Effect of Short Peptides of Pregnancy-Specific ß1-Glycoprotein on Differentiation of Human Regulatory T Cells In Vitro and on Their Cytokine Profile.

Pregnancy-specific ß1-glycoprotein (PSG), one of the most important proteins of pregnancy, has a pronounced immunosuppressive effect. Short peptides of PSG, the so-called SLiMs (short linear motifs), are promising molecules for mild immunosuppression. We studied in vitro effect of short PSG peptides (YACS, YQCE, YVCS, and YECE) on differentiation and cytokine profile of human T-regulatory lymphocytes (Treg). T helpers isolated from the peripheral blood and polarized into the Treg phenotype with a T-cell activator (anti-CD2/3/28) and the cytokines IL-2 and transforming grown factor ß (TGFß) were used. PSG peptides were shown to have no direct modulatory effect on Treg differentiation in a culture of CD4+ cells polarized to the Treg phenotype. At the same time, PSG peptides had no effect on the viability and number of CD4+ cells in the in vitro culture. PSG peptides also had no effect on the levels of TNFα, IL-8, IL-2, macrophage inflammatory protein 1ß, IL-17, IL-10, IL-6, granulocyte-macrophage CSF, monocyte chemoattractant protein 1, IL-13, IL-5, IL-7, IL-12(p70), IL-1ß, granulocyte CSF, IL-4, but decreased IFNγ levels. The observed ability of the YQCE peptide to reduce the production of this proinflammatory Th1 cytokine by T helper cells can be interpreted as a positive effect. Our findings can be used for further development of safe peptide drugs based on SLiMs sequences.

Effect of PEGylated Graphene Oxide Nanoparticles on the Metabolism of Jurkat Cells.

The effect of graphene oxide (GO) nanoparticles of 100-200 nm in size coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol at concentrations of 5 and 25 µg/mL on the metabolism of Jurkat tumor cells was studied. It was found that LP-GO nanoparticles at a concentration of 25 µg/mL can enhance basal glycolysis of Jurkat T-lymphocyte tumor cell line cells, while LP-GO and BP-GO at the same concentration can reduce the indicators of compensatory glycolysis. Despite this, GO nanoparticles coated with linear and branched PEG at a concentration of 5 µg/mL do not have pronounced effects on oxidative phosphorylation and glycolysis of Jurkat cells and could therefore be safe for activated T cells.

The Role of Recombinant Glycodelin in the Differentiation of Regulatory T-Lymphocytes.

The effect of recombinant glycodelin (GdA) on the number of T-regulatory lymphocytes (Treg) in a culture of activated CD4+ lymphocytes was investigated, while simultaneously assessing the proliferative status of the cells. Recombinant GdA from E. coli and from HEK293 cells were used in the study at concentrations of 0.2; 2 and 10 µg/mL. It was found that only a low concentration (0.2 µg/mL) of recombinant GdA of bacterial origin reduced the number of proliferating CD4+ lymphocytes as well as the number of Treg (CD4+CD25highCD127-/low) in the experimental system in vitro.

Graphene Oxide Nanoparticels Interaction with Jurkat Cell Line in Cell-IQ System.

In recent years, materials based on graphene oxide (GO) have been actively studied for their use in biomedicine. The aim of our study was to investigate the increase in cell mass and viability of Jurkat tumor line T cells during 24 h of contact with GO nanoparticles in the Cell-IQ system of intravital observation. We used nanoparticles of different sizes coated with linear or branched polyethylene glycol (PEG) at concentrations of 5 and 25 µg/mL. It was shown for the first time that direct contact with GO nanoparticles reduced the growth in cell mass at the visualization points by more than twofold, regardless of nanoparticle size and concentration. Moreover, the number of live cells in the culture decreased by 5-9% after 24 h of monitoring. Thus, PEG-coated GO nanoparticles were found to suppress the proliferation and viability of Jurkat cell line T lymphocytes.

[The role of alpha-fetoprotein in regulation of the cytokine profile of activated T-helpers and their conversion in Th17 phenotype]. / Rol' al'fa-fetoproteina v reguliatsii tsitokinovogo profilia aktivirovannykh T-khelperov i ikh konversii v fenotip Th17.

We studied the effect of the native (non-recombinant) alpha-fetoprotein (AFP) on differentiation, proliferation, and cytokine profile of activated helper T cells 17 (Th17). The object of the study was a culture of isolated by immunomagnetic separation helper T cells (CD4+), induced into the Th17 phenotype by using TCR-activator and proinflammatory cytokines (IL-1ß and IL-6). AFP had not significant effect on the frequency of Th17 cells (ROR-γτ+) in the helper T cell culture, and did not affect proliferation of these cells, as measured by Ki-67 expression. Evaluation of the cytokine profile of culture supernatants by using the Luminex xMAP technology, revealed that AFP did not affect the levels of IL-4, IL-5, IL-7, IL-8, IL-10, IL-17, IFN-γ and TNF-α, but at concentrations of 50 IU/ml and 100 IU/ml it increased IL-2 production by activated helper T cells. At the same time, AFP suppressed the synthesis of G-CSF and GM-CSF (10 IU/ml), but stimulated the production of CCL4/MIP-1ß (100 IU/ml) and CCL2/MCP-1 chemokines (10 IU/ml and 50 IU/ml).

