Expression of Multiple Resistance Genes Enhances Tolerance to Environmental Stressors in Transgenic Poplar (Populus × euramericana ‘Guariento’)

Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana ‘Guariento’) harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional research is needed to fully understand the relationships between the altered phenotypes and the function of each transgene in multigene transformants

SN2' alkylation of chiral allylic cyanohydrin o-phosphates with organocuprates

Enantiomerically enriched cyanohydrin O-phosphates, prepared by enantioselective cyanophosphorylation of α,β-unsaturated aldehydes, react regioselectively at the γ-position with organocuprates derived from alkyl Grignard reagents and CuCN to afford chiral γ-alkyl-substituted α,β-unsaturated nitriles. The configuration of the new C–C double bond is mainly (E) when the reaction is performed at –78 °C and (Z) when it is carried out at higher temperatures (0 °C). A high level of transfer of the chirality in the new stereocentre, corresponding to a stereospecific anti attack onto the cyanophosphate, is observed. Enantiomerically enriched (E)-γ-alkylated α,β-unsaturated esters are prepared after subsequent methanolysis in a three-step sequence from the corresponding α,β-unsaturated aldehydes. In addition, the synthesis of (R)-4-methylnonan-1-ol, also known as the sex pheromone of the yellow mealworm Tenebrio molitor L, and its (S) enantiomer have been carried out in a four-step route from (E)-oct-2-enal.This work has been supported by the DGES of the Spanish Ministerio de Educación y Ciencia (MEC) (CTQ2004-00808/BQU), the Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134 and GV05/144) and the University of Alicante

TGF-β Controls the Formation of Kidney-Resident T Cells via Promoting Effector T Cell Extravasation

Abstract Tissue-resident memory T (TRM) cells, a population of noncirculating memory T cells, are one of the essential components of immunological memory in both mouse and human. Although CD69+CD103+ TRM cells represent a major TRM cell population in barrier tissues including the mucosal surface and the skin, CD69+CD103− TRM cells dominate most nonbarrier tissues, such as the kidney. TGF-β is required for the differentiation of CD69+CD103+ TRM cells in barrier tissues. However, the developmental control of CD69+CD103− TRM cells in nonbarrier tissues remains largely unknown and the involvement of TGF-β signaling is less clear. In this study we demonstrated that TGF-β promoted the formation of kidney-resident T cells via enhancing the tissue entry of effector T cells. Mechanistically, TGF-β enhanced E- and P-selectin and inflammatory chemokine-mediated extravasation of effector T cells. Thus TGF-β controls the first developmental checkpoint of TRM cell differentiation in nonbarrier tissues.</jats:p

Effect of TGF-β on Antigen-specific CD8+ T cell Response in Colitis

Abstract Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract primarily including Crohn’s Disease (CD) and Ulcerative Colitis (UC). IBD affects 1.6 million Americans, and the worldwide incidence of IBD is growing in areas where the disease was previously infrequent. Currently, genetics, intestinal microbiota, environment, and dysregulation of the intestinal immune response are thought to be responsible for the development of IBD. Increased understanding of the immune response in IBD can be used to develop and improve treatments for patients. Much work has been done on the role of CD4+ T helper cells in IBD. The role of CD8+ T cells has been less heavily investigated despite noted differences in CD8+ T cells between UC and CD patients and healthy subjects. In order to follow antigen-specific CD8+ T cell response during IBD, we developed a mouse strain in which the expression of model antigen Ova was specifically induced in the large intestine epithelium upon tamoxifen treatment (i.e. CDX2-cre/ERT2 Rosa26-Ova mice). By examining adoptively transferred OT-1 T cells, large intestine-specific CD8+ T cell response was determined during DSS induced colitis. Interestingly, the response of control OT-1 T cells was largely restricted to the large intestine while TGF-β unresponsive OT-1 T cells underwent dramatic expansion at both gut-associated and systemic sites. The functional consequence of TGF-β-controlled expansion of CD8+ T cells in colitis is currently under investigation.</jats:p

Impact of Skull Thickness on Cerebral NIRS Oximetry in Neonates: An in silico Study

Monitoring of cerebral tissue oxygen saturation (StO2) by near-infrared spectroscopy (NIRS oximetry) has great potential to reduce the incidence of hypoxic and hyperoxic events and thus prevent long-term disabilities in preterm neonates. Since the light has to penetrate superficial layers (bone, skin and cerebrospinal fluid) before it reaches the brain, the question arises whether these layers influence cerebral StO2 measurement. We assessed this influence on the accuracy of cerebral StO2 values. For that purpose, we simulated light propagation with ‘N-layered medium’ software. It was found that with a superficial layer thickness of ≤6 mm, typical for term and preterm neonates, StO2 accurately reflects cerebral tissue oxygenation