Comparison of the hydrodynamic and Dirac models of the dispersion interaction between graphene and H, He∗{}^{\ast}, or Na atoms

The van der Waals and Casimir-Polder interaction of different atoms with graphene is investigated using the Dirac model which assumes that the energy of quasiparticles is linear with respect to the momentum. The obtained results for the van der Waals coefficients of hydrogen atoms and molecules and atoms of metastable He${}^{\ast}$ and Na as a function of separation are compared with respective results found using the hydrodynamic model of graphene. It is shown that, regardless of the value of the gap parameter, the Dirac model leads to much smaller values of the van der Waals coefficients than the hydrodynamic model. The experiment on quantum reflection of metastable He${}^{\ast}$ and Na atoms on graphene is proposed which is capable to discriminate between the two models of the electronic structure of graphene. In this respect the parameters of the phenomenological potential for both these atoms interacting with graphene described by different models are determined.Comment: 15 pages, 4 figure

Ergodicity criteria for non-expanding transformations of 2-adic spheres

In the paper, we obtain necessary and sufficient conditions for ergodicity (with respect to the normalized Haar measure) of discrete dynamical systems $$ on 2-adic spheres $\mathbf S_{2^{-r}}(a)$ of radius $2^{-r}$, $r\ge 1$, centered at some point $a$ from the ultrametric space of 2-adic integers $\mathbb Z_2$. The map $f\colon\mathbb Z_2\to\mathbb Z_2$ is assumed to be non-expanding and measure-preserving; that is, $f$ satisfies a Lipschitz condition with a constant 1 with respect to the 2-adic metric, and $f$ preserves a natural probability measure on $\mathbb Z_2$, the Haar measure $\mu_2$ on $\mathbb Z_2$ which is normalized so that $\mu_2(\mathbb Z_2)=1$

THE ROLE OF PREGNANCY-SPECIFIC GLYCOPROTEIN IN REGULATION OF MOLECULAR GENETIC DIFFERENTIATION MECHANISMS OF IMMUNE MEMORY T CELLS

The role of pregnancy-specific β1-glycoprotein (PSG) in the regulation of molecular genetic factors determining the functional activity of naїve T cells and T cells of immune memory in vitro was studied. Human PSG was isolated with a proprietary immuno-purification method using a biospecific sorbent followed by removing of immunoglobulin contamination with a HiTrapTM Protein G HP column. Physiological concentrations of PSG were used in the experiments. They corresponded to PSG levels in the peripheral blood of pregnant woman: 1, 10 and 100 μg/ml (I, II, III trimester, respectively). The objects of study were monocultures of naїve T cells (CD45RA+) and memory T cells (CD45R0+), obtained by immunomagnetic separation from the peripheral blood of women of reproductive age.It was established that at the level of naїve T cells (CD45RA+) PSG inhibited the expression of CD28 (1, 10, 100 μg/ml) and CD25 (100 μg/ml), without affecting the interleukin-2 (IL-2) production by these cells. At the same time, PSG in all concentrations studied suppressed the expression of CD25 at the immune memory T-cell (CD45R0+) surface but increased the IL-2 production. Expression of U2af1l4, Gfi1, hnRNPLL genes regulating the alternative splicing of the Ptprc gene encoding CD45 was also evaluated. It was found, that PSG reduced the expression of the Gfi1 (1, 10, 100 μg/ml), hnRNPLL (10, 100 μg/ml) genes, but increased the expression of the U2af1l4 gene (1, 10, 100 μg/ml) in the naїve T cells. It was shown that at the immune memory T-cells’ level the effects were similar, with PSG rendering them in all concentrations used. The revealed changes in the mRNA transcription of U2af1l4, Gfi1 and hnRNPLL genes in the studied T cell subsets may lead to the inhibition of CD45 “mature” isoform formation – CD45R0.Thus, PSG reduces the functional activity of naїve T cells and immune memory T cells associated with the expression of costimulation/activation molecules CD25 and CD28 and is involved in the regulation of Ptprc gene alternative splicing, which determines the ratio of CD45 molecule variants. Apparently, using these mechanisms, PSG regulates the functional activity of the memory T cell circulating pool, which is potentially capable of carrying out antigen-specific cytotoxic reactions against fetal antigens in vivo. In general, the data obtained broadens the notion of the PSG role in the regulation of molecular-genetic mechanisms of naїve T cells and immune memory T cells differentiation