Development of an Immunosorbent for Solid-Phase NMR-Based Assay.

The conditions for constructing an immunosorbent reagent for solid-phase NMR analysis were optimized. For this purpose, we increased the area of ​​the sensitized portion of the membrane to fit the relaxometer coil size and added the agent sorption buffer. This provided the penetration of the anti-ligand molecules into the membrane thickness and their uniform distribution.

α-Fetoprotein Influence on the Conversion of Naïve T-Helpers into Memory T-Cell Effector Subpopulations.

The effect of native α-fetoprotein (AFP) on the conversion of naïve T-helpers into central memory T-cells (TCM) and effector subpopulations of the preterminally differentiated (TEM) and terminally differentiated (TEMRA) memory T-cells was studied. AFP was found to prevent the conversion of naïve T-helpers into effector subpopulations of memory T cells (TEM and TEMRA) while reducing the total production of IL-4 and IFN-γ by the studied cell populations. The data reveal a new role of AFP in the immune tolerance formation during pregnancy.

The role of human chorionic gonadotropin in regulation of naïve and memory T cells activity in vitro.

The role of human chorionic gonadotropin (hCG) in the regulation of molecular genetics factors determining the functional activity of human naïve and memory T cells in vitro was studied. It was found that hCG (10 and 100IU/ml) inhibited CD28 and CD25 expression on the naïve T cells (CD45RA+) and CD25 expression on the memory T cells (CD45R0+). hCG didn't affect the CD71 proliferation marker expression in total. Nevertheless, hCG reduced the percentage of proliferating memory T cells with simultaneous suppression of CD71 expression on proliferating CD45R0+cells. In parallel, expression of U2af1l4, Gfi1, and hnRNPLL genes, which are Ptprc gene alternative splicing regulators was evaluated. It was established that hCG stimulated the expression of U2af1l4 and hnRNPLL genes, responsible for the assembly of CD45R0 in memory T cells, but reduced the expression of Gfi1 in these cells. In general, hCG promotes the differentiation of memory T cells by increasing of CD45R0 expression, but inhibits proliferation and CD25 expression which reflects their functional activity.

[The influence of chorionic gonadotropin on phenotype conversion and hTERT gene expression by T-lymphocytes of different degrees of differentiation]. / Vliianie khorionicheskogo gonadotropina na konversiiu fenotipa i ékspressiiu gena hTERT T-limfotsitami raznoi stepeni differentsirovki.

The effects of chorionic gonadotropin (hCG) on the expression of the hTERT gene in combination with the conversion of the phenotype of naive T-cells and T-cells of immune memory in vitro were studied. hCG inhibited expression of hTERT mRNA in naive T-cells (CD45RA+) and immune memory T cells (CD45RO+), causing a decrease in the replicative potential of the cells. The presence of hCG in the culture led to the conversion of the phenotype of T-lymphocytes. hCG reduced the number of proliferating T-cells of immune memory, estimated by phenotypic signs by differential gating. hCG (10 IU/ml and 100 IU/ml) inhibited expression of CD25 by the studied populations, but did not modulate expression of the CD71 proliferation marker. Thus, hCG inhibited the functional activity of naive T-cells and T-cells of immune memory, which, in the context of pregnancy, can contribute to the formation of immune tolerance to the semi-allogenic fetus.

Role of the pregnancy-specific glycoprotein in regulation of the cytokine and chemokine profiles of intact mononuclear cells.

The effect of human pregnancy-specific glycoprotein (PSG) on the cytokine and chemokine production in vitro by intact mononuclear cells was studied by the method of flow fluorimetry. PSG inhibited production of the proinflammatory cytokines IL-6, IL-8, IL-17, IFN-γ, and TNF-α and chemokines CCL3/MIP-1α, CCL4/MIP-1ß, CCL2/MCP-1; at the same time, PSG stimulated IL-12(p70) production. Simultaneously with increasing the VEGF level, PSG inhibited production of IL-9, IL-13, G-CSF, and GM-CSF. The PSG effect discovered can be interpreted as a contribution into the immune tolerance formation during pregnancy.

The effect of pregnancy-specific ß1-glycoprotein 1 on the transcription factor FOXP3 expression by immunocompetent cells.

The role of human pregnancy-specific ß1-glycoprotein (PSG) in the regulation of expression of the transcription factor FOXP3 was studied. It is found that, under conditions of directed induction of phenotypic changes in CD4+ lymphocytes to regulatory T cells (Treg), PSG at high concentrations (10 and 100 µg/mL) increased FOXP3 expression. The evaluation of the spontaneous expression level of FOXP3 mRNA showed that PSG (1 and 100 µg/mL) stimulated the expression of this factor in mononuclear cells and isolated CD4+ lymphocytes. Thus, PSG stimulates FOXP3 expression in immunocompetent cells.