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A series of macrocyclic tetraazacrown ethers containing two pyridine, quinoline, 8-hydroxyquinoline, or 8-aminoquinoline sidearms has been prepared. Crab-like cyclization of bis(alpha-chloroacetamide)s and diamines followed by reduction of the cyclic diamides was used to synthesize the selected crown ethers containing two unsubstituted macroring nitrogen atoms. The preparation of the macrocycles with sidearms was accomplished by reductive amination of the proper aldehydes with the crown ethers using sodium triacetoxyborohydride (NaBH(OAc)(3)) as the reducing agent. The 8-hydroxyquinoline- and 8-aminoquinoline-containing macrocycles were synthesized by reductive amination of 8-acetoxyquinoline-2-carboxaldehyde or 8-nitroquinoline-2-carboxaldehyde followed by removing the acetate groups or reducing the nitro groups to amino groups, respectively. Complexation of ligand 22 with Cu(2+), Co(2+), Ni(2+), Zn(2+), Cd(2+), and Pb(2+) was evaluated potentiometrically in aqueous solution (0.10 M Me(4)NCl) at 25 degrees C. Ligand 22 formed very stable complexes with these metal ions. The UV-vis spectra of 22 and its complexes were examined in an aqueous acetic acid buffer solution (pH 5). The 22-Cu(2+) complex provided a new absorption band at 258 nm.

Attachment of amino acids to cholic acid derivatives yielded compounds that sensitize Gram-negative bacteria to hydrophobic antibiotics. Incorporation of three amino acid onto a cholic acid derivative via ester bonds was only achieved with non-α-branched amino acids. Three non-α-branched or three α-branched amino acids were coupled to the steroid backbone via amide bonds.

Reduction of the trioxime derivative of dehydrocholic acid methyl ester with NaBH4TiCl4 yielded triamine-derivatives of cholic acid. The major product from the reduction was the 3α, 7α, 12α diastereomer. Stereochemistry of the reduction products was determined via NMR spectroscopy and X-ray crystallography.

Cholic acid derivatives appended with amine groups have been prepared for use as permeabilizers of the outer membranes of Gram-negative bacteria. These compounds interact synergistically with antibiotics such as erythromycin and novobiocin to inhibit growth of Gram-negative bacteria. When a hydrophobic chain is included on the permeabilizers, they can be converted into potent antibiotics. The role of the hydrophobic chain is to facilitate self-promoted transport of the cholic acid derivatives across the outer membrane of Gram-negative bacteria. These compounds share activities found with polymyxin B and derivatives.

Diaza-18-crown-6 appended with two 5-chloro-8-hydroxyquinoline groups can serve as an effective chemosensor for Mg2+. The modified macrocycle will fluoresce in the presence of Mg2+ but not with other alkaline earth ions at pH 7.2. Mg2+ concentrations can be measured in the presence of Na2+, K+, Ca2+, Sr2+ and Ba2+.

New 3′,6′-dideoxy-3′,6′-epithio and 2′,6′-dideoxy-2′,6′-epithionucleosides were prepared from 3′,6′-dideoxy-3′,6′-epithioglucofuranose derivatives, which were obtained from 3-trifluoromethanesulfonyl diacetone allose.

A simple synthetic pathway for the preparation of oxime- and Schiff base-containing aza- and diazacrown ethers is reported. N-Methoxymethyl-substituted aza-15-crown-5 and aza-18-crown-6 as well as N,N′-bis(methoxymethyl)-substituted diaza-18-crown-6 were treated with 5-bromosalicylaldehyde to produce the N-(2′-hydroxy-3′-carbonyl-5′-bromobenzyl)-substituted aza-15-crown-5 (8), aza-18-crown-6 (9) and N,N′-bis(2′-hydroxy-3′-carbonyl-5′-bromobenzyl)-substituted diaza-18-crown-6 (10) compounds. Compounds 8 and 10 were treated with hydroxylamine to give oxime-substituted ligands 12 and 13. A series of bis-Schiff base-containing diaza-18-crown-6 ligands were prepared by reacting 10 with 2-hydroxyaniline (to form 14), 5-nitro-2-hydroxyaniline (15), 2-aminopyridine (16), 2-hydrazinopyridine (17) and N-aminomorpholine (18). Compounds 12–18 are potential complexing agents for simultaneous binding of soft transition and hard alkali or alkaline earth metal ions in one molecule. These new oxime- and Schiff base-containing ligands interacted strongly with Na+ and K+ in methanol. The interaction of the aromatic portions of 9, 10, and 12–15 with transition metal ions was shown by the UV spectra of the metal ion complexes in 50% aqueous DMF. The X-ray structure of 10 is reported.

