A potent, broadly neutralizing human monoclonal antibody that efficiently protects hACE2-transgenic mice from infection with the Wuhan, BA.5, and XBB.1.5 SARS-CoV-2 variants.

The COVID-19 pandemic has uncovered the high genetic variability of the SARS-CoV-2 virus and its ability to evade the immune responses that were induced by earlier viral variants. Only a few monoclonal antibodies that have been reported to date are capable of neutralizing a broad spectrum of SARS-CoV-2 variants. Here, we report the isolation of a new broadly neutralizing human monoclonal antibody, iC1.

Serial Llama Immunization with Various SARS-CoV-2 RBD Variants Induces Broad Spectrum Virus-Neutralizing Nanobodies.

The emergence of SARS-CoV-2 mutant variants has posed a significant challenge to both the prevention and treatment of COVID-19 with anti-coronaviral neutralizing antibodies. The latest viral variants demonstrate pronounced resistance to the vast majority of human monoclonal antibodies raised against the ancestral Wuhan variant. Less is known about the susceptibility of the evolved virus to camelid nanobodies developed at the start of the pandemic.

The Search for Single-Domain Antibodies Interacting with the Receptor-Binding Domain of SARS-CoV-2 Surface Protein.

We performed a search for nanoantibodies that specifically interact with the receptor-binding domain (RBD) of the SARS-CoV-2 surface protein. The specificity of single-domain antibodies from the blood sera of a llama immunized with RBD of SARS-CoV-2 surface protein S (variant B.1.

Polymer-Stabilized Elemental Boron Nanoparticles for Boron Neutron Capture Therapy: Initial Irradiation Experiments.

Sufficient boron-10 isotope (B) accumulation by tumor cells is one of the main requirements for successful boron neutron capture therapy (BNCT). The inability of the clinically registered B-containing borophenylalanine (BPA) to maintain a high boron tumor concentration during neutron irradiation after a single injection has been partially solved by its continuous infusion; however, its lack of persistence has driven the development of new compounds that overcome the imperfections of BPA. We propose using elemental boron nanoparticles (eBNPs) synthesized by cascade ultrasonic dispersion and destruction of elemental boron microparticles and stabilized with hydroxyethylcellulose (HEC) as a core component of a novel boron drug for BNCT.

Isolation of a panel of ultra-potent human antibodies neutralizing SARS-CoV-2 and viral variants of concern.

In the absence of virus-targeting small-molecule drugs approved for the treatment and prevention of COVID-19, broadening the repertoire of potent SARS-CoV-2-neutralizing antibodies represents an important area of research in response to the ongoing pandemic. Systematic analysis of such antibodies and their combinations can be particularly instrumental for identification of candidates that may prove resistant to the emerging viral escape variants. Here, we isolated a panel of 23 RBD-specific human monoclonal antibodies from the B cells of convalescent patients.

Gold Nanoparticles Permit In Situ Absorbed Dose Evaluation in Boron Neutron Capture Therapy for Malignant Tumors.

Boron neutron capture therapy (BNCT) is an anticancer modality realized through B accumulation in tumor cells, neutron irradiation of the tumor, and decay of boron atoms with the release of alpha-particles and lithium nuclei that damage tumor cell DNA. As high-LET particle release takes place inside tumor cells absorbed dose calculations are difficult, since no essential extracellular energy is emitted. We placed gold nanoparticles inside tumor cells saturated with boron to more accurately measure the absorbed dose.

Diversity of Immunoglobulin Light Chain Genes in Non-Teleost Ray-Finned Fish Uncovers IgL Subdivision into Five Ancient Isotypes.

The aim of this study was to fill important gaps in the evolutionary history of immunoglobulins by examining the structure and diversity of IgL genes in non-teleost ray-finned fish. First, based on the bioinformatic analysis of recent transcriptomic and genomic resources, we experimentally characterized the IgL genes in the chondrostean fish, (sterlet). We show that this species has three loci encoding IgL kappa-like chains with a translocon-type gene organization and a single VJC cluster, encoding homogeneous lambda-like light chain.

Radiobiological response of U251MG, CHO-K1 and V79 cell lines to accelerator-based boron neutron capture therapy.

In the current article, we provide in vitro efficacy evaluation of a unique accelerator-based neutron source, constructed at the Budker Institute of Nuclear Physics (Novosibirsk, Russian Federation), for boron neutron capture therapy (BNCT), which is particularly effective in the case of invasive cancers. U251MG, CHO-K1 and V79 cells were incubated and irradiated in various concentrations of boric acid with epithermal neutrons for 2-3 h in a plexiglass phantom, using 2.0 MeV proton energy and 1.

B cell-specific protein FCRLA is expressed by plasmacytoid dendritic cells in humans.

Background: Fc receptor-like A (FCRLA) is a unique member of a family of Fc receptor like-molecules that lacks a transmembrane region and is an ER-resident protein. In mice and humans, FCRLA has been known as a B cell specific protein. We report here that, in humans, FCRLA is also expressed in a subpopulation of plasmacytoid dendritic cells (pDCs).

[Impact of neutron radiation on the viability of tumor cells cultured in the presence of boron-10 isotope].

Objective: To investigate the impact of a neutron beam formed with the accelerator-based epithermal neutron source designed at the G.I. Budker Institute of Nuclear Physics (INP) on the viability of human and animal tumor cells cultured in the presence of boron-10 isotope.

Development and characterization of domain-specific monoclonal antibodies produced against human SLAMF9.

