bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting of immunostimulatory DNA cures experimental visceral leishmaniasis through nitric oxide up‐regulation and T cell activation
Authors: Datta Neeta , Mukherjee Snigdha , Das Lopamudra , Das Pijush K. 
Published: May 2003

AbstractActive targeting of CpG‐containing oligodeoxynucleotide (CpG‐ODN) to macrophages was studied by incorporating it in mannose‐coated liposomes, using visceral leishmaniasis as the model macrophage disease. Mannosylated liposomal CpG‐ODN was more effective than liposomal or free CpG‐ODN in inhibiting amastigote multiplication within macrophages. Moreover, in a 60‐day mouse model of visceralleishmaniasis, complete elimination of spleen parasite burden was achieved by mannosylated liposomal CpG‐ODN, compared to 62% and 81% parasite suppression by free and liposomal ODN, respectively, at a similar dose. Although in vitro exposure of CpG‐ODN did not induce marked nitric oxide (NO) generation by macrophages, considerably enhanced amount of NO was generated by macrophages ofCpG‐ODN‐treated animals. Their splenocytes secreted soluble factors required for the induction of NO generation, and the increased NO generation was paralleled by an increase in antileishmanial activity. Inducible NO generation was suppressed by treating splenocyte supernatants with anti‐IFN‐γ or anti‐IL‐12 antibodies, whereas in vivo administration of these anti‐cytokine Ab along with CpG‐ODN reversed protection against infection. CpG‐ODN treatment resulted in reduced levels of IL‐4, but increased levels of IFN‐γ, IL‐12 and inducible NO synthase in infected spleen cells, which was magnified by encapsulation in mannose‐coated liposomes. This targeted treatment was not only curative, but it also imparted resistance to reinfection. These results represent a general approach for intracellular targeting of CpG‐ODN, which effectively enhances its therapeutic potential in redirecting curative Th1 responses in Th2‐driven disorders.
Heat shock factor 1‐independent activation of dendritic cells by heat shock: implication for the uncoupling of heat‐mediated immunoregulation from the heat shock response
Authors: Zheng Hong , Benjamin Ivor J , Basu Sreyashi , Li Zihai 
Published: May 2003

AbstractThe induction of heat shock proteins by heat shock is classically defined as the heat shock response, which is involved in cytoprotection, inflammation and immune responses. Whereas the cytoprotective properties of heat shock have been well characterized, the immunomodulating roles of the heat shock response on the immune system are just emerging. In particular, it is not known whether immunomodulating functions of heat are mediated by the heat shock response. We addressed this question genetically, using a murine model that is unable to mount the heat shock response because of deletion of a major transcriptional factor, heat shock factor 1 (Hsf1). We focused on the roles of heat shock on modulating the functions of dendritic cells (DC) because of their important roles in both innate and adaptive immunity. We found that heat shock matures CD11c+ DC both in vitro and in vivo, phenotypically and functionally, in the absence of any exogenous inflammatory stimuli. Furthermore, heat‐shock‐mediated DC maturation is independent of Hsf1, as Hsf1–/– DC can be matured by heat shock equally well as wild‐type DC. Our novel findings demonstrate that heat shock, one of the most primitive biological responses, can modulate the immune response without the requirement for the transcriptional induction/repression of target genes mediated by Hsf1.
Selective absence of CD8+ TCRα β+ intestinal epithelial cells in transgenic mice expressing β2‐microglobulin‐associated ligands exclusively on thymic cortical epithelium
Authors: Capone Myriam , Lees Rosemary K. , Finke Daniela , Ernst Bettina , Meerwijk Joost P. M. Van , MacDonald H. Robson 
Published: May 2003

