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【Objective】 Escherichia coli phage (ECP) and Staphylococcus aureus phage (SAP) isolated from sewage were used as research objects, and their biological characteristics were analyzed to provide new experimental materials for the application of phages. 【Methods】 ECP and SAP were purified and cultured by double-layer agar method. Then a series of biological characteristics of these two phages were preliminarily analyzed by electron microscope observation, optimal multiplicity of infection (MOI) test, one-step growth curve test, temperature, pH, chloroform and ultraviolet sensitivity tests, respectively. 【Results】 The results of biological characteristics showed that ECP and SAP were both virulent phages, belonging to myoviridac family. Their optimal MOI was 10-1, and they had strong resistance to ultraviolet light. The cleavage volume of ECP was 76.3 PFU/cell, while that of SAP was 8.3 PFU/cell. ECP had a wide range of temperature tolerance and could stably survive at 30-50 ℃, while SAP was more sensitive to temperature and could be completely inactivated at 50 ℃ for 1 h. ECP could maintain a good lysis activity in the range of pH 5-11, while SAP in the range of pH 6-9. ECP had strong resistance to chloroform and was non-membranous phage, while SAP was more sensitive to chloroform and was a membranous phage. 【Conclusion】 ECP and SAP are both virulent phages and have strong resistance to ultraviolet light. The lysability, temperature, pH, and chloroform tolerance of ECP are stronger than those of SAP.
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Objective:To explore the effect of high mobility group box-1 protein (HMGB1) on the balance of Th17/Treg in patients with immune thrombocytopenia (ITP).Methods:A total of 30 patients who were first diagnosed as ITP in the Fifth People's Hospital of Datong from July 2017 to April 2018 were selected as the case group, and another 30 healthy volunteers in the corresponding period were taken as the control group. The proportion of Th17 and Treg cells was detected by using flow cytometry, and the concentration of HMGB1, interleukin (IL)-17 and transforming growth factor β (TGF-β) in plasma was tested by using enzyme-linked immunosorbent assay (ELISA). Isolated peripheral blood mononuclear cells (PBMC) were cultured in vitro. After the treatment with recombinant human HMGB1 (rhHMGB1), real-time polymerase chain reaction (RT-PCR) was applied to detect the mRNA expression changes in Treg cell transcription factor intracellular forkhead helix transcription factor 3 (Foxp3) and Th17 cell transcription factor retinoid related orphan receptor γt (RORγt). The differences of indicators in Treg cell transcription factor peripheral blood between the case group and the control group were compared, and the balance correlation between HMGB1 and Th17/Treg was analyzed.Results:Compared with the healthy control group, the proportion of Th17 cells and the expression level of HMGB1 and IL-17 in peripheral blood of ITP patients were increased (all P < 0.01), while the proportion of Treg cells and the level of TGF-β were decreased (all P < 0.01). The proportion of Th17 cells and the expression level of IL-17 and HMGB1 in peripheral blood of ITP patients were positively correlated with the concentration of HMGB1 (all P < 0.01); the proportion of Treg cells and the level of TGF-β were negatively correlated with the expression level of HMGB1 (all P < 0.01). In vitro experiments, the expression of intracellular RORγt mRNA was increased compared with the negative control group (1.50±0.24 vs. 0.93±0.22, t = 9.612, P < 0.01), and the expression of Foxp3 mRNA was decreased compared with the negative control group after the stimulation of PBMC by rhHMGB1 (0.72±0.19 vs. 1.08±0.18, t = 7.387, P < 0.01). Conclusion:The high level of HMGB1 in the peripheral blood of ITP patients induces Th17/Treg imbalance and aggravates inflammatory reactions, which may be an important cause of ITP.
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Objective@#To explore the effect of high mobility group box-1 protein (HMGB1) on the balance of Th17/Treg in patients with immune thrombocytopenia (ITP).@*Methods@#A total of 30 patients who were first diagnosed as ITP in the Fifth People's Hospital of Datong from July 2017 to April 2018 were selected as the case group, and another 30 healthy volunteers in the corresponding period were taken as the control group. The proportion of Th17 and Treg cells was detected by using flow cytometry, and the concentration of HMGB1, interleukin (IL)-17 and transforming growth factor β (TGF-β) in plasma was tested by using enzyme-linked immunosorbent assay (ELISA). Isolated peripheral blood mononuclear cells (PBMC) were cultured in vitro. After the treatment with recombinant human HMGB1 (rhHMGB1), real-time polymerase chain reaction (RT-PCR) was applied to detect the mRNA expression changes in Treg cell transcription factor intracellular forkhead helix transcription factor 3 (Foxp3) and Th17 cell transcription factor retinoid related orphan receptor γt (RORγt). The differences of indicators in Treg cell transcription factor peripheral blood between the case group and the control group were compared, and the balance correlation between HMGB1 and Th17/Treg was analyzed.@*Results@#Compared with the healthy control group, the proportion of Th17 cells and the expression level of HMGB1 and IL-17 in peripheral blood of ITP patients were increased (all P < 0.01), while the proportion of Treg cells and the level of TGF-β were decreased (all P < 0.01). The proportion of Th17 cells and the expression level of IL-17 and HMGB1 in peripheral blood of ITP patients were positively correlated with the concentration of HMGB1 (all P < 0.01); the proportion of Treg cells and the level of TGF-β were negatively correlated with the expression level of HMGB1 (all P < 0.01). In vitro experiments, the expression of intracellular RORγt mRNA was increased compared with the negative control group (1.50±0.24 vs. 0.93±0.22, t = 9.612, P < 0.01), and the expression of Foxp3 mRNA was decreased compared with the negative control group after the stimulation of PBMC by rhHMGB1 (0.72±0.19 vs. 1.08±0.18, t = 7.387, P < 0.01).@*Conclusion@#The high level of HMGB1 in the peripheral blood of ITP patients induces Th17/Treg imbalance and aggravates inflammatory reactions, which may be an important cause of ITP.
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Objective To analyze the relationships of high mobility group box 1 protein (HMGB1) with regulatory T cells (Treg), T helper 17 cells (Th17) and cytokine secrtion in peripheral blood of gravidas with preeclampsia(PE),and to investigate the mechanism of HMGB1 in regulating Th17/Treg ratio via receptor for advanced glycation end products (RAGE)-IL-6 pathway. Methods Forty gravi-das with mild(20 cases) and severe(20 cases) PE were recruited as experimental groups,20 heathy gravi-das in the third trimester of pregnancy were enrolled as control group. Concentrations of HMGB1,IL-6,IL-17 and TGF-β in peripheral blood of all subjects were determined by enzyme-linked immunosorbent assay (ELISA). Real-time quantitative PCR(RT-PCR) was used to detect the expression of RAGE at mRNA lev-el in peripheral blood mononuclear cells(PBMCs). The percentages of Treg and Th17 cells were determined by flow cytometry. RT-PCR was performed to analyze changes in the expression of RAGE,IL-6,Foxp3 and RORγt at mRNA level after the PBMCs isolated from 20 garvidas with PE were cultured in vitro and stimula-ted with recombinant human HMGB1 (rhHMGB1). Results The levels of HMGB1,IL-6,Th17 and IL-17 in peripheral blood of gravidas with PE were significantly higher than those in the normal pregnancy group. Moreover,HMGB1 level was positively correlated with IL-6 level and ratios of Th17/Treg and IL-17/TGF-β in preeclamptic pregancies. In vitro stimulation of PBMCs with rhHMGB1 significantly enhanced the expres-sion of RAGE,IL-6 and RORγt at mRNA level, but suppressed the expression of Foxp3 at mRNA level. Conclusion Enriched HMGB1 in plasma shifts the Th17/Treg balance towards Th17 dominance via the RAGE-IL-6 pathway, which exacerbates inflammation and participates in the onset of preeclampsia during pregnancy.
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Objective:To investigate the effect of the adoptive transfer of CD4+CD25+Foxp3+regulatory T cells ( iTregs) induced by 5-aza-2′-deoxycytidine (5AzaD) on pregnant outcome of the abortion-prone mice.Methods:Sixty cases of female CBA/J × male DBA/2J abortion-prone matings were taken as study group,the CD4+T cells from spleen of twenty female CBA/J mice were separated by magnetic activated cell sorting (MACS),5AzaD was applied to the conversion of CD4+CD25-T cells to iTregs,the expression of Foxp3 in Tregs was characterized by flow cytometry analysis before and after epigenetic modification.The purified iTregs were injected into abortion-prone mice on day 1 or 4 of pregnancy,respectively,which were used as therapy groups,and then the embryo resorption rate was counted on day 14 of pregnancy.Results:After the treatment of 5AzaD,the percentage of iTregs in CD4+T cells was (41.50±8.03)%.The embryonic absorption rates of the two therapy groups were 10.47%(on day 1 of pregnancy) and 21.69%(on day 4 of pregnancy) ,respectively ( P<0.05 ) .Conclusion: Epigenetic modication of CD4+CD25-T cells may solve the problem of nTregs deficiency,particularly adoptive therapy of 5AzaD-induced iTregs at early stage of pregnancy can maintain normal pregnancy.
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<p><b>OBJECTIVE</b>To investigate the expression of placenta-derived RASSF1A gene in maternal plasma during first and second trimesters, and to explore its value for the prediction of pre-eclampsia.</p><p><b>METHODS</b>For 325 pregnant women of the first trimester, free DNA of plasma samples was extracted at 7-12, 13-18, and 19-24 gestational weeks, respectively. Methylation-sensitive restriction enzyme digestion followed by fluorescence quantitative PCR (MSRE+ PCR) was employed for analyzing the concentrations of hypermethylated RASSF1A gene. Blood pressure, proteinuria and clinical feature were monitored at the same time. Those who had subsequently developed pre-eclampsia were selected as the pre-eclamptic group, 30 normal pregnant women were selected as the control group. Hypermethylated RASSF1A gene in maternal plasma was retrospectively analyzed. The relationship between clinical classification, type of pre-eclampsia and concentrations of the gene were further analyzed.</p><p><b>RESULTS</b>Twenty-six out of the 325 pregnant women developed pre-eclampsia as their only complication. At 13-18 gestational weeks, the mean concentrations of fetus-specific RASSF1A sequences were 141.62 copies/mL in maternal plasma of pre-eclamptic pregnancies, which was significantly greater than that of the controls (98.90 copies/mL). Fetus-derived RASSF1A levels were 2.03 fold higher in pre-eclamptic subjects than controls at 19-24 gestational weeks. There was a significant difference in the level of hypermethylated RASSF1A gene between the mild and severe pre-clamptic subjects at 13-24 gestational weeks (P< 0.05). The concentrations of the sequences were significantly higher in early-onset severe pre-eclampsia than late-onset severe pre-eclampsia at 19-24 gestational weeks (P< 0.05).</p><p><b>CONCLUSION</b>Altered expression of hypermethylated RASSF1A gene may be detected in maternal plasma during second trimester, which has important significance for early prediction of pre-eclampsia.</p>