Alterations in thymocyte populations under conditions of endotoxin tolerance / 中华医学杂志(英文版)

BACKGROUND@#Endotoxin tolerance (ET) is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide (LPS) leads to dramatically elevated survival. Accumulating evidence has shown that peripheral T cells contribute to the induction of ET. However, what happens to T cell development in the thymus under ET conditions remains unclear. The purpose of this study was to analyze the alterations in thymocyte populations (double-positive [DP] and single-positive [SP] cells) under ET conditions.@*METHODS@#Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups: a group examined 72 h after LPS injection (72-h group) and a group examined 8 days after LPS injection (8-day group). Injection of phosphate-buffered saline was used as a control (control group). Changes in thymus weight, cell counts, and morphology were detected in the three groups. Moreover, surface molecules such as CD4, CD8, CD44, CD69, and CD62L were analyzed using flow cytometry. Furthermore, proliferation, apoptosis, cytokine production, and extracellular signal-regulated kinase (ERK) pathway signaling were analyzed in thymocyte populations. The polymorphism and length of the T-cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) were analyzed using capillary electrophoresis DNA laser scanning analysis (ABI 3730).@*RESULTS@#Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET. Moreover, the proportions of DP cells (control: 72.130 ± 4.074, 72-h: 10.600 ± 3.517, 8-day: 84.770 ± 2.228), CD4+ SP cells (control: 15.770 ± 4.419, 72-h: 44.670 ± 3.089, 8-day: 6.367 ± 0.513), and CD8+ SP cells (control: 7.000 ± 1.916, 72-h: 34.030 ± 3.850, 8-day: 5.133 ± 0.647) were obviously different at different stages of ET. The polymorphism and length of TCR β chain CDR3 also changed obviously, indicating the occurrence of TCR rearrangement and thymocyte diversification. Further analysis showed that the expression of surface molecules, including CD44, CD69, and CD62L, on thymocyte populations (DP and SP cells) were changed to different degrees. Finally, the proliferation, apoptosis, cytokine production, and ERK pathway signaling of thymocyte populations were changed significantly.@*CONCLUSION@#These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.

AsO Up-Regulates the Proportion of CD4CD25CD127 Tregs in Peripheral Blood of Patients with Severe Aplastic Anemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of ATO on the proportion of Treg in the peripheral blood of patients with severe aplastic anemia (SAA) in vitro.</p><p><b>METHODS</b>The peripheral blood of 20 newlydiagnosed patients were collected, and the peripheral blood monomuclear cells (PBMNC) were extracted. After the PBMNC were treated with ATO of different concentrotions (0, 1, 2.5 and 5 µmol/L) for 96 hours, the proportion of CD44 CD25CD127 regulatatory T cells (Treg) were detected by flow cytometry. The expression levels of Foxp3 mRNA were detected by RT-PCR, and the levels of IFN-γ,IL-4,IL-17 and TGF-β1 were detected by ELTSA to verify the results of flow cytomery.</p><p><b>RESULTS</b>ATO significantly increased the proportion of Treg (P<0.01) at the concentration of 2.5 and 5 µmol/L, and the rising degree of Treg proportion improved with the increasing ATO concentration(r= 0.524). Treg proportion increased at a concentration of 1 µmol/L, but without statistical significance (P>0.05). At 1(P<0.05), 2.5(P<0.01) and 5 µmol/L(P<0.01), ATO significantly up-regulated the expression of Foxp3 mRNA, and the increase of Foxp3 mRNA positively and linearly correlated with the increase of Treg cell-frequency(r=0.523). ATO significantly reduced the levels of IFN-γ (at ATO 1,2.5 and 5 µmol/L, P<0.01), IL-4 (at ATO 2.5 µmol/L, P<0.01; at ATO 5 µmol/L, P<0.01) and IL-17(at ATO 2.5 µmol/L, P<0.05; at ATO 5 µmol/L, P<0.01). ATO had no significant effect on TGF-β1 at 1(P>0.05) and 2.5 µmol/L (P>0.05), but significantly reduced TGF-β1 level at 5 µmol/L (P<0.05).</p><p><b>CONCLUSION</b>ATO can mediate the immune regulation through up-regulating the proportion of Treg in peripheral blood of patients with SAA and reducing the levels of IFN-γ, IL-4 and IL-17.</p>

Effect of microRNA-7 knockdown on ConA-induced acute liver injury in mice / 中国病理生理杂志

AIM:To study the effect of microRNA-7 (miR-7) knockdown (KD) on concanavalin A (ConA)-induced acute liver injury (ALI) in mice.METHODS:Wild type (WT) mice and miR-7KD mice were received ConA (30 mg/kg) to induced acute liver injury model by intraperitoneal injection,and the morphological changes,liver weight and weight index were measured 48 h later.The pathological changes of the liver tissues were observed by HE staining.The levels of serum alanine aminotransferase (ALT),IL-4 and IFN-γ were detected by ELISA.The proportional changes of CD4 + T cells and the relative levels of IL-4 and IFN-γwere analyzed by flow cytometry.RESULTS:The color of the liver tissue became lighter,and the weight and weight index were changed significantly in miR-7KD mice compared with control group (P ＜ 0.05).HE staining showed that the inflammatory cell infiltration was increased in the liver of miR-7KD mice.Moreover,the level of serum ALT was significantly increased (P ＜ 0.05).The serum level of IFN-γelevated significantly (P ＜ 0.01),while the IL-4 levels decreased significantly (P ＜ 0.01) in the serum of miR-7KD mice.Furthermore,the proportion of CD4 + T cells and relative IFN-γcells increased obviously (P ＜ 0.01).CONCLUSION:miR-7 knockdown promotes the pathogenesis of the ConA-induced acute liver injury in mice.

Effect of microRNA-7 knockdown on ConA-induced acute liver injury in mice / 中国病理生理杂志

AIM:To study the effect of microRNA-7 (miR-7) knockdown (KD) on concanavalin A (ConA)-induced acute liver injury (ALI) in mice.METHODS:Wild type (WT) mice and miR-7KD mice were received ConA (30 mg/kg) to induced acute liver injury model by intraperitoneal injection,and the morphological changes,liver weight and weight index were measured 48 h later.The pathological changes of the liver tissues were observed by HE staining.The levels of serum alanine aminotransferase (ALT),IL-4 and IFN-γ were detected by ELISA.The proportional changes of CD4 + T cells and the relative levels of IL-4 and IFN-γwere analyzed by flow cytometry.RESULTS:The color of the liver tissue became lighter,and the weight and weight index were changed significantly in miR-7KD mice compared with control group (P ＜ 0.05).HE staining showed that the inflammatory cell infiltration was increased in the liver of miR-7KD mice.Moreover,the level of serum ALT was significantly increased (P ＜ 0.05).The serum level of IFN-γelevated significantly (P ＜ 0.01),while the IL-4 levels decreased significantly (P ＜ 0.01) in the serum of miR-7KD mice.Furthermore,the proportion of CD4 + T cells and relative IFN-γcells increased obviously (P ＜ 0.01).CONCLUSION:miR-7 knockdown promotes the pathogenesis of the ConA-induced acute liver injury in mice.