AbstractWhereas interactions between the TCRα β and self MHC:peptide complexes are clearly required for positive selection of mature CD4+ and CD8+ T cells during intrathymic development, the role of self or foreign ligands in maintaining the peripheral T cell repertoire is still controversial. In this report we have utilized keratin 14‐β2‐microglobulin (K14‐β2m)‐transgenic mice expressing β2m‐associated ligands exclusively on thymic cortical epithelial cells to address the possible influence of TCR:ligand interactions in peripheral CD8+ T cellhomeostasis. Our data indicate that CD8+ T cells in peripheral lymphoid tissues are present in normal numbers in the absence of self MHC class I:peptide ligands. Surprisingly, however, steady state homeostasis of CD8+ T cells in the intestinal epithelium is severely affected by the absence of β2m‐associated ligands. Indeed TCRα β+ IEL subsets expressing CD8α β or CD8α α are both dramatically reduced in K14‐β2m mice, suggesting that the development, survival or expansion of CD8+ IEL depends upon interaction of the TCR with MHC class I:peptide or other β2m‐associated ligands elsewhere than on thymic cortical epithelium. Collectively, our data reveal an unexpected difference in the regulation of CD8+ T cell homeostasis by β2m‐associated ligands in the intestine as compared to peripheral lymphoid organs.
Rational design of new CpG oligonucleotides that combine B cell activation with high IFN‐α induction in plasmacytoid dendritic cells
Authors: Hartmann Gunther , Battiany Julia , Poeck Hendrik , Wagner Moritz , Kerkmann Miren , Lubenow Norbert , Rothenfusser Simon , Endres Stefan 
Published: May 2003

AbstractTwo different types of CpG motif‐containing oligonucleotides (CpG ODN) have been described: CpG‐A with high induction of IFN‐α in plasmacytoid dendritic cells; and CpG‐B with little induction of IFN‐α, but potent activation of B cells. In this study, we demonstrate that CpG‐A fail to activate B cells unless plasmacytoid dendritic cells are present. We identified a new set of CpG ODN sequences which induces high levels of IFN‐α in plasmacytoid dendritic cells but remains capable of directly activating B cells. These new CpG ODN (termed CpG‐C) are more potent stimulants of B cells than CpG‐B due to their ability of directly and indirectly (via plasmacytoid dendritic cells) activating B cells. The sequence of CpG‐C combines structural elements of both CpG‐A and CpG‐B. The most potent sequence, M362, contains a 5′‐end ‘TCGTCG‐motif’ and a ‘GTCGTT‐motif’, both of which are present in CpG‐B (ODN 2006); a palindromic sequence characteristic for CpG‐A (ODN 2216); but no poly G motif required for CpG‐A. In conclusion, we defined the first CpG‐containing sequences that potently activate both TLR9‐expressing immune cell subsets in humans, the plasmacytoid dendritic cell and the B cell. CpG‐C may allow for improved therapeutic immuno‐modulation in vivo.
Role of Toll‐like receptors in costimulating cytotoxic T cell responses
Authors: Schwarz Katrin , Storni Tazio , Manolova Vania , Didierlaurent Arnaud , Sirard Jean‐Claude , Röthlisberger Peter , Bachmann Martin F. 
Published: May 2003

AbstractStimulation of Toll‐like receptors (TLR) by pathogen‐derived compounds leads to activation of APC, facilitating the induction of protective immunity. This phenomenon is the basis of most adjuvant formulations currently in development. Here, we tested the ability of TLR2, 3, 4, 5, 7 and 9 signaling to enhance CTL responses upon vaccination with virus‐like particles. Stimulation of TLR2 and 4 failed to increase CTL responses, whereas ligands for TLR3, 5 and 7 exhibited moderate adjuvant function. In contrast, stimulation of TLR9 dramatically increased CTL responses, indicating that ligands for TLR9 are likely to be the most promising candidates for the development of novel adjuvant formulations for stimulating CTL responses.
The natural killer cell‐mediated killing of autologous dendritic cells is confined to a cell subset expressing CD94/NKG2A, but lacking inhibitory killer Ig‐like receptors
Authors: Chiesa Mariella Della , Vitale Massimo , Carlomagno Simona , Ferlazzo Guido , Moretta Lorenzo , Moretta Alessandro 
Published: May 2003