An enantioselective synthesis of (+)-epoxydictymene (1) is reported. Condensation of the enantiopure aldehydo ester 5 with (S)-3-isopropylcyclopentenyllithium proceeds selectively to afford 13. Once this lactone was methylenated with the Tebbe reagent, the newly formed allyl vinyl ether was induced into Claisen rearrangement under catalysis with triisobutylaluminum. Sequential hydroboration−oxidation of the resulting dicyclopentacyclooctenone derivative was followed by angular methylation and deoxygenation of the carbonyl functionality. Following epimerization at C-11, an α-hydroxyl was introduced regio- and stereoselectively. Some functional group manipulation led to 57 and 58, both of which underwent efficient cyclization to deliver the complete framework of the target molecule when irradiated with visible light in cyclohexane solution containing iodosobenzene diacetate and iodine. The generality of this key reaction, which efficiently constructs the strained oxabicyclo[3.3.0]octane subunit of 1, is dem...

Macrocyclic phosphine oxide-disulfoxides 1a - e and 2a - e were synthesized by oxidation of the corresponding dithioethers with CPBA. Four stereoisomers are possible, but a single stereoisomer was 02 isolated as the major product in each case. This paper describes the structural characterization of several trioxides as well as studies designed to determine the origin of oxidation selectivity.

An enantioselective synthesis of (+)-epoxydictymene, which involves efficient construction of the strained oxabicyclo[3.3.0]octane subunit by irradiation with iodosobenzene diacetate and iodine in cyclohexane solution, is reported.

Preparation of two new glycophanes is reported. These compounds arecomprised of two glucose molecules linked by hydrocarbon units at the 1,1′ and 3, 3′ or 3, 3′ and 6, 6′ positions. Thecrystal structure of one of the glycophanes is also described.

New synthesis techniques are providing increasing control over many inorganic nanoparticle characteristics, facilitating the creation of new multifunctional theranostics. This report proposes the synthesis and testing of a combination nanoparticle comprised of a maghemite core for enhanced T2 MRI contrast diagnostics, a colloidal silver shell acting as an antimicrobial and therapeutic vehicle, and a ceragenin (CSA-124) surfactant providing microbial adhesion. A polyacrylic acid functionalized maghemite nanoparticle is synthesized by a high temperature organic phase reduction followed by thiol functionalization and gold cluster seeding. A silver shell is formed through AgNO 3 reduction, and an oriented monolayer of the thiolated ceragenin, is bound through a self-assembly process. The process and products are characterized throughout synthesis through TEM, DLS, FT-IR, UV–Vis, ICP-OES, HPLC-ESI-TOF-MS, DC magnetization and susceptibility, X-ray diffraction, and in vitro MRI. Synthesized Diagnostic Antimicrobial Nanoparticles (DANs) were found to have a spherical morphology with a diameter of 32.47 ± 1.83 nm, hydrodynamic diameter of 53.05 ± 1.20 nm, maximum magnetic moment of 12 emu/g NP (54 emu/g Fe) with little variation due to temperature, and are predominantly paramagnetic . In vitro MRI studies show that DANs contrast well at concentrations as low as 9 ppm, and successfully adhere to Staphylococcus aureus. DAN MIC was determined to be approximately 12 ppm and 24 ppm against S. aureus and Escherichia coli respectively.

Background Studies of asthma have been limited by a poor understanding of how nonallergic environmental exposures, such as air pollution and infection, are translated in the lung into inflammation and wheezing. Objective Our goal was to understand the mechanism of nonallergic asthma that leads to airway hyperreactivity (AHR), a cardinal feature of asthma independent of adaptive immunity. Method We examined mouse models of experimental asthma in which AHR was induced by respiratory syncytial virus infection or ozone exposure using mice deficient in T-cell immunoglobulin and mucin domain 1 (TIM1/HAVCR1) , an important asthma susceptibility gene. Results TIM1 −/− mice did not have airways disease when infected with RSV or when repeatedly exposed to ozone, a major component of air pollution. On the other hand, the TIM1 −/− mice had allergen-induced experimental asthma, as previously shown. The RSV- and ozone-induced pathways were blocked by treatment with caspase inhibitors, indicating an absolute requirement for programmed cell death and apoptosis. TIM-1–expressing, but not TIM-1–deficient, natural killer T cells responded to apoptotic airway epithelial cells by secreting cytokines, which mediated the development of AHR. Conclusion We defined a novel pathway in which TIM-1, a receptor for phosphatidylserine expressed by apoptotic cells, drives the development of asthma by sensing and responding to injured and apoptotic airway epithelial cells.

