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Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a binding partner of the phosphatase CD45, but its function remains poorly understood. Its close interaction with CD45 suggests that LPAP may potentially regulate CD45, but direct biochemical evidence for this has not yet been obtained. We found that in the Jurkat lymphoid cells the levels of LPAP and CD45 proteins are interrelated and well correlated with each other. Knockout of LPAP leads to the decrease in the surface expression of CD45, while its overexpression, on the contrary, caused its increase. No such correlation was found in the non-lymphoid K562 cells. We hypothesize that LPAP regulates expression level of CD45 and thus can affect lymphocyte activation.

Antigenic cartography is a tool for interpreting and visualizing antigenic differences between virus variants based on virus neutralization data. This approach has been successfully used in the selection of influenza vaccine seed strains. With the emergence of SARS-CoV-2 variants escaping vaccine-induced antibody response, adjusting COVID-19 vaccines has become essential. This review provides information on the antigenic differences between SARS-CoV-2 variants revealed by antigenic cartography and explores a potential of antigenic cartography-based methods (e.g., building antibody landscapes and neutralization breadth gain plots) for the quantitative assessment of the breadth of the antibody response. Understanding the antigenic differences of SARS-CoV-2 and the possibilities of the formed humoral immunity aids in the prompt modification of preventative vaccines against COVID-19.

The rapid emergence of evasive SARS-CoV-2 variants is an ongoing challenge for COVID-19 vaccinology. Traditional virus neutralization tests provide detailed datasets of neutralization titers against the viral variants. Such datasets are difficult to interpret and do not immediately inform of the sufficiency of the breadth of the antibody response. Some of these issues could be tackled using the antigenic cartography approach. In this study, we created antigenic maps using neutralization titers of sera from donors who received the Sputnik V booster vaccine after primary Sputnik V vaccination and compared them with the antigenic maps based on serum neutralization titers of Comirnaty-boosted donors. A traditional analysis of neutralization titers against the WT (wild-type), Alpha, Beta, Delta, Omicron BA.1, and BA.4/BA.5 variants showed a significant booster humoral response after both homologous (Sputnik V) and heterologous (Comirnaty) revaccinations against all of the studied viral variants. However, despite this, a more in-depth analysis using antigenic cartography revealed that Omicron variants remain antigenically distant from the WT, which is indicative of the formation of insufficient levels of cross-neutralizing antibodies. The implications of these findings may be significant when developing a new vaccine regimen.

Replication-incompetent adenoviral vectors have been extensively used as a platform for vaccine design, with at least four anti-COVID-19 vaccines authorized to date. These vaccines elicit neutralizing antibody responses directed against SARS-CoV-2 Spike protein and confer significant level of protection against SARS-CoV-2 infection. Immunization with adenovirus-vectored vaccines is known to be accompanied by the production of anti-vector antibodies, which may translate into reduced efficacy of booster or repeated rounds of revaccination. Here, we used blood samples from patients who received an adenovirus-based Gam-COVID-Vac vaccine to address the question of whether anti-vector antibodies may influence the magnitude of SARS-CoV-2-specific humoral response after booster vaccination. We observed that rAd26-based prime vaccination with Gam-COVID-Vac induced the development of Ad26-neutralizing antibodies, which persisted in circulation for at least 9 months. Our analysis further indicates that high pre-boost Ad26 neutralizing antibody titers do not appear to affect the humoral immunogenicity of the Gam-COVID-Vac boost. The titers of anti-SARS-CoV-2 RBD IgGs and antibodies, which neutralized both the wild type and the circulating variants of concern of SARS-CoV-2 such as Delta and Omicron, were independent of the pre-boost levels of Ad26-neutralizing antibodies. Thus, our results support the development of repeated immunization schedule with adenovirus-based COVID-19 vaccines., (© 2022. The Author(s).)

The parameters of the humoral response are an important immunological characteristic of donors who recovered from COVID-19 and vaccinated individuals. Analysis of the level of virus-binding antibodies has become widespread. The most accurate predictor of effective immune protection against symptomatic SARS-CoV-2 infection is the activity of virus-neutralizing antibodies. We determined virus-neutralizing activities in plasma samples of individuals (n = 111) who had COVID-19 from April to September 2020. Three independent methods were used: conventional with live virus, with virus-like particles pseudotyped with spike protein, and a surrogate virus-neutralization test (cVNT, pVNT and sVNT, respectively). For comparison, the levels of IgG, IgA and IgM antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein were also evaluated. The levels of virus-binding as well as virus-neutralizing antibodies in cVNT and pVNT showed high heterogeneity. A comparison of cVNT and pVNT results showed a high correlation, sVNT results also correlated well with both cVNt and pVNT. To the greatest extent, the level of IgG antibodies correlated with the results of cVNT, pVNT and sVNT. These results can be used in the selection of plasmas that are best suited for transfusion and treatment of acute COVID-19. In addition, data on the virus-neutralizing activity of plasma are important for the selection of potential donors, for the isolation of SARS-CoV-2-specific B-lymphocytes, in order to further generate monoclonal virus-neutralizing antibodies.

The O-polysaccharide (OPS) was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G2559 and studied by sugar analysis along with 1D and 2D 1 H and 13 C NMR spectroscopy. The following structure of the branched pentasaccharide repeating unit was established. The O-antigen gene cluster of Enterobacter cloacae G2559 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the O-antigen structure., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Both SARS-CoV-2 infection and vaccination have previously been demonstrated to elicit robust, yet somewhat limited immunity against the evolving variants of SARS-CoV-2. Nevertheless, reports performing side-by-side comparison of immune responses following infection vs. vaccination have been relatively scarce. The aim of this study was to compare B-cell response to adenovirus-vectored vaccination in SARS-CoV-2-naive individuals with that observed in the COVID-19 convalescent patients six months after the first encounter with the viral antigens. We set out to use a single analytical platform and performed comprehensive analysis of serum levels of receptor binding domain (RBD)-specific and virus-neutralizing antibodies, frequencies of RBD-binding circulating memory B cells (MBCs), MBC-derived antibody-secreting cells, as well as RBD-specific and virus-neutralizing activity of MBC-derived antibodies after Gam-COVID-Vac (Sputnik V) vaccination and/or natural SARS-CoV-2 infection. Overall, natural immunity was superior to Gam-COVID-Vac vaccination. The levels of neutralizing MBC-derived antibodies in the convalescent patients turned out to be significantly higher than those found following vaccination. Our results suggest that after six months, SARS-CoV-2-specific MBC immunity is more robust in COVID-19 convalescent patients than in Gam-COVID-Vac recipients. Collectively, our data unambiguously indicate that natural immunity outperforms Gam-COVID-Vac-induced immunity six months following recovery/vaccination, which should inform healthcare and vaccination decisions.

The development of effective vaccines against SARS-CoV-2 remains a global health priority. Despite extensive use, the effects of Sputnik V on B cell immunity need to be explored in detail. We performed comprehensive profiling of humoral and B cell responses in a cohort of vaccinated subjects (n = 22), and demonstrate that Sputnik vaccination results in robust B cell immunity. We show that B memory cell (MBC) and antibody responses to Sputnik V were heavily dependent on whether the vaccinee had a history of SARS-CoV-2 infection or not. 85 days after the first dose of the vaccine, ex vivo stimulated MBCs from the vast majority of Sputnik V vaccinees produced antibodies that robustly neutralized the Wuhan Spike-pseudotyped lentivirus. MBC-derived antibodies from all previously infected and some of the naïve vaccine recipients could also cross-neutralize Beta (B.1.351) variant of SARS-CoV-2. Virus-neutralizing activity of MBC-derived antibodies correlated well with that of the serum antibodies, suggesting the interplay between the MBC and long-lived plasma cell responses. Thus, our in-depth analysis of MBC responses in Sputnik V vaccinees complements traditional serological approaches and may provide important outlook into future B cell responses upon re-encounter with the emerging variants of SARS-CoV-2., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Byazrova, Kulemzin, Astakhova, Belovezhets, Efimov, Chikaev, Kolotygin, Gorchakov, Taranin and Filatov.)

The O-polysaccharide (OPS) was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3422 and studied by chemical methods, including sugar analyses, Smith degradation, and solvolysis with anhydrous trifluoroacetic acid, along with 1 H and 13 C NMR spectroscopy. The following structure of the branched tetrasaccharide repeating unit was established: The O-antigen gene cluster of Enterobacter cloacae G3422 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in a good agreement with the O-antigen structure., (Copyright © 2021. Published by Elsevier Ltd.)

Antisense gapmer oligonucleotides containing phosphoryl guanidine (PG) groups, e.g., 1,3-dimethylimidazolidin-2-imine, at three to five internucleotidic positions adjacent to the 3' and 5' ends were prepared via the Staudinger chemistry, which is compatible with conditions of standard automated solid-phase phosphoramidite synthesis for phosphodiester and, notably, phosphorothioate linkages, and allows one to design a variety of gapmeric structures with alternating linkages, and deoxyribose or 2'-O-methylribose backbone. PG modifications increased nuclease resistance in serum-containing medium for more than 21 days. Replacing two internucleotidic phosphates by PG groups in phosphorothioate-modified oligonucleotides did not decrease their cellular uptake in the absence of lipid carriers. Increasing the number of PG groups from two to seven per oligonucleotide reduced their ability to enter the cells in the carrier-free mode. Cationic liposomes provided similar delivery efficiency of both partially PG-modified and unmodified oligonucleotides. PG-gapmers were designed containing three to four PG groups at both wings and a central "window" of seven deoxynucleotides with either phosphodiester or phosphorothioate linkages targeted to MDR1 mRNA providing multiple drug resistance of tumor cells. Gapmers efficiently silenced MDR1 mRNA and restored the sensitivity of tumor cells to chemotherapeutics. Thus, PG-gapmers can be considered as novel, promising types of antisense oligonucleotides for targeting biologically relevant RNAs., Competing Interests: The authors declare no competing interests., (© 2021 Institute of Chemical Biology and Fundamental Medicine SB RAS.)

The O-antigen (O-polysaccharide) is an essential component of lipopolysaccharide on the surface of Gram-negative bacteria and plays an important role in interaction with host organisms. In this study, we investigated the chemical structure and characterized the gene cluster of Enterobacter cloacae K7 O-antigen. As judged by sugar analyses along with NMR spectroscopy data, E. cloacae K7 antigen has a tetrasaccharide O-unit with the following structure: →8)-β-Psep5Ac7Ac-(2 → 2)-β-l-Rhap-(1 → 4)-α-l-Rhap-(1 → 3)-α-d-Galp-(1→ The O-antigen gene cluster of E. cloacae K7 between conserved genes galF and gnd was sequenced. Most genes necessary for the O-antigen synthesis were found in the cluster and their functions were tentatively assigned by comparison with sequences in the available databases., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

O-polysaccharide (O-antigen, OPS) was isolated from the lipopolysaccharide of Pseudomonas veronii SHC-8-1 and studied by component analyses and 1D and 2D NMR spectroscopy. The following structure of the O-polysaccharide was established: where QuipNAc4N(dHh) is 2,4-diamino-2,4,6-trideoxy-dglucose (Bacillosamine) in which N-2 is acetylated and N-4 is acylated with 3,5-dihydroxyhexanoic acid (dHh). The O-antigen gene cluster of Pseudomonas veronii SHC-8-1 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the OPS structure., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Atypical mononuclear cells (AM) appear in significant numbers in peripheral blood of patients with Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM). We investigated the number and lineage-specific clusters of differentiation (CD) expression of atypical mononuclear cells in 110 children with IM using the anti-CD antibody microarray for panning leukocytes by their surface markers prior to morphology examination. The AM population consisted primarily of CD8+ T cells with a small fraction (0%-2% of all lymphocytes) of CD19+ B lymphocytes. AM amount in children with mononucleosis caused by primary EBV infection was significantly higher than for IM caused by EBV reactivation or other viruses and constituted 1%-53% of all peripheral blood mononuclear cells compared to 0%-11% and 0%-8%, respectively. Children failing to recover from classic IM associated with primary EBV infection within 6 months had significantly lower percentage of CD8+ AM compared to patients with normal recovery rate., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

A denitrifying bacterium Pseudomonas veronii A-6-5 was isolated from a deep aquifer contaminated with nitrates and uranium. The O-polysaccharide (OPS) was isolated by mild acid degradation of the lipopolysaccharide of P. veronii A-6-5 and studied using sugar analysis and 1D and 2D 1 H and 13 C NMR spectroscopy. The trisaccharide O-repeating unit was found to have the following structure: [Formula: see text] [Formula: see text] where Hb is 3-hydroxybutanoyl. The genome of P. veronii A-6-5 was sequenced and a respective OPS gene cluster was identified. Functions of the proteins encoded in the gene cluster, including the enzymes involved in the O-polysaccharide biosynthesis and glycosyl transferases, were putatively assigned by comparison with available database sequences. Formation of a new coordination bond between uranyl and the O-polysaccharide from P. veronii A-6-5 was demonstrated using FTIR spectroscopy; it may affect uranyl migration in the groundwaters due to its immobilization on microbial biofilms. Applied importance of this work is that the structure of the O-polysaccharide of a strain isolated from uranium-contaminated groundwater was determined and the character of interaction between the polysaccharide and the uranyl ion was established. The data obtained are of importance for development of the biotechnologies for treatment of uranium-contaminated groundwater and activated sludge., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The O-polysaccharide (O-antigen) of Escherichia coli SDLZB008 was isolated from the lipopolysaccharide and studied by sugar analyses along with 1 H and 13 C NMR spectroscopy. The following structure of the branched pentasaccharide repeating unit was established, which is unique among the known structures of bacterial polysaccharides: The O-antigen gene cluster of E. coli SDLZB008 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the O-polysaccharide structure., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The structure of the O-polysaccharide of an aerobic halophilic bacterium Salinicola salarius HO-14 isolated from a heavy oil reservoir with highly mineralized water was determined. The neutral O-polysaccharide of strain HO-14 was isolated from the lipopolysaccharide and studied by sugar analysis and NMR spectroscopy. The linear tetrasaccharide repeating unit was found to have the following structure: →2)-α-l-Rhap-(1 → 3)-β-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 2)-α-d-Manp-(1→., (Copyright © 2020. Published by Elsevier Ltd.)

Tn antigen is a tumor-associated antigen that appears on cancer cells as a result of aberrant O-glycosylation. The most studied form of Tn antigen is found in mucins, in particular, in mucin 1 (MUC1). Antibodies against this form of Tn antigen are used to diagnose tumors, as well as to generate T-killers with a chimeric receptor. Some carcinomas do not carry MUC1 and antibodies of a different specificity are required to detect Tn antigen on these cells. In our work, we searched for anti-Tn antibodies without preliminary assumptions about the proteins that may be carriers of the Tn antigen. For this purpose, we obtained several pairs of isogenic cell lines with the wild type and knockout of the Cosmc gene, which is essential for correct protein O-glycosylation. Using the created lines as immunogens, we generated a monoclonal antibody AKC3, which reacted with the Cosmc-deficient A549 lung adenocarcinoma cells and did not bind to the wild-type cells. Using mass spectrometry, as well as co-immunoprecipitation, it was shown that the AKC3 antibody recognized the Tn antigen in the context of CD44 protein - a protein important for tumor growth. The AKC3 antibody can be used for tumor diagnosis, and to generate T cells with a chimeric receptor for treatment of tumors that do not express mucins.

Biological activity of antisense oligonucleotides (asON), especially those with a neutral backbone, is often attenuated by poor cellular accumulation. In the present proof-of-concept study, we propose a novel delivery system for asONs which implies the delivery of modified antisense oligonucleotides by so-called transport oligonucleotides (tON), which are oligodeoxyribonucleotides complementary to asON conjugated with hydrophobic dodecyl moieties. Two types of tONs, bearing at the 5'-end up to three dodecyl residues attached through non-nucleotide inserts (TD series) or anchored directly to internucleotidic phosphate (TP series), were synthesized. tONs with three dodecyl residues efficiently delivered asON to cells without any signs of cytotoxicity and provided a transfection efficacy comparable to that achieved using Lipofectamine 2000. We found that, in the case of tON with three dodecyl residues, some tON/asON duplexes were excreted from the cells within extracellular vesicles at late stages of transfection. We confirmed the high efficacy of the novel and demonstrated that MDR1 mRNA targeted asON delivered by tON with three dodecyl residues significantly reduced the level of P-glycoprotein and increased the sensitivity of KB-8-5 human carcinoma cells to vinblastine. The obtained results demonstrate the efficacy of lipophilic oligonucleotide carriers and shows they are potentially capable of intracellular delivery of any kind of antisense oligonucleotides.

The O-polysaccharide (O-antigen, OPS) of Vibrio cholerae O68 was studied using chemical analyses and 1D and 2D NMR spectroscopy. The following structure of the tetrasaccharide repeating unit of the OPS was established: where Dhpa indicates (2S,4R)-2,4-dihydroxypentanoic acid existing mainly in the form of 1,4-lactone. Recently, (2R,4S)- and (2R,4R)-isomers of Dhpa have been found in the OPS of Providencia alcalifaciens O8 and O31, respectively. Functions of genes in the O-antigen gene cluster of Vibrio cholerae O68 were predicted according to the OPS structure established. These data provide a molecular basis for classification of V. cholerae strains., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a small transmembrane protein that is found in lymphocytes and is tightly associated with the phosphatase CD45. The function of LPAP is still unknown. Studies of the LPAP interactome may reveal new details of how C45 and lymphocyte signaling in general are regulated. LPAP binding partners were sought using coimmunoprecipitation coupled with mass spectrometry, stabilization of protein complexes with chemical crosslinkers, and Blue Native electrophoresis. In addition to CD45, several proteins were identified as LPAP partners, including CD71, CD98, cytoskeletal proteins, the amino acid transporter SLC1A4, and the cell signaling component HS1. It was confirmed that more than 70% of LPAP molecules were bound with CD45 in a 1 : 1 complex. The effect of CD45 on LPAP was studied in CEM and Jurkat cells with a CD45 knockout. The LPAP levels in the cells were 10% of the level in wild-type cells. In the absence of CD45, LPAP phosphorylation at Ser-153 and Ser-163 was not affected, whereas phosphorylation at Ser-99 and Ser-172 decreased significantly. Based on the results, CD45 was assumed to play a role in regulating LPAP expression and phosphorylation status.

Currently, more than 37 million individuals worldwide are infected with the human immunodeficiency virus (HIV). Antiretroviral therapy may control the viral infection but is incapable of eradicating it. It is important to understand how cells respond to HIV-1 infection and what cellular factors are involved in this process to develop novel classes of antiviral drugs. This review summarizes the current understanding of the HIV restriction mechanism. We discuss the ambiguous role of HIV restriction factors in viral infection and counteraction mediated by HIV-1 accessory proteins.

The O-polysaccharide (O-antigen) of Vibrio cholerae O14 was studied using chemical analyses and 1D and 2D NMR spectroscopy. The following structure of the repeating unit of the O-antigen was established: where GlcpN(SHb) indicates 2-deoxy-2-[(S)-3-hydroxybutanoylamino]-d-glucose. We found that Vibrio cholerae O14 is similar to that of O-polysaccharide of Azospirillum brasilense S17, which has been reported earlier. Moreover, we predicted functions of all the genes in the O-antigen gene cluster according to the structure established. Our study enriches the existing O-antigen database of Vibrio cholerae, and further facilitates the bacterial serotype identification., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

O-polysaccharide (O-antigen) was isolated from the lipopolysaccharide of Vibrio cholerae O100 and studied by component analyses and 1D and 2D NMR spectroscopy. The following structure of the O-polysaccharide was established: →3)-β-d-QuipNAc4N(dHh)-(1 → 3)-α-d-Fucp4N(RHb)-(1 → 3)-α-l-FucpNAc-(1→ where Hb and dHh indicate 3-hydroxybutanoyl and 3,5-dihydroxyhexanoyl, respectively. The O-antigen gene cluster of V. cholerae O100 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the OPS structure., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The acylation of unsymmetrical N -benzylbispidinols in aromatic solvents without an external base led to the formation of supramolecular gels, which possess different thicknesses and degrees of stability depending on the substituents in para-positions of the benzylic group as well as on the nature of the acylating agent and of the solvent used. Structural features of the native gels as well as of their dried forms were studied by complementary techniques including Fourier-transform infrared (FTIR) and attenuated total reflection (ATR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering and diffraction (SAXS). Structures of the key crystalline compounds were established by X-ray diffraction. An analysis of the obtained data allowed speculation on the crucial structural and condition factors that governed the gel formation. The most important factors were as follows: (i) absence of base, either external or internal; (ii) presence of HCl; (iii) presence of carbonyl and hydroxyl groups to allow hydrogen bonding; and (iv) presence of two (hetero)aromatic rings at both sides of the molecule. The hydrogen bonding involving amide carbonyl, hydroxyl at position 9, and, very probably, ammonium N-H⁺ and Cl - anion appears to be responsible for the formation of infinite molecular chains required for the first step of gel formation. Subsequent lateral cooperation of molecular chains into fibers occurred, presumably, due to the aromatic π-π-stacking interactions. Supercritical carbon dioxide drying of the organogels gave rise to aerogels with morphologies different from that of air-dried samples.

Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a molecular partner of CD45 phosphatase that plays a key role in the regulation of antigen-specific activation of lymphocytes. The functions of LPAP still remain unknown. We believe that studying LPAP phosphorylation pathways could shed light on its functions. In this work, we studied the phosphorylation of LPAP ectopically expressed in non-lymphoid cells in order to determine the effect of LPAP interaction partners on its phosphorylation. We found that phosphorylation at Ser153 and Ser163 in non-hematopoietic HEK293 cells was conserved, while phosphorylation at Ser99 and Ser172 was almost absent. The pattern of LPAP phosphorylation in K562 erythroid and U937 myeloid cells expressing endogenous CD45 protein was similar to that observed in T and B lymphocytes. We demonstrated for the first time that LPAP is a substrate for protein kinase CK2 that phosphorylates it at Ser153, presumably ensuring LPAP resistance to degradation.

The O-specific polysaccharide (O-antigen) is a part of the lipopolysaccharide on the cell surface of Gram-negative bacteria. The O-polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of Escherichia coli O27 and studied by sugar analysis and Smith degradation along with 1 H and 13 C NMR spectroscopy. The following structure of the branched hexasaccharide repeating unit was established, which is unique among known structures of bacterial polysaccharides:where GlcA is non-stoichiometrically O-acetylated at position 3 (∼22%) or 4 (∼37%). Functions of genes in the O-antigen gene cluster of E. coli O27 were tentatively assigned by comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Solid pseudopapillary tumor is a low-grade malignant neoplasm of the pancreas. The clinical manifestations are variable, ranging from an asymptomatic course to cases with severe symptoms that dramatically impair the patients' status. The paper describes the rare case of a solid pseudopapillary tumor in a 34-year-old woman, which was accompanied by difficulties in the interpretation of clinical data and morphological patterns.

A significant carbon diffusion mobility acceleration as a result of cyclic γ↔ε martensitic transformations in iron-manganese alloy is determined by one- and two-dimensional structure defects of ε-martensite with face-centered close-packed lattice. Such defects (dislocations, low angle sub-boundaries of dislocations, chaotic stacking faults) were formed during cyclic γ↔ε martensitic transformations. Peak carbon diffusion coefficient increase was observed under thermocycling when maximum quantity of lattice defects increase was fixed.

Monoclonal antibodies have found wide applications in the treatment of cancer, as well as of autoimmune, infectious, and other diseases. Several dozen new antibodies are currently undergoing different stages of clinical trials, and some of them will soon be added to the list of immunotherapeutic drugs. Most of these antibodies have been generated using hybridoma technology or a phage display. In recent years, new methods of obtaining human monoclonal antibodies have been actively developing. These methods rely on sequencing immunoglobulin genes from B lymphocytes, as well as on the creation of antibody-secreting stable B-cell lines. The term next-generation antibody-discovery platforms has already been established in the literature to refer to these approaches. Our review focuses on describing the results obtained by these methods.

Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a small transmembrane protein expressed exclusively in lymphocytes. LPAP is a component of a supramolecular complex composed of the phosphatase CD45, the co-receptor CD4, and the kinase Lck. In contrast to its immunologically important partners, the function of LPAP is unknown. We hypothesized that the biological role of LPAP may be determined by analyzing LPAP phosphorylation. In the present study, we identified LPAP phosphorylation sites by site-directed mutagenesis, phospho-specific antibodies, and protein immunoprecipitation coupled to mass spectrometry analysis. Our results confirmed previous reports that Ser-99, Ser-153, and Ser-163 are phosphorylated, as well as provided evidence for the phosphorylation of Ser-172. Using various SDS-PAGE techniques, we detected and quantified a set of LPAP phosphoforms that were assigned to a combination of particular phosphorylation events. The phosphorylation of LPAP appears to be a tightly regulated process. Our results support the model: following phorbol 12-myristate 13-acetate (PMA) or TCR/CD3 activation of T cells, LPAP is rapidly dephosphorylated at Ser-99 and Ser-172 and slowly phosphorylated at Ser-163. Ser-153 exhibited a high basal level of phosphorylation in both resting and activated cells. Therefore, we suggest that LPAP may function as a co-regulator of T-cell signaling.

An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae C4115 and studied by sugar analysis along with 1D and 2D 1 H and 13 C NMR spectroscopy. The following structure of the linear pentasaccharide repeating unit of the O-polysaccharide was established: →2)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 2)-α-d-Galp-(1 → 3)-α-d-FucpNAc-(1→ The O-antigen gene cluster of E. cloacae C4115 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in consistence with the O-polysaccharide structure. The O-antigen structure and gene cluster of E. cloacae C4115 are similar to those of E. cloacae G3421 studied by us earlier (Perepelov A.V. et al. Carbohydr. Res. 427 (2016) 55-59)., (Copyright © 2017. Published by Elsevier Ltd.)

On mild acid degradation of the lipopolysaccharide of Enterobacter cloacae C5529, the O-polysaccharide chain was cleaved at the linkages of 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Psep5Ac7Ac). The resultant oligosaccharide and an alkali-treated lipopolysaccharide were studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit of the O-polysaccharide was established: →4)-β-Psep5Ac7Ac-(2 → 3)-β-d-Galp-(1 → 6)-β-d-Galf-(1 → 3)-α-d-Galp-(1→ It differs from a structurally related O-polysaccharide of E. cloacae G3045 studied early (Perepelov, A. V.; Wang, M.; Filatov, A. V.; Guo, X.; Shashkov, A. S.; Wang, L.; Knirel, Y. A. Carbohydr. Res. 2015; 407:59-62) in positions of substitution of β-Psep5Ac7Ac (O-4 vs. O-8) and β-Galp (O-3 vs. O-6) and the absence of a side-chain α-Galp residue. The O-antigen gene clusters of E. cloacae C5529 and G3045 are organized identically and include genes with the same putative functions in the O-polysaccharide synthesis. Based on these and serological data, it is suggested to combine E. cloacae C5529 and G3054 in one O-serogroup as two subgroups., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Mild alkaline degradation of the lipopolysaccharide of Escherichia coli O80 afforded a polysaccharide, which was studied by sugar analysis, selective cleavage of glycosidic linkages, and (1)H and (13)C NMR spectroscopy. Solvolysis of the polysaccharide with CF3CO2H cleaved the linkages of α-Fuc and β-linked GlcNAc and GalNAc residues to give two disaccharides. The following structure of the hexasaccharide repeating unit of the O-polysaccharide was established: The polysaccharide repeat also contains a minor O-acetyl group but its position was not determined. The O-antigen gene cluster of E. coli O80 between the conserved galF and gnd genes was analyzed and found to be consistent with the O-polysaccharide structure established., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3421 and studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. In addition, partial solvolysis with anhydrous trifluoroacetic acid was applied, which cleaved selectively the α-l-rhamnopyranosidic linkages. The following structure of the branched hexasaccharide repeating unit was established. The O-polysaccharide studied shares the β-l-Rhap-(1→4)-α-l-Rhap-(1→2)-α-l-Rhap trisaccharide fragment with the O-polysaccharide of Shigella boydii type 18. The O-antigen gene cluster of E. cloacae G3421 was sequenced. Functions of genes in the cluster, including those for glycosyltransferases, were tentatively assigned by a comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The O-polysaccharide (O-antigen) of Escherichia coli O43 was isolated from the lipopolysaccharide and studied by chemical methods, including sugar analyses, Smith degradation, and solvolysis with anhydrous trifluoroacetic acid, along with (1)H and (13)C NMR spectroscopy. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established: [Formula: see text] Functions of genes in the O-antigen gene cluster of E. coli O43 were assigned by a comparison with sequences in the available databases and found to be in agreement with the O-polysaccharide structure., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The O-polysaccharide (O-antigen) of Escherichia coli O169 was studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. The following structure of the branched hexasaccharide repeating unit was established: [Formula: see text] The O-polysaccharide of E. coli O169 differs from that of Shigella boydii type 6 only in the presence of a side-chain glucose residue. A comparison of the O-antigen biosynthesis gene clusters between the galF to gnd genes in the genomes of the two bacteria revealed their close relationship. The glycosyltransferase gene responsible for the formation of the β-D-Glcp-(1 → 6)-α-D-Galp linkage in the O-antigen was identified in the gene cluster., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We describe a method for leukocyte sorting by a microarray of anti-cluster-of-differentiation (anti-CD) antibodies and for preparation of the bound cells for morphological or cytochemical examination. The procedure results in a "sorted" smear with cells positive for certain surface antigens localised in predefined areas. The morphology and cytochemistry of the microarray-captured normal and neoplastic peripheral blood mononuclear cells are identical to the same characteristics in a smear. The microarray permits to determine the proportions of cells positive for the CD antigens on the microarray panel with high correlation with flow cytometry. Using the anti-CD microarray we show that normal granular lymphocytes and lymphocytes with radial segmentation of the nuclei are positive for CD3, CD8, CD16 or CD56 but not for CD4 or CD19. We also show that the described technique permits to obtain a pure leukemic cell population or to separate two leukemic cell populations on different antibody spots and to study their morphology or cytochemistry directly on the microarray. In cases of leukemias/lymphomas when circulating neoplastic cells are morphologically distinct, preliminary diagnosis can be suggested from full analysis of cell morphology, cytochemistry and their binding pattern on the microarray.

The O-polysaccharides (O-antigens) were isolated by mild acid degradation of the lipopolysaccharide (LPS) of Escherichia coli O46 and O134. The structures of their linear tetrasaccharide repeating units were established by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy: [Formula: see text], where D-aThr indicates D-allothreonine and R indicates O-acetyl substitution (∼ 70% on aThr and ∼ 15% on GalNAc) in E. coli O46 whereas the O-acetylation is absent in E. coli O134. Functions of genes in the essentially identical O-antigen gene clusters of E. coli O46 and O134 were tentatively assigned by a comparison with sequences in available databases and found to be in agreement with the O-polysaccharide structures established., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3054 resulted in the cleavage of the O-polysaccharide at the linkage of residues of 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac) in the main chain. The resultant oligosaccharide and an alkali-treated lipopolysaccharide were studied by sugar analysis along with (1)H and (13)C NMR spectroscopy, and the following structure of the branched pentasaccharide O-unit of the O-polysaccharide was established: [structure: see text] The O-antigen gene cluster of E. cloacae G3054 between conserved genes galF and gnd was sequenced. Most genes necessary for the O-antigen synthesis were found in the cluster and their functions were tentatively assigned by comparison with sequences in the available databases., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Diffusion characteristics of cobalt atoms were investigated using radioactive isotope method in phase-hardened Fe-18wt.%Mn-2wt.%Si alloy. The observed significant increase of diffusion coefficient of cobalt atoms under the cyclic γ-ε-γ martensitic transformations was due to the action of two independent mechanisms - an athermal one and a thermally activated one. The first one arose from the direct γ-ε and the reverse ε-γ transformations with corresponding direct and reverse lattice shears during alternating stresses and simultaneous lattice restructuring. Another mechanism arose under the diffusion annealing of the phase-hardened alloy.

Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a transmembrane protein with unknown function. The available data on its close association with phosphatase CD45 and its phosphorylation depending on cell activation suggest that LPAP can play a significant role in the antigenic stimulation of lymphocytes. We have localized three antigenic epitopes of the LPAP molecule that can be detected using monoclonal antibodies prepared earlier. Experiments on reactions of antibodies with point mutants and shortened forms of the LPAP protein revealed regions of the amino acid sequence that correspond to the epitopes recognized by the antibodies.

The O-polysaccharide (O-antigen) of Escherichia coli O68 was studied by sugar analysis, partial solvolysis with anhydrous trifluoroacetic acid, and 1D and 2D (1)H and (13)C NMR spectroscopies. The following structure of the branched heptasaccharide repeating unit was established: [structure: see text]. The O-antigen gene cluster of E. coli O68 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the O-antigen structure., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

On mild acid degradation of the lipopolysaccharide of Enterobacter cloacae C6285, the O-polysaccharide was cleaved at residues of 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic acid (di-N-acetyllegionaminic acid, Leg5Ac7Ac) in the main chain. The resultant oligosaccharide and an alkali-treated lipopolysaccharide were studied by sugar analysis along with (1)H and (13)C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit of the linear O-polysaccharide was established: →4)-α-d-Galp-(1→4)-α-Legp5Ac7Ac-(2→3)-β-d-Galp-(1→3)-β-d-GalpNAc-(1→ The O-antigen gene cluster of E. cloacae C6285 was sequenced, the gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the O-polysaccharide structure., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

O-Polysaccharide (O-antigen) accompanied by a minor mannan was isolated from the lipopolysaccharide of Escherichia coli O39 and studied by component analyses, methylation, Smith degradation, mass spectrometry, and 1D and 2D NMR spectroscopy. In addition, a new approach, solvolysis with anhydrous trifluoroacetic acid, was applied to cleave selectively the rhamnosidic linkage. The following structure of the O-polysaccharide was established: α--D-Galpl-->3-->3)-β-D-Quip4N(R3Hb)-(1-->2)-α-D-Manp-(l-->4)-α-L-Rhap-(1-->3)-α-D-GlcpNAc-(1--> where D-Qui4N(R3Hb) indicates 4,6-dideoxy-4-[(R)-3-hydroxybutanoylamino]-d-glucose. The O-antigen gene cluster of E. coli O39 has been sequenced. The gene functions were tentatively assigned by a comparison with sequences in the available databases and found to be in agreement with the O-polysaccharide structure., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G2277 and studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. The following structure of the linear pentasaccharide repeating unit was established, where a galacturonic acid (GalA) residue is mono-O-acetylated at position either 2 or 3: The O-antigen gene cluster of E. cloacae G2277 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in agreement with the O-polysaccharide structure., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Novel hybrids of fluorescein-labeled poly(ethylene glycol)-modified single-walled carbon nanotubes (SWCNTs) with nucleic acids were prepared. 5'-Pyrene conjugates of oligodeoxyribonucleotides were used to construct the noncovalent hybrids, with the pyrene residues acting as anchor groups, immobilizing an oligonucleotide on the SWCNT surface. The hybrid formation characteristics were studied using ζ-potential measurements and adsorption isotherm plots. Transmission electron microscopy (TEM) of the samples stained with contrast agents proved that the pyrene conjugates of oligonucleotides were adsorbed onto the surfaces of the functionalized SWCNTs. On the basis of the MTT assay, the functionalized SWCNTs and their hybrids with oligonucleotides exhibited low toxicity toward HeLa, KB-3-1, and KB-8-5 cells. A TEM study of ultrathin sections of cells treated with SWCNTs revealed that the nanotubes directly interacted with the cellular surface.