Dual Mechanism of Interleukin-3 Receptor Blockade by an Anti-Cancer Antibody

SummaryInterleukin-3 (IL-3) is an activated T cell product that bridges innate and adaptive immunity and contributes to several immunopathologies. Here, we report the crystal structure of the IL-3 receptor α chain (IL3Rα) in complex with the anti-leukemia antibody CSL362 that reveals the N-terminal domain (NTD), a domain also present in the granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-5, and IL-13 receptors, adopting unique “open” and classical “closed” conformations. Although extensive mutational analyses of the NTD epitope of CSL362 show minor overlap with the IL-3 binding site, CSL362 only inhibits IL-3 binding to the closed conformation, indicating alternative mechanisms for blocking IL-3 signaling. Significantly, whereas “open-like” IL3Rα mutants can simultaneously bind IL-3 and CSL362, CSL362 still prevents the assembly of a higher-order IL-3 receptor-signaling complex. The discovery of open forms of cytokine receptors provides the framework for development of potent antibodies that can achieve a “double hit” cytokine receptor blockade

Ontogeny and thermogenic role for sternal fat in female sheep

Brown adipose tissue acting through a unique uncoupling protein (UCP1) has a critical role in preventing hypothermia in new-born sheep but is then considered to rapidly disappear during postnatal life. The extent to which the anatomical location of fat influences postnatal development and thermogenic function, particularly following feeding, in adulthood, are not known and were both examined in our study. Changes in gene expression of functionally important pathways (i.e. thermogenesis, development, adipogenesis and metabolism) were compared between sternal and retroperitoneal fat depots together with a representative skeletal muscle over the first month of postnatal life, coincident with the loss of brown fat and accumulation of white fat. In adult sheep, implanted temperature probes were used to characterise the thermogenic response of fat and muscle to feeding and the effects of reduced or increased adiposity. UCP1 was more abundant within sternal than retroperitoneal fat and was only retained in the sternal depot of adults. Distinct differences in the abundance of gene pathway markers were apparent between tissues, with sternal fat exhibiting some similarities with muscle that were not apparent in the retroperitoneal depot. In adults, the post-prandial rise in temperature was greater and more prolonged in sternal than retroperitoneal fat and muscle, a difference that was maintained with altered adiposity. In conclusion, sternal adipose tissue retains UCP1 into adulthood when it shows a greater thermogenic response to feeding than muscle and retroperitoneal fat. Sternal fat may be more amenable to targeted interventions that promote thermogenesis in large mammals

Investigations using chiral scandium (III) Lewis acids

Lewis acidic chiral scandium(III) catalysts have been developed and tested with a range of bidentate substrates in both Diels-Alder and aza-Michael reactions. Scandium(III) complexes incorporating bipybox, phenbox (a new class oftetradentate chiral ligand) and pybox ligands, have been found to give significant enantioselectivity in reactions involving 3-acyloxazolidinones and 3-formylpyrone- containing substrates. Molecular modelling has been used to understand more about the action of these catalysts and to design new ligands which can lead to higher levels of enantioselectivity in these reactions. For acyloxazolidinone-containing substrates it was found that scandium(III)/pybox catalysts gave the same sense of stereocontrol in both Diels-Alder and aza-Michael reactions. It was observed that the sense of enantiocontrol with a particular class of ligand was determined by the stereochemistry of the R -substituent on the ligand and the degree of this stereocontrol was influenced by its size. These observations have lead to a proposal of how the substrates bind to the chiral scandium(III) catalysts for each ligand type and how the enantioselectivity of the products is derived. The chiral scandium(III) Lewis acid catalysts were also used to promote an endo- selective intramolecular Diels-Alder reaction of a 3-formylpyrone-containing substrate, the key step in a synthesis of solanapyrone D. This natural product was prepared in up to 77 % ee with all four contiguous formed in this final step of the synthesis. The highest levels of enantioselectivity for this reaction were given by scandium(III)-pybox catalysts. A greater understanding of chiral scandium(III) catalysts, particularly the substrate- catalyst interactions, has been gained in this thesis and can hopefully be used in the future to aid further development of asymmetric catalysis with scandium(III). 11.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Performance of bitumen treated base (BTB) pavement

Two major factors that compromise the integrity of a road pavement are excess moisture and heavy axle traffic. The inundation of recent flooding event on Queensland road infrastructures damaged much of the road network infrastructures. The Department of Transport and Main Roads is currently searching for alternative sustainable pavements for the re-construction of approximately 1,450 kilometers of damaged roads caused by the flooding. The aim of this paper is to present the short term performance monitoring conducted on Trial Bitumen Treated Base (BTB) pavement sections constructed on the Warrego Highway Roma as a possible solution to increasing the integrity of pavement structure. Currently there is no published standard specification for Bitumen Treated Base as a pavement rehabilitation option in Australia. Previous performances of the BTB pavement in the Mackay Regional Council were shown to be better than the original pavements in each of the locations. For the current investigation six trial sections 200m long were constructed with full depth BTB pavement replacement and resurfacing. The BTB pavement structure consisted of 7mm C320 armour coat seal, BTB total layer thickness ranging from 265mm to 330mm and stabilized subgrade. Post construction performance indicators were monitored after a period of 7 days, 3 months and 6 months. two laser profilometer was used to evaluate the surface roughness and the falling weight deflectometer used for the determination of the pavement modulus

Mouse H-2(k)-restricted cytotoxic T cells recognize antigenic determinants in both the HA1 and HA2 subunits of the influenza A/PR/8/34 hemagglutinin

We have constructed two chimeric influenza hemagglutinin (HA) genes in which the HA1 and HA2 subunits of the HA molecule have been interchanged between influenza A/PR/8/34 (H1 subtype) and A/NT/60/68 (H3 subtype). These genes were used to construct recombinant vaccinia viruses that expressed intact chimeric HA. These recombinant viruses were used to test whether murine CTL recognize antigenic determinants in either the HA1, HA2, or both subunits. We found that both subunits of the HA molecule contain determinants for CTL. This implies that CTL have, at least in part, separate antigenic determinants from B lymphocytes, which recognize mainly epitopes within the HA1 subunit