AbstractThe cognate NK–DC interaction in inflamed tissues results in NK cell activation and acquisition of cytotoxicity against immature DC (iDC). This may represent a mechanism of DC selection required for the control of downstream adaptive immune responses. Here we show that killing of monocyte‐derived iDC is confined to the NK cell subset that expresses CD94/NKG2A, but not killer Ig‐like receptors (KIR). Consistent with these data, the expression of HLA‐E (i.e. the cellular ligand of CD94/NKG2A) was down‐regulated in iDC. On the other hand, HLA‐B and HLA‐C down‐regulation in iDC was not sufficient to induce cytotoxicity in NK cells expressing KIR3DL1 or KIR2DL. Remarkably, CD94/NKG2A+KIR– NK cells were heterogeneous in their ability to kill iDC and an inverse correlation existed between their CD94/NKG2A surface density and the magnitude of their cytolytic activity. It is conceivable that the reduced CD94/NKG2A surface density enables these cells to efficiently sense the decrease of HLA‐E surface expression in iDC. Finally, most NK cells that lysed iDC did not kill mature DC that express higher amounts of HLA class I molecules (including HLA‐E)as compared with iDC. However, a small NK cell subset was capable of killing not only iDC but also mature DC.
XAS, ESR and Potentiometric Studies of Three DinuclearN,N′‐para‐Xylylenebis(tetraazamacrocycle)copper(II) Complexes − X‐ray Crystal Structure of [N,N′‐p‐Xylylenebis(cyclen)]copper(II)
Authors: Soibinet Mathieu , Déchamps‐Olivier Isabelle , Guillon Emmanuel , Barbier Jean‐Pierre , Aplincourt Michel , Chuburu Françoise , Le Baccon Michel , Handel Henri 
Published: May 2003

AbstractDicopper complexes withN,N′‐p‐xylylenebis(cyclam or cyclen) and with the heteroditopicN,N′‐p‐xylylenebis(cyclam‐cyclen) were synthesized. An X‐ray study of theN,N′‐p‐xylylenebis(cyclen)dicopper complex showed that the copper(II) ion is five‐coordinate with an H2O molecule in apical position. With this ligand, a polymeric chain was also obtained in the presence of KSCN. The terminal donor atoms of the bridging NCS−anion are coordinated in apical position to the square‐pyramidal copper(II) ion. Two alternating kinds of Cu2L4+moieties are present in the chain, the first with two N4S chromophores and the second with two N5chromophores. EXAFS and XANES results are in agreement with a five‐coordinate copper ion in the cyclen unit and a six‐coordinate copper ion in the cyclam unit. Thermodynamic constants were determined by potentiometry. The existence of dinuclear Cu2L4+species (ligand/metal ratio < 1) and mononuclear CuLHn(2+n)+species (ligand/metal ratio > 1) were confirmed by an ESR study at variable pH. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of [RuX(CO){η2‐C,N‐C6H4C(H)=NC6H4‐4‐NO2}(PPh3)2] (X = F, Cl, Br, I): Evidence of Non‐Conventional Ru−X Hydrogen Bonds Leading to Octahedral Coordination at the Halide Atom
Authors: Flower Kevin R. , Pritchard Robin G. , Warren John E. 
Published: May 2003

AbstractTreatment of [RuCl(CO){η2‐C,N‐C6H4C(H)=NC6H4‐4‐NO2}(PPh3)2] (4‐Cl) with Ag[BF4] in acetone/CH2Cl2 gives the cationic complex [Ru{O=C(CH3)2}(CO){η2‐C,N‐C6H4C(H)=NC6H4‐4‐NO2}(PPh3)2][BF4] (not isolated), which then reacts with NaX (X = F, Br, I) to afford the new compounds [RuX(CO){η2‐C,N‐C6H4C(H)=NC6H4‐4‐NO2}(PPh3)2] (X = F, Br, I) (4‐F, 4‐Br, and 4‐I). All of the new compounds have been characterised by elemental analysis (C, H, and N), 1H, 13C{1H}, 31P{1H} NMR spectroscopy and IR spectroscopy. The IR data support the hypothesis that the fluoride ligand is the strongest halogen π‐donor to the metal centre. In addition, the compounds 4‐Br·1.5CHCl3, 4‐Cl·1.5CHCl3, 4‐F·2CDCl3, and 4‐I·1.5CHCl3 have been characterised by single‐crystal X‐ray diffraction studies; all show Ru−X···HCCl3 interactions with the Ru−F interaction being the strongest. In addition, there is evidence for the presence of competing RuX···ClCHCl2 (X = Cl, Br) interactions in compounds 4‐Br and 4‐Cl; these appear to be charge transfer in nature. The generality of these interactions has been probed using searches of the Cambridge Crystallographic Database and the data obtained suggests that these interactions have some, but limited, precedence. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactivity of Metallophosphide Anions with Electrophilic (Arene)tricarbonylmetal Complexes
Authors: Comte Virginie , Tranchier Jean Philippe , Rose‐Munch Françoise , Rose Eric , Perrey Danièle , Richard Philippe , Moïse Claude 
Published: May 2003