Fungal infections, especially those caused by antibiotic resistant pathogens, have become a serious public health problem due to the growing number of immunocompromised patients, including those subjected to anticancer treatment or suffering from HIV infection. In this study we assessed fungicidal activity of the ceragenins CSA-13, CSA-131 and CSA-192 against four fluconazole–resistant Candida strains. We found that ceragenins activity against planktonic Candida cells was higher than activity of human LL-37 peptide and synthetic cationic peptide omiganan. Compared to LL-37 peptide, ceragenins in the presence of DNase I demonstrated an increased ability to kill DNA-induced Candida biofilm. Microscopy studies show that treatment with LL-37 or ceragenins causes Candida cells to undergo extensive surface changes indicating surface membrane damage. This conclusion was substantiated by observation of rapid incorporation of FITC-labeled CSA-13, CSA-131 or LL-37 peptide into the more lipophilic environment of the Candida membrane. In addition to activity against Candida spp., ceragenins CSA-131 and CSA-192 display strong fungicidal activity against sixteen clinical isolates including Cryptococcus neoformans and Aspergillus fumigatus. These results indicate the potential of ceragenins for future development as new fungicidal agents.

Aspergillus fumigatus is a saprophytic fungus that is ubiquitous in the environment and is commonly associated with allergic sensitization and severe asthma in humans. Although A. fumigatus is recognized by multiple microbial pattern-recognition receptors, we found that an A. fumigatus-derived glycosphingolipid, asperamide B, directly activates invariant natural killer T (iNKT) cells in vitro in a CD1d-restricted, MyD88-independent and dectin-1-independent fashion. Moreover, asperamide B, when loaded onto CD1d, directly stained, and was sufficient to activate, human and mouse iNKT cells. In vivo, asperamide B rapidly induced airway hyperreactivity, which is a cardinal feature of asthma, by activating pulmonary iNKT cells in an interleukin-33 (IL-33)-ST2-dependent fashion. Asperamide B is thus the first fungal glycolipid found to directly activate iNKT cells. These results extend the range of microorganisms that can be directly detected by iNKT cells to the kingdom of fungi and may explain how A. fumigatus can induce severe chronic respiratory diseases in humans.

NKT cells are innate-like T cells with powerful regulatory functions that are a promising target for immunotherapy. The efficacy of glycolipids, such as the prototypic NKT cell antagonist α-galactosylceramide (αGalCer), is currently being evaluated in clinical trials, but little is known about factors that target lipid antigens for CD1d presentation and NKT cell activation in vivo. Lipid uptake via the LDL receptor (LDLR) has been shown for digalactosylceramide; however, whether this pathway contributes to CD1d presentation of other important NKT cell agonists remains unclear. We therefore investigated receptor-mediated uptake pathways for CD1d presentation using a panel of structurally diverse lipid antigens. We found that uptake via scavenger receptors was essential for the CD1d presentation of αGalCer and Sphingomonas glycolipids. Moreover, in vivo NKT cell responses, i.e., cytokine production, proliferation, and NKT cell help for adaptive CD4+ and CD8+ T cells, required the uptake of αGalCer via scavenger receptor A. Importantly, our data indicate that structural characteristics of glycolipids determine their receptor binding and direct individual lipids toward different uptake pathways. These results reveal an important contribution of scavenger receptors in the selection of lipids for CD1d presentation and identify structural motifs that may prove useful for therapeutic NKT cell vaccination.

Human Vα24− CD1d-restricted T cells use variation in their CDR1α loop to respond to lipid antigens presented by CD1d, altering their specificities from that of invariant natural killer T cells., CD1d-mediated presentation of glycolipid antigens to T cells is capable of initiating powerful immune responses that can have a beneficial impact on many diseases. Molecular analyses have recently detailed the lipid antigen recognition strategies utilized by the invariant Vα24-Jα18 TCR rearrangements of iNKT cells, which comprise a subset of the human CD1d-restricted T cell population. In contrast, little is known about how lipid antigens are recognized by functionally distinct CD1d-restricted T cells bearing different TCRα chain rearrangements. Here we present crystallographic and biophysical analyses of α-galactosylceramide (α-GalCer) recognition by a human CD1d-restricted TCR that utilizes a Vα3.1-Jα18 rearrangement and displays a more restricted specificity for α-linked glycolipids than that of iNKT TCRs. Despite having sequence divergence in the CDR1α and CDR2α loops, this TCR employs a convergent recognition strategy to engage CD1d/αGalCer, with a binding affinity (∼2 µM) almost identical to that of an iNKT TCR used in this study. The CDR3α loop, similar in sequence to iNKT-TCRs, engages CD1d/αGalCer in a similar position as that seen with iNKT-TCRs, however fewer actual contacts are made. Instead, the CDR1α loop contributes important contacts to CD1d/αGalCer, with an emphasis on the 4′OH of the galactose headgroup. This is consistent with the inability of Vα24− T cells to respond to α-glucosylceramide, which differs from αGalCer in the position of the 4′OH. These data illustrate how fine specificity for a lipid containing α-linked galactose is achieved by a TCR structurally distinct from that of iNKT cells., Author Summary Certain lineages of T cells can recognize lipids as stimulatory antigens when presented in the context of CD1 molecules. We know how most Natural Killer T (NKT) cells react with this unusual ligand because they use a single invariant T cell receptor (TCR) alpha chain to do the job. NKT cells place particular emphasis on their CDR3α and CDR2β loops in recognition of antigen—these complementarity determining regions (CDRs) are the hypervariable parts of the TCR that “complement” an antigen's shape. How do these other T cells recognize closely related yet distinct lipid antigens? Here we show that human CD1d-restricted T cells, typically called Vα24− T cells due to their use of diverse Vα domains in their TCRs, use similar molecular strategies to respond to lipid antigens presented by CD1d. To this end we present a 2.5 Å complex structure of a Vα24− TCR complexed with CD1d presenting the protypical lipid, α-galactosylceramide (αGalCer). The TCR examined in this study notably shifts its binding slightly, placing more emphasis on the interaction with the CDR1α loop as revealed through alanine scanning mutagenesis. This shift explains the inability of these T cells to respond to lipids that vary at this site of contact (the 4'OH), like the related α-linked glucosylceramide. These results provide a molecular basis for the fine-specificity of different CD1d-restricted T cell lineages.

αβ T-cell lines specific for sulfatide, an abundant myelin glycosphingolipid presented by various CD1 molecules, have been previously derived from PBMCs of patients with demyelinating diseases such as multiple sclerosis (MS) but also from healthy subjects. Using an unbiased tetramer-based MACS enrichment method to enrich for rare antigen-specific cells, we confirmed the presence of CD1d-sulfatide-specific T cells in all healthy individuals examined. Surprisingly, the great majority of fresh sulfatide-specific T cells belonged to the γδ lineage. Furthermore, these cells used the Vδ1 TCR variable segment, which is uncommon in the blood but predominates in tissues such as the gut and specifically accumulates in MS lesions. Recombinant Vδ1 TCRs from different individuals were shown to bind recombinant CD1d-sulfatide complexes in a sulfatide-specific manner. These results provide the first direct demonstration of MHC-like-restricted, antigen-specific recognition by γδ TCRs. Together with previous reports, they support the notion that human Vδ1 T cells are enriched in CD1-specific T cells and suggest that the Vδ1 T-cell population that accumulates in MS lesions might be enriched in CD1-sulfatide specific cells.

Ceragenins were used to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. While ceragenins have been used on bio-medical devices, use of ceragenins on water-treatment membranes is novel. Biofouling impacts membrane separation processes for many industrial applications such as desalination, waste-water treatment, oil and gas extraction, and power generation. Biofouling results in a loss of permeate flux and increase in energy use. Creation of biofouling resistant membranes will assist in creation of clean water with lower energy usage and energy with lower water usage. Five methods of attaching three different ceragenin molecules were conducted and tested. Biofouling reduction was observed in the majority of the tests, indicating the ceragenins are a viable solution to biofouling on water treatment membranes. Silane direct attachment appears to be the most promising attachment method if a high concentration of CSA-121a is used. Additional refinement of the attachment methods are needed in order to achieve our goal of several log-reduction in biofilm cell density without impacting the membrane flux. Concurrently, biofilm forming bacteria were isolated from source waters relevant for water treatment: wastewater, agricultural drainage, river water, seawater, and brackish groundwater. These isolates can be used for future testing of methods to control biofouling. Once isolated, the ability of the isolates to grow biofilms was tested with high-throughput multiwell methods. Based on these tests, the following species were selected for further testing in tube reactors and CDC reactors: Pseudomonas ssp. (wastