at the scRNA-Seq level confirms that circulating Th1, Th2, Th2a, Th17, Th22, and Treg subsets are clonally independent. However, a prominent clonal overlap between corresponding clusters indicates that cytotoxic CD4+ T cells differentiate from Th1 clones. More specifically, we demonstrate that sorted CCR10+ Th cells correspond to a specific Th22 scRNA-Seq cluster, while CCR10-CCR6+CXCR3-CCR4+ cells, traditionally sorted as the Th17 subset, represent a mixture of bona fide Th17 and clonally unrelated CCR10low Th22 cells, which may have confounded investigators in previous studies. This clear distinction of Th17 and Th22 subsets should influence vaccine and T cell based therapies development. Additionally, we show that SARS-CoV-2 infection is associated with transient IFN type 1 activation of naive CD4+ T cells, and an increased proportion of effector IFN- induced Th cells is associated with a moderate course of the disease but remains low in critical COVID-19 cases. Using integrated scRNA-Seq, TCR-Track, and CITE-Seq data from 122 donors, we provide a comprehensive Th scRNA-Seq reference that should facilitate further investigation of Th subsets in fundamental and clinical studies.

immunology↗

bioRxiv2022

SARS-CoV-2 Subunit Virus-Like Vaccine Demonstrates High Safety Profile and Protective Efficacy: Preclinical Study

Public health threat coming from a rapidly developing COVID-19 pandemic calls for developing safe and effective vaccines with innovative designs. This paper presents preclinical trial results of "Betuvax-CoV-2", a vaccine developed as a subunit vaccine containing a recombinant RBD-Fc fusion protein and betulin-based spherical virus-like nanoparticles as an adjuvant ("Betuspheres"). The aim of the study was to demonstrate vaccine safety in mice, rats, and Chinchilla rabbits through acute, subchronic, and reproductive toxicity studies. Along with safety, the vaccine demonstrated protective efficacy through SARS-CoV-2-neutralizing antibody production in mice, rats, hamsters, rabbits, and primates (rhesus macaque), and lung damage and infection protection in hamsters and rhesus macaque model. Eventually, "Betuvax-CoV-2" was proved to confer superior efficacy and protection against the SARS-CoV-2 in preclinical studies. Based on the above results, the vaccine was enabled to enter clinical trials that are currently underway.

pharmacology and toxicology↗

bioRxiv2018

Fragmentation Through Polymerization (FTP): A New Method to Fragment DNA for Next-Generation Sequencing

Fragmentation of DNA is the first and very important step in preparing nucleic acids for NGS. Here we report a novel Fragmentation Through Polymerization (FTP) technique, which is simple, robust and low-cost enzymatic method of fragmentation. This method generates double-stranded DNA fragments that are suitable for the direct use in NGS library construction, and allows to eliminate the need of an additional step of reparation of DNA ends.

molecular biology↗