Клеточные реакции CD3+ CD4+ CD45RO+ Т-лимфоцитов на дексаметазон в норме и при ревматоидном артрите в системе in vitro

The aim of the study was to analyze the influence of glucocorticoid (GC) dexamethasone (Dex) on changes in CD4+ T-cells expressing the surface molecule of activation (CD25, CD71, HLA-DR and CD95) and their ability to produce proinflammatory mediators in cultures of TCR-stimulated CD3+CD45RO+ T-lymphocytes obtained from healthy donors and patients with rheumatoid arthritis in vitro.Materials and methods. The study included 50 patients and 20 healthy donors. T-cell cultures (CD3+ CD45RO+) were obtained from mononuclear leukocytes of immunomagnetic separation (MACS® technology). As an activator of T-lymphocytes, antibiotic particles with biotinylated antibodies against CD2+, CD3+, CD28+, which simulate the process of costimulation of T cells by antigen-presenting cells, were used. The following concentrations of dexamethasone (2, 8, 16, 32, 64 mg) were used in the experiment. The change in the immunophenotype of T-lymphocytes was analyzed by flow cytofluoometry. The secretion of CD3+CD45RO+ T-cells of proinflammatory cytokines IL-2, IFNγ, TNFα, IL-17 and IL-21 was evaluated by enzyme-linked immunosorbent assay.Results. The general suppressor effect of Dex on CD3+CD45RO+ T-cell cultures mediated by a decrease in the number of CD4 + T cells expressing activation molecules (CD25) and proliferation (CD71), as well as inhibition of the production of inflammatory mediators: IFNγ, IL-2 and TNFα. It is shown that against the background of TCR activation Dex increases the number of CD4+CD95+HLA-DR+ cells in CD3+CD45RO+ cultures obtained from RA patients and does not change their content in the control. The correlations between the number of proinflammatory factors (IL-17, IL-21 and TNFα) in CD4+CD45RO+CD95+HLA-DR+ T cells in supernatants of cell cultures in RA patients indicate the presence of a pro-inflammatory potential of this population of T cells. We assume that the resistance of CD4+CD45RO+CD95+HLA-DR+ T cells in RA patients to the suppressor effect of GC generally leads to the preservation and enhancement of the functionality of autoreactive cells in the pathogenesis of RA. Целью исследования явился анализ влияния глюкокортикоида (ГК) дексаметазона (Dex) на изменение числа CD4+ Т-клеток, экспрессирующих поверхностные молекулы активации (CD25, CD71, HLA-DR и CD95), и их способности продуцировать провоспалительные медиаторы в культурах TCRстимулированных Т-лимфоцитов CD3+CD45RO+, полученных у здоровых доноров и больных ревматоидным артритом (РА), в системе in vitro. В исследование включены 50 больных и 20 условно здоровых доноров.Материал и методы. Культуры T-клеток (CD3+CD45RO+) получали из мононуклеарных лейкоцитов методом иммуномагнитной сепарации (технология MACS®). В качестве активатора Т-лимфоцитов использовали антибиотиновые частицы с биотинилированными антителами против CD2+, CD3+, CD28+ человека, имитирующие процесс костимуляции Т-клеток антиген-презентирующими клетками. В эксперименте использованы следующие концентрации дексаметазона – 2; 8; 16; 32; 64 мг. Методом проточной цитофлуориметрии проанализировано изменение иммунофенотипа Т-лимфоцитов; иммуноферментным анализом оценена секреция Т-клетками CD3+CD45RO+ провоспалительных цитокинов: IL-2, IFNγ, TNFα, IL-17 и IL-21.Результаты. Подтвержден общий супрессорный эффект Dex на культуры Т-клеток CD3+CD45RO+, опосредованный снижением числа Т-клеток CD4+, экспрессирующих молекулы активации (CD25) и пролиферации (CD71), а также угнетением продукции медиаторов воспаления: IL-2, IFNγ и TNFα. Показано, что на фоне TCR-активации Dex повышает число клеток CD4+CD95+HLA-DR+ в культурах СD3+CD45RO+, полученных от больных РА, и не изменяет их содержание в контроле. Корреляции между числом Т-клеток CD4+CD45RO+ CD95+HLA-DR+ с уровнем провоспалительных факторов (IL-17, IL-21 и TNFα) в супернатантах клеточных культур у больных РА свидетельствуют о наличии провоспалительного потенциала этой популяции Т-клеток. Предполагается, что резистентность Т-клеток CD4+CD45RO+CD95+HLA-DR+ больных РА к супрессорному действию ГК в целом приводит к сохранению и усилению функциональных возможностей аутореактивных клеток в патогенезе РА.

Significance of nutrient media choice for the long-term cultures of leukemic T-lymphoblasts

Correct choice of nutrient media for culturing different types of cells in various applications is one of the most important aspects of modern biotechnology, since chemical composition of the culture media largely contains the necessary metabolites to support certain cells’ growth lines outside the body. Jurkat line of human leukemic T-lymphoblast-like cells (hereinafter Jurkat T-cells) is actively used for in vitro modeling of intracellular signaling and activation of normal blood T-lymphocytes mediated by the T-cell receptor/CD3/ CD4 complex in toxicological studies of immune and secretory responses, to test medicinal substances and ions. Also, Jurkat T-cells are widely used for ex vivo testing in immunology, oncology, toxicology, orthopedics, and traumatology. The existing standards and numerous studies are mainly based on short-term in vitro cultivation of Jurkat T-cells in RPMI 1640 nutrient medium. Meanwhile, the issues of long-term maintenance of the growth of Jurkat T-cells culture are poorly presented in the research literature. This study aimed for studying the activity of Jurkat T-cells over 7 to 14 days of in vitro culture and comparing the relative value of RPMI 1640 and αMEM media for the behavior of immunocompetent tumor cells. Using flow cytometry, multiplex analysis, and phase contrast Cell-IQ microscopy, the proportions of living cells and those dying by apoptosis and necrosis, secretion of cytokines and chemokines, and the dynamics of cell biomass propagation were studied. It was found that the αMEM medium in the complete nutrient medium, as compared with RPMI 1640, is more appropriate to in vitro promotion of cell viability (increased proportion of viable cells by 13.5% at the day 14), their secretory ability for 23 из 27 tested biomolecules, shortened adaptation time (на 32%) in culture before growth initiation, 5-fold increase of the Jurkat Т-cell cellularity by the day 7. Potential significance of the chemical components of nutrient media and secreted biomolecules for these results is discussed. As based on the results obtained, we concluded on superior properties of αMEM medium for long-term in vitro cultures of Jurkat T-cells. Consequently, the in vitro testing of medical devices intended for long-term contact with the body, including those for cancer patients, using Jurkat T-cell leukemia line in RPMI 1640 medium, may lead to wrong predictions on their biocompatibility and potential antitumor activity

Astaxantin and Isoflavones Inhibit Benign Prostatic Hyperplasia in Rats by Reducing Oxidative Stress and Normalizing Ca/Mg Balance

Benign prostatic hyperplasia (BPH) is a common pathology among aging men. Despite the broad pharmacological interventions, the available remedies to treat BPH are yet not devoid of side effects. Herbal compounds are suggested to be an alternative option for the BPH treatment. In our study, we evaluated the effect of kudzu isoflavones and astaxanthin on the BPH animal model. The animals were randomly divided into five groups: control; testosterone-induced BPH group; and three BPH-induced groups, which received intragastrically for 28 days finasteride (5 mg/kg) as a positive control, isoflavones (200 mg/kg), and astaxanthin (25 mg/kg). BPH was induced by castration of animals and subsequent subcutaneous injections of prolonged testosterone (25 mg/kg). Prostate index and histology, biochemical parameters, and antioxidant activity were evaluated. A significant decrease in prostate weight, immunohistochemical markers, and normalization of prostate Ca/Mg ratio was found in all treatment groups. Astaxanthin treatment also resulted in decreased epithelial proliferation and normalized superoxide dismutase activity. In conclusion, both isoflavones and astaxanthin inhibited BPH development at a level comparable to finasteride in terms of prostate weight, prostatic epithelium proliferation, and prostate tissue cumulative histology score. These results suggest that isoflavones and especially astaxanthin could serve as a potential alternative therapy to treat BHP. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by Russian Science Foundation, grant number 20-65-47025

Разработка лабораторных моделей in vitro иммунного микроокружения опухоли для оценки параметров качества и специфической эффективности дендритно-клеточной вакцины

Purpose of the study: development of in vitro laboratory models to evaluate quality parameters and specific efficacy of dendritic cell vaccine (DCV).Material and Methods. Biological samples of malignant tumor patients treated with autologous dendritic cell vaccine (DC) were included into the study. Immature DCs (n=46) and mature DCs (n=56) were used to induce proliferation of antigen-specific T lymphocytes (n=227). Autologous tumor cells from skin melanoma (n=10) or sarcoma (n=8) patients in the xCELLigence® assay system were used to study the in vitro antitumor cytotoxic activity of generated CTLs (n=18). The secretion of cytokines and cytolytic proteins was studied by multiplex analysis. The subpopulation composition of effector T-lymphocytes was determined by flow cytometry.Results. We revealed that mature DCs (CD83+CD1a-) had a high expression of antigen presenting molecules (HLA-DR) and those providing migration of DCs into lymph nodes (CCR7) as well as costimulatory molecules CD80 and CD86 as compared to immature DCs (CD83-CD1a+). Induction of mature DCs was found to stimulate an increase in the relative content of proliferating T cells compared with stimulation of immature DCs (p<0.001) and specific PTA+ tumor lysate (p<0.001). When studying cytotoxic activity of effector T-lymphocytes, we developed 2D in vitro models using xCELLigence® analytical system and revealed 2 types of interaction: 1) in vitro model № 1 – decrease in cell index (CI) of autologous tumor cell culture in the presence of activated effector T lymphocytes; 2) in vitro model № 2 – no change in CI of autologous tumor cell culture when co-cultured with activated effector T cells compared to control (72 h observation). The results demonstrated cytotoxic activity of antigen-specific T lymphocytes due to high content of terminally differentiated cytotoxic T lymphocytes (TEMRA), GrB-producing CTLs, and cytokine secretion profile.Conclusion. Requirements for the quality of personalized autologous DCs, including control of immunophenotypic characteristics were developed, and functional activity of Tlymphocytes during induction of mature vaccine DCs was evaluated. A laboratory procedure was developed for quantitative assessment of cytotoxic activity of antigen-specific T-lymphocytes against autologous tumor using the xCELLigence® analytical system, thus allowing for personalized monitoring and predicting the effectiveness of DСV treatment.Цель исследования ‒ разработка in vitro лабораторных моделей для оценки параметров качества и специфической эффективности дендритно-клеточной вакцины (ДКВ).Материал и методы. В исследование включены биологические образцы больных злокачественными новообразованиями, получавших вакцинотерапию на основе аутологичных дендритных клеток (ДК). Для индукции пролиферации антигенспецифических Т-лимфоцитов (n=227) использовали незрелые ДК (n=46) и зрелые ДК (n=56). Для изучения противоопухолевой цитотоксической активности in vitro генерированных ЦТЛ (n=18) использовали аутологичные опухолевые клетки меланомы кожи (n=10) или сарком (n=8) пациентов в аналитической системе xCELLigence®. Секрецию цитокинов и цитолитических белков изучали методом мультиплексного анализа, субпопуляционный состав эффекторных Т-лимфоцитов определяли методом проточной цитометрии.Результаты. В работе показано, что зрелые ДК (CD83+CD1a-) отличаются высокой экспрессией молекул, презентирующих антиген (HLA-DR) и обеспечивающих миграцию ДК в лимфатические узлы (CCR7), а также костимулирующих молекул CD80 и CD86, по сравнению с незрелыми ДК (CD83-CD1a+). Установлено, что индукция зрелыми ДК стимулирует рост относительного содержания пролиферирующих Т-клеток по сравнению со стимуляцией незрелыми ДК (р<0,001) и специфическим РТА+ опухолевым лизатом (р<0,001). При изучении цитотоксической активности эффекторных Т-лимфоцитов разработана 2D in vitro модель с использованием аналитической системы xCELLigence® и выявлено 2 типа взаимодействия: 1) лабораторная модель № 1 – снижение клеточного индекса (CI) культуры клеток аутологичной опухоли в присутствии активированных эффекторных Т-лимфоцитов; 2) лабораторная модель № 2 – отсутствие изменений CI культуры клеток аутологичной опухоли при ее кокультивировании с активированными эффекторными Т-клетками по сравнению с контролем (72 ч наблюдения). Результаты демонстрируют цитотоксическую активность антиген-специфических Т-лимфоцитов, что обусловлено высоким содержанием терминальнодифференцированных цитотоксических Т-лимфоцитов (TEMRA), ЦТЛ, продуцирующих GrB, и профилем секреции цитокинов.Заключение. Разработаны требования к качеству персонализированной аутологичной ДКВ, включающие контроль иммунофенотипических характеристик, проведена оценка функциональной активности Т-лимфоцитов при индукции зрелыми вакцинными ДК. Разработан лабораторный регламент количественной оценки цитотоксической активности антиген-специфических Т-лимфоцитов в отношении аутологичной опухоли с использованием аналитической системы xCELLigence®, что позволит проводить персонализированный мониторинг и может прогнозировать эффективность проводимого лечения ДКВ

Особенности клеточного иммунитета и регенерации при алкогольном фиброзе печени

Purpose. The subpopulation composition of peripheral blood lymphocytes was evaluated in patients with alcoholic liver fibrosis (ALF).Materials and methods. The study included 62 patients with ALF; 15 patients abusing alcohol without liver fibrosis and 20 conditionally healthy donors. In samples of lysed peripheral blood, the number of cells bearing surface markers was determined by flow cytometry. In patients with ALF at terminal stages of fibrosis, significant lymphopenia was recorded with a change in the composition of the main subpopulations of lymphocytes relative to the values of conditionally healthy donors and the comparison group.Results. We identified in the blood of ALF patients with terminal (III–IV) stage (relative to control and comparison group) of the relative number of naive (TN) and central memory T-lymphocytes (TCM) associated with an increase in the number of effector cells (TEM and TEMRA) allows us to suggest in this category of patients the direct differentiation of TN and TCM lymphocytes to effector (TEM and TEMRA), which can aggravate the course of the tissue-destructive process due to the high biocidal activity of the latter. Elevated levels of hematopoietic (CD34 and CD133) cells in the peripheral blood at the initial and moderate stages. (I–II) fibrosis (relative to control and comparison group) may be due to persistent inflammation in the liver parenchyma and an increasing imbalance between the processes of its damage and reparative capabilities. Whereas the decrease in their number at the terminal station fibrosis may indicate an increasing decompensation and depletion of the regenerative potential of the organism in the final stages of the degenerative process.Conclusions. In general, the obtained data demonstrate new aspects of the immune regulation of the processes of fibrogenesis in chronic alcoholism.Цель. Оценка субпопуляционного состава лимфоцитов периферической крови у больных алкогольным фиброзом печени (АФП).Материалы и методы. В исследование были включены 62 больных АФП; 15 пациентов, злоупотребляющих алкоголем, без фиброза печени и 20 условно здоровых доноров. В образцах лизированной периферической крови методом проточной цитометрии определяли число клеток, несущих поверхностные маркеры.Результаты. У больных АФП на терминальных стадиях (ст.) фиброза регистрировалась значительная лимфопения с изменением состава основных субпопуляций лимфоцитов относительно значений условно здоровых доноров и группы сравнения. Выявленное нами в крови больных АФП с терминальными (III–IV) ст. заболевания снижение (относительно контроля и группы сравнения) относительного числа наивных (TN) и Т-лимфоцитов центральной памяти (ТСМ), ассоциированное с ростом количества эффекторных клеток (TEM и TEMRA), позволяет нам предположить у этой категории больных факт прямой дифференцировки лимфоцитов TN и ТСМ в эффекторные (TEM и TEMRA), что может усугублять течение тканедеструктивного процесса за счет высокой биоцидной активности последних. Повышенный уровень гемопоэтических (CD34 и CD133) клеток в периферической крови на начальных и умеренных (I–II) ст. фиброза (относительно контроля и группы сравнения) может быть обусловлен персистирующим воспалением в паренхиме печени и нарастающим дисбалансом между процессами ее повреждения и репаративными возможностями. Тогда как снижение их количества на терминальных ст. фиброза может свидетельствовать о нарастающей декомпенсации и истощении регенераторного потенциала организма на финальных этапах дегенеративного процесса.Заключение. В целом полученные данные демонстрируют новые аспекты иммунной регуляции процессов фиброгенеза при хроническом алкоголизм