SLAMF9 is a member of the signaling lymphocyte-activating molecule (SLAM) immunoreceptor family. The SLAM family receptors are expressed in a broad range of immune cells and play an important role in immunity. To date, SLAMF9 is the least studied member of this family.

Characterization of human FCRLA isoforms.

FCRLA is an ER-resident B-cell specific protein. The exact function of this protein remains unclear although human FCRLA has been recently shown to interact with IgM, IgG and IgA. The retention of FCRLA in ER is mediated by the N-terminal domain.

[Expression of human B-cell specific receptor FCRL1 in normal individuals and in patients with autoimmune diseases].

The comparative analysis of expression level of FCRL1 gene encoding human B-cell surface receptor in healthy individuals and patients with autoimmune diseases was carried out. For the expression estimation we used results of DNA dot-hybridization on the membranes, containing cDNA samples from subpopulations of blood cells of patients with autoimmune diseases. The quantitative estimation of hybridization signals showed that expression level of FCRL1 gene in peripheral blood B-lymphocytes was significantly higher in patients with a multiple sclerosis, lupus anticoagulans, Takayasu's arteritis and also in von Willebrand disease than in healthy individuals.

Differential expression of FCRLA in naïve and activated mouse B cells.

FCRLA is an intracellular B cell protein that belongs to the FcR-like family. Using newly generated FCRLA-specific antibodies, we studied the constitutive expression pattern of mouse FCRLA and monitored changes during an immune response and following in vitro B cell activation. All B cell subpopulations examined expressed FCRLA.

[MHC-multimers and their application in studies of antiviral immune response].

Application of main histocompatibility complex tetrames (MHC-tetramers) for antigen specific T-cells detection and analysis coupled with flow cytometry opened new opportunities for T-cell response analysis. MHC-multimers allow the detection of T-cells against viral, cancer and vaccine antigens with exceptional sensitivity and specificity. This approach has become the "gold standard" for quantative analysis of T-cell immune response.

FCRLA is a resident endoplasmic reticulum protein that associates with intracellular Igs, IgM, IgG and IgA.

Fc receptor-like A (FCRLA) is an unusual member of the extended Fc receptor family. FCRLA has homology to receptors for the Fc portion of Ig (FCR) and to other FCRL proteins. However, unlike these other family representatives, which are typically transmembrane receptors with extracellular ligand-binding domains, FCRLA has no predicted transmembrane domain or N-linked glycosylation sites and is an intracellular protein.

FCRL6 receptor: expression and associated proteins.

FCRL6 receptor is a more recently identified representative of the FCRL family. We generated a panel of mouse mAbs to baculovirus-derived recombinant FCRL6 protein. The clone 7B2 was found to specifically recognize a 63kDa protein expressed preferentially on the surface of CD8 T and CD56 NK cells in human peripheral blood and spleen.

The amphibians Xenopus laevis and Silurana tropicalis possess a family of activating KIR-related Immunoglobulin-like receptors.

In this study, we searched the amphibian species Xenopus laevis and Silurana (Xenopus) tropicalis for the presence of genes homologous to mammalian KIRs and avian CHIRs (KRIR family). By experimental and computational procedures, we identified four related ILR (Ig-like Receptors) genes in S. tropicalis and three in X.

The Xenopus FcR family demonstrates continually high diversification of paired receptors in vertebrate evolution.

Background: Recent studies have revealed an unexpected diversity of domain architecture among FcR-like receptors that presumably fulfill regulatory functions in the immune system. Different species of mammals, as well as chicken and catfish have been found to possess strikingly different sets of these receptors. To better understand the evolutionary history of paired receptors, we extended the study of FcR-like genes in amphibian representatives Xenopus tropicalis and Xenopus laevis.

A direct antigen-binding assay for detection of antibodies against native epitopes using alkaline phosphatase-tagged proteins.

We describe a simple and efficient method to detect antibodies against native epitopes following immunization with denatured proteins and peptides. With this method, soluble antigens genetically fused with placental alkaline phosphatase (AP) are used as probes to detect antibodies immobilized on nitrocellulose membranes. The AP-tagged proteins can be produced in sufficient amounts using transient transfection of eukaryotic cells with an appropriate cDNA fragment in a commercial AP-tag vector.

Natural human gene correction by small extracellular genomic DNA fragments.

Classical gene targeting employs natural homologous recombination for a gene correction using a specially designed and artificially delivered DNA construct but the method is very inefficient. On the other hand, small DNA fragments in the form of tiny chromatin-like particles naturally present in blood plasma can spontaneously penetrate into human cells and cell nuclei. We hypothesized that these natural DNA nanoparticles with recombinagenic free ends might be effective agents for gene replacement therapy.

Generation and characterization of monoclonal antibodies specific for human FCRLA.

FCRLA is a recently identified intracellular protein structurally related to the classic Fc receptors and expressed primarily in the germinal centers of B cells. We generated six monoclonal antibodies (MAbs) specific to the human protein. The MAbs recognize three different epitopes, which were shown to be localized on the D3 domain of the FCRLA molecule.

Qualitative and quantitative characteristics of the extracellular DNA delivered to the nucleus of a living cell.

Background: The blood plasma and other intertissue fluids usually contain a certain amount of DNA, getting there due to a natural cell death in the organism. Cells of this organism can capture the extracellular DNA, whereupon it is delivered to various cell compartments. It is hypothesized that the extracellular DNA is involved in the transfer of genetic information and its fixation in the genome of recipient cell.