OX40/OX40L costimulation affects induction of Foxp3+ regulatory T cells in part by expanding memory T cells in vivo

OX40 is a member of the TNFR superfamily and has potent T cell costimulatory activities. OX40 also inhibits the induction of Foxp3(+) regulatory T cells (Tregs) from T effector cells, but the precise mechanism of such inhibition remains unknown. In the present study, we found that CD4(+) T effector cells from OX40 ligand-transgenic (OX40Ltg) mice are highly resistant to TGF-beta mediated induction of Foxp3(+) Tregs, whereas wild-type B6 and OX40 knockout CD4(+) T effector cells can be readily converted to Foxp3(+) T cells. We also found that CD4(+) T effector cells from OX40Ltg mice are heterogeneous and contain a large population of CD44(high)CD62L(-) memory T cells. Analysis of purified OX40Ltg naive and memory CD4(+) T effector cells showed that memory CD4(+) T cells not only resist the induction of Foxp3(+) T cells but also actively suppress the conversion of naive CD4(+) T effector cells to Foxp3(+) Tregs. This suppression is mediated by the production of IFN-gamma by memory T cells but not by cell-cell contact and also involves the induction of T-bet. Importantly, memory CD4(+) T cells have a broad impact on the induction of Foxp3(+) Tregs regardless of their origins and Ag specificities. Our data suggest that one of the mechanisms by which OX40 inhibits the induction of Foxp3(+) Tregs is by inducing memory T cells in vivo. This finding may have important clinical implications in tolerance induction to transplanted tissues.     

Genetic diversity in Artemisia halodendron (Asteraceae) based on chloroplast DNA psbA–trnH region from different hydrothermal conditions in Horqin sandy land, northern China

The genetic diversity of Artemisia halodendron (Asteraceae), a constructive and dominant species in the Horqin sandy land, was investigated to examine the genetic relationships with different hydrothermal regions in the Horqin sandy land. We sequenced chloroplast DNA (cpDNA) fragments psbA–trnH of 243 plants from ten populations across the Horqin sandy land. The analyses of cpDNA variation identified seven haplotypes. A high level of haplotype diversity (H _d = 0.831) and low level of nucleotide diversity (π = 0.0018) were detected. Haplotypes clustered into three tentative clades. Low genetic differentiation among regions was consistently indicated by hierarchical analyses of molecular variance (AMOVA).     

Candidate gene expression affects intramuscular fat content and fatty acid composition in pigs

The objective of this study was to correlate the expression pattern of candidate genes with the intramuscular fat (IMF) content and fatty acid composition of the Longissimus dorsi muscle of Duroc × Shanzhu commercial crossbred pigs. Animals of both sexes were slaughtered at a body weight of about 90 kg. The IMF content and fatty acid composition of the Longissimus dorsi muscle were measured and correlated with candidate genes mRNA expression (AdPLA, ADRB3, LEPR, MC4R, PPARγ, PPARα, LPL, PEPCK, and SCD). Females presented higher IMF content (p < 0.05) than males. The total saturated fatty acid (SFA) in males was greater (p < 0.01), whereas the total monounsaturated fatty acid (MUFA) (p < 0.01) and polyunsaturated fatty acid (PUFA) (p < 0.05) were lower than in females. The expressions of AdPLA, MC4R, PEPCK, and SCD correlated with the IMF content (p < 0.05). AdPLA showed a positive association with MUFA and a negative association with SFA (p < 0.05). LEPR and MC4R were both positively and significantly associated with C18:3 and C20:0 (p < 0.05). PPARα and PPARγ were negatively correlated with SFA, and PPARγ was positively associated with MUFA (p < 0.05). LPL was positively associated with MUFA and negatively associated with SFA (p < 0.05). PEPCK was negatively correlated with PUFA (p < 0.05). SCD was positively associated with MUFA (p < 0.05). The revealed correlations may confirm that these candidate genes are important for fat deposition and fatty acid composition in pigs, and the evaluation and use of these genes may be useful for improving porcine meat quality.     

Primate pelvic anatomy and implications for birth

The pelvis performs two major functions for terrestrial mammals. It provides somewhat rigid support for muscles engaged in locomotion and, for females, it serves as the birth canal. The result for many species, and especially for encephalized primates, is an ‘obstetric dilemma’ whereby the neonate often has to negotiate a tight squeeze in order to be born. On top of what was probably a baseline of challenging birth, locomotor changes in the evolution of bipedalism in the human lineage resulted in an even more complex birth process. Negotiation of the bipedal pelvis requires a series of rotations, the end of which has the infant emerging from the birth canal facing the opposite direction from the mother. This pattern, strikingly different from what is typically seen in monkeys and apes, places a premium on having assistance at delivery. Recently reported observations of births in monkeys and apes are used to compare the process in human and non-human primates, highlighting similarities and differences. These include presentation (face, occiput anterior or posterior), internal and external rotation, use of the hands by mothers and infants, reliance on assistance, and the developmental state of the neonate.     

刺五加和短梗五加叶片初生代谢的发育特异性调控研究

利用GC-MS技术对刺五加（Acanthopanax senticosus（Rupr. et Maxim.） Harms）和短梗五加（Acanthopanax sessiliflorus（Rupr. et Maxim.） Seem）叶片初级代谢产物进行了代谢组学分析,运用PCA和OPLS-DA方法分析后,将刺五加和短梗五加叶片划分为3个发育时期：生长期（Growth period）、旺盛期（Exuberant period）、凋落期（Autumn period）。刺五加叶片3个时期筛选出糖类、氨基酸、有机酸、脂肪酸、多元醇等共53个差异化合物,短梗五加叶片3个时期筛选出糖类、氨基酸、有机酸、脂肪酸、多元醇等共51个差异化合物。进一步分析表明,刺五加和短梗五加叶片在旺盛期和凋落期之间差异化合物最多,其中刺五加主要是糖类、有机酸;短梗五加则除了上述两类化合物外,还包括脂肪酸、多胺类化合物。两者作为同属植物,在差异化合物的组成类型方面具有较高的相似性。结果初步揭示了2种同属药用植物叶片不同时期初级代谢物的积累模式,为2种植物叶片利用提供理论基础。     

A PCR-Based Method to Construct Lentiviral Vector Expressing Double Tough Decoy for miRNA Inhibition

DNA vector-encoded Tough Decoy (TuD) miRNA inhibitor is attracting increased attention due to its high efficiency in miRNA suppression. The current methods used to construct TuD vectors are based on synthesizing long oligonucleotides (~90 mer), which have been costly and problematic because of mutations during synthesis. In this study, we report a PCR-based method for the generation of double Tough Decoy (dTuD) vector in which only two sets of shorter oligonucleotides (< 60 mer) were used. Different approaches were employed to test the inhibitory potency of dTuDs. We demonstrated that dTuD is the most efficient method in miRNA inhibition in vitro and in vivo. Using this method, a mini dTuD library against 88 human miRNAs was constructed and used for a high-throughput screening (HTS) of AP-1 pathway-related miRNAs. Seven miRNAs (miR-18b-5p, -101-3p, -148b-3p, -130b-3p, -186-3p, -187-3p and -1324) were identified as candidates involved in AP-1 pathway regulation. This novel method allows for an accurate and cost-effective generation of dTuD miRNA inhibitor, providing a powerful tool for efficient miRNA suppression in vitro and in vivo.     

Assessment of rhizosphere processes for removing water-borne macrolide antibiotics in constructed wetlands

Plant and Soil - Limited information is available on plant rhizosphere processes for removing antibiotics in antibiotic-contaminated waters. This study identifies rhizosphere processes and...     

Induction of specific human primary immune responses to a Semliki Forest virus–based tumor vaccine in a Trimera mouse model

Recombinant Semliki Forest virus (rSFV) enables high-level, transient expression of heterologous proteins in vivo, and is believed to be a superior vector for genetic vaccination, compared with the conventional DNA plasmid. Nonetheless, the efficacy of rSFV-based vaccine in eliciting human immune responses has not been tested. We used a Trimera mouse model, consisting of lethally irradiated BALB/c host reconstituted with nonobese diabetes/severe combined immunodeficiency (NOD/SCID) bone marrow plus human peripheral blood mononuclear cells (PBMCs), to characterize the in vivo immune responses against rSFV-encoded human melanoma antigen MAGE-3. MAGE-3–specific antibody and cytotoxic T lymphocyte (CTL) activity were detected by ELISA and ⁵¹Cr-release assay, respectively, and the responses were compared with those induced by a plasmid DNA vaccine encoding the same antigen. The results showed that rSFV vaccine could elicit human MAGE-3–specific antibody and CTL response in the Trimera mice, and the antitumor responses were more potent than those by plasmid DNA vaccination. This is the first report to evaluate human immune responses to an rSFV-based tumor vaccine in the Trimera mouse model. Our data suggest that rSFV vector is better than DNA plasmid in inducing protective immunity, and the Trimera model may serve as a general tool to evaluate the efficacy of tumor vaccines in eliciting human primary immune response in vivo.     

Fluid-Phase Markers in the Basolateral Endocytic Pathway Accumulate in Response to the Actin Assembly-promoting Drug Jasplakinolide

To investigate the role of filamentous actin in the endocytic pathway, we used the cell-permeant drug Jasplakinolide (JAS) to polymerize actin in intact polarized Madin–Darby canine kidney (MDCK) cells. The uptake and accumulation of the fluid-phase markers fluorescein isothiocyanate (FITC)-dextran and horseradish peroxidase (HRP) were followed in JAS-treated or untreated cells with confocal fluorescence microscopy, biochemical assays, and electron microscopy. Pretreatment with JAS increased the uptake and accumulation of fluid-phase markers in MDCK cells. JAS increased endocytosis in a polarized manner, with a marked effect on fluid-phase uptake from the basolateral surface but not from the apical surface of polarized MDCK cells. The early uptake of FITC-dextran and HRP was increased more than twofold in JAS-treated cells. At later times, FITC-dextran and HRP accumulated in clustered endosomes in the basal and middle regions of JAS-treated cells. The large accumulated endosomes were similar to late endosomes but they were not colabeled for other late endosome markers, such as rab7 or mannose-6-phosphate receptor. JAS altered transport in the endocytic pathway at a later stage than the microtubule-dependent step affected by nocodazole. JAS also had a notable effect on cell morphology, inducing membrane bunching at the apical pole of MDCK cells. Although other studies have implicated actin in endocytosis at the apical cell surface, our results provide novel evidence that filamentous actin is also involved in the endocytosis of fluid-phase markers from the basolateral membrane of polarized cells.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.