AbstractReaction of metallophosphide anions [(CO)xM′PPh2]− (M′ = Cr, Fe) with neutral tricarbonyl(η6‐fluoroarene)chromium and cationic (η6‐arene)tricarbonylmanganese complexes give rise to the formation of dinuclear complexes. These complexes are obtained either by substitution of the fluoride anion in the (arene)chromium complexes, or by addition to the ring in the (arene)manganese complexes. The X‐ray structure of one homodimetallic (Cr−Cr) complex was obtained and compared with its solution structure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Rigid Molecular Scaffold Affixing a (Polypyridine)ruthenium(II)‐ and a Nickel(II)‐Containing Complex: Spectroscopic Evidence for a Weakly Coupled Bichromophoric System
Authors: Pellegrin Yann , Berg Katja E. , Blondin Geneviève , Anxolabéhère‐Mallart Elodie , Leibl Winfried , Aukauloo Ally 
Published: May 2003

AbstractThe synthesis of DppztBuSalH2 (7), a rigid conjugated ditopic ligand containing a Dppz (dipyrido[3,2‐a:2′,3′‐c]phenazine) skeleton and a salophen‐type chelate, is reported. The complexes DppztBuSalNi (10), [Ru(bpy)2(DppztBuSalH2)]2+ (11), and [Ru(bpy)2(DppztBuSalNi)]2+ (12) have been prepared and characterised using common spectroscopic methods. Electrochemical, UV/Vis spectroelectrochemical and EPR studies were conducted on compounds 7, 10, 11, and 12. The singly reduced radical forms of 7 and 10 can be generated electrochemically, with the lone electron located on the low‐lying phenazine π*‐molecular orbital. Complexes 11 and 12 show several reduction waves and electronic and EPR data obtained for the electrogenerated singly reduced species show them to be closely related to the radical species 7·− and 10·−, respectively. The presence of nickel(II) in compound 12 renders the addition of the second electron on the phenazine group reversible. Both 11 and 12 show common features on the cathodic side of their cyclic voltammograms, with reversible one‐electron ruthenium‐centred oxidation. An additional low‐potential reversible‐oxidation wave is observed for 12, and this is ascribed to oxidation of the nickel(II) ion. The combined spectroscopic data best describe the ruthenium‐containing complexes as weakly coupled bichromophoric systems. Photophysical studies attest to the formation of a charge‐separated state for 11, whereas a strong quenching is detected for 12. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Coordination Modes in a (Thiosemicarbazone)copper(II)/Oxalato System − Structures of [{Cu(L)}2(ox)]·2H2O, [Cu(HL)(ox)(H2O)], [{Cu(HL)}2(ox)][Cu(ox)2]·2H2O and [{Cu(HL)}2(ox)](NO3)2 − Ferro‐ vs. Antiferromagnetic Behavior in Dinuclear Compounds
Authors: Gómez‐Saiz Patricia , García‐Tojal Javier , Maestro Miguel , Mahía José , Lezama Luis , Rojo Teófilo 
Published: May 2003

AbstractComplexes with the formula [{Cu(L)}2(ox)]·2H2O (1), [Cu(HL)(ox)(H2O)] (2), [{Cu(HL)}2(ox)][Cu(ox)2]·2H2O (3) and [{Cu(HL)}2(ox)](NO3)2 (4) (HL = C7H8N4S, pyridine‐2‐carbaldehyde thiosemicarbazone) have been synthesized from Cu(L)(NO3) and oxalic acid while modulating the stoichiometries and the pH of the media. Single crystal X‐ray diffraction studies show that the structures of 1 and 4 contain dinuclear entities with distorted square pyramidal copper(II) ions. The dinuclear complexes are centrosymmetric in 1 and non‐centrosymmetric in 4. The metal centers are coordinated to the NNS atoms from the tridentate thiosemicarbazone ligand and to two oxygen atoms from the oxalato coligand. The latter ligand exhibits tetradentate behavior and acts as a bridge between the copper(II) ions. The thiosemicarbazone ligand is either present in the anionic (1) or the neutral (4) form. Compound 2 is composed of monomeric species containing square pyramidal copper(II) ions that are coordinated to the thiosemicarbazone ligand, one water molecule and one monodentate oxalato coligand. It is important to note that the oxalato is highly twisted in this complex, the O(1)−C(8)−C(9)−O(3) dihedral angle between the carboxylate groups is 79.9(4)°. Compound 3 contains both the dinuclear cationic species, analogous to those described for compound 4, and square planar (bisoxalato)copper(II) anions. Strong hydrogen bonds and π‐π stacking are present in these complexes. Structural and spectroscopic results suggest the presence of relevant ligand‐to‐metal charge transfers in these compounds. The EPR spectra of 1, 2 and 4 exhibit rhombic symmetry. Magnetic measurements on 1 and 4 show antiferromagnetic and ferromagnetic coupling, respectively. The susceptibility data were fitted to the Bleaney−Bowers equation for copper(II) dinuclear complexes. The J/k values obtained are −6.20 and +7.73 K for compounds 1 and 4, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Crystal Structures and Intercalation Reactions of Three‐Dimensional Coordination Polymers [M(H2O)2]2[Mo(CN)8]·4H2O (M = Co, Mn)
Authors: Willemin Stéphanie , Larionova Joulia , Clérac Rodolphe , Donnadieu Bruno , Henner Bernard , Le Goff Xavier Fréderic , Guérin Christian 
Published: May 2003

AbstractTwo coordination polymers [MII(H2O)2]2[MoIV(CN)8]·4H2O [MII = Co (1), Mn (2)] were prepared as monocrystals and structurally characterised. These compounds crystallise in the tetragonal systems I4/m (1) and I4/mcm (2) and form three‐dimensional networks containing channels occupied by two types of water molecules, i.e. coordinated to MII and crystallised ones. The dehydration of these materials occurs topochemically to give [MII(H2O)]2[MoIV(CN)8] compounds having an open metal coordination site on the MII ions that may be accessible to coordination by other species and serve as a reaction site. The intercalation of water, ammonia and amines has been studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structural, Magnetochemical and Electrochemical Studies of Dinuclear Complexes Containing the [VVO]2, [VIVO]2, CrIII2, MnIII2 and FeIII2 Cores of a Potentially Pentadentate Phenol‐Containing Ligand with (O,N,O,N,O)‐Donor Atoms
Authors: Mukherjee Soumen , Weyhermüller Thomas , Bothe Eberhard , Chaudhuri Phalguni 
Published: May 2003

AbstractDinuclear complexes [L2FeIII2] (1), [L2MnIII2] (2a), [L2MnIII2(THF)2] (2b), [L2CrIII2] (3), [L(VIVO)2(OCHMe2)] (4) and [L2(VVO)2] (5) with a pentadentate phenol‐containing ligand H3L (= C6H2(CH3)(OH){[C(CH3)3]2(OH)NCH}2) bearing the N2O3 donor atoms have been synthesized and the X‐ray structures of 1, 2b, 4 and 5 are reported. The compounds were characterized by IR, UV/Vis and Mössbauer spectroscopy, mass spectrometry, electrochemical and variable‐temperature (2−295 K) magnetic susceptibility measurements. Analysis of the susceptibility data demonstrates antiferromagnetic interactions between the metal centers establishing diamagnetic ground states for complexes 1−4. The electrochemical results suggest the generation of ligand‐centered oxidation processes attributable to the phenoxyl radicals, rather than the formation of unusually high oxidation states at the central metal centers. The ligand H3L has the potential to act in a multidentate fashion as evidenced by the X‐ray structures of 2b and 5. In compound 2b the central phenolate oxygen of the p‐cresol ring does not function as a bridging atom between two manganese centers, whereas in 5 the ligand is tetradentate with one noncoordinating nitrogen atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Preparation, Reactivity and Peptide Labelling Properties of (η6‐Arene)ruthenium(II) Complexes with Pendant Carboxylate Groups
Authors: Stodt Ralf , Gencaslan Susan , Müller Iris M. , Sheldrick William S. 
Published: May 2003

Abstract(η6‐Arene)ruthenium(II) complexes of the type [{[η6‐C6H5(CH2)nCOOH]Ru(µ‐Cl)Cl}2] (2a, n = 1; 3, n = 3) with tethered carboxylate groups can be obtained by dehydrogenation of the appropriate cyclohexadiene with RuCl3·3H2O. Formation of a κO‐coordinated chelate in weakly acidic solution is observed by means of a 1H NMR titration for both [{η6‐C6H5(CH2)3COOH}Ru(aq)](OTf)2 (3a′) and [{η6‐C6H5(CH2)3COOH}Ru(phen)(aq)](OTf)2 (5′). Sandwich complexes of the type [{η6‐C6H5(CH2)3COOH}Ru(η6‐amino acid)](OTf)2 [amino acid = AcpheOH (6), ActyrOEt (7), ActrpOH (8)] can be prepared by treating [{η6‐C6H5(CH2)3COOH}Ru(acetone)3](OTf)2 with the appropriate aromatic bioligand in CF3COOH (6/8) or CH2Cl2 (7). Chemospecific η6‐labelling of the C‐terminal indole function is observed for the peptide HphetrpOH in the analogous complex 9. Quantitative formation of 8 can also be achieved in aqueous solution in the presence of a 3:1 excess of the {η6‐C6H5(CH2)3COOH}RuII fragment. This can also be employed for the N‐terminal labelling of amino acids and peptides in its sandwich complex [(η6‐C6Me6)Ru{η6‐C6H5(CH2)3COOH}](OTf)2 (10). Coupling reactions by the carbodiimide method with EDC afford water‐stable complexes of the type [(η6‐C6Me6)Ru{η6‐C6H5(CH2)3C(O)R}](OTf)2 [R = trpOMe (11), pheOMe (12), glyglyOEt (13)] in good yields. X‐ray structures of [(η6‐C6H5CH2COOC2H5)RuCl(phen)](OTf) (4b′) and 10 are reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Kinetic and Equilibrium Studies of Reactions of N‐Heterocycles with Dimeric and Monomeric Oxorhenium(V) Complexes
Authors: Espenson James H. , Nabavizadeh S. Masoud 
Published: May 2003

AbstractEquilibrium constants have been evaluated for the reaction {MeReO(edt)}2 + 2 L ⇄ 2 MeReO(edt)L, where edt is 1,2‐ethanedithiolate and L is any of 13 N‐donor heterocyclic ligands. The values of K range from 1.37(27)×10−2 for pyrimidine to 1.95(6)×106 for imidazole at 25 °C in chloroform. A successful correlation of logK with log (Ka) of HL+ was realized except in the case of the 2‐substituted ligands 2‐picoline and quinoline, where steric effects make K smaller than expected from the proton basicity of L. The kinetics of the same reactions were studied; the rate law for the reaction in the forward direction is given by −d[{MeReO(edt)}2]/dt = {ka + kb[L]}[L] × [{MeReO(edt)}2]. Except for 2‐picoline and quinoline, the major pathway is provided by the term that shows the quadratic dependence on [L]. Values of log (kb) also correlate with log K, and therefore necessarily with log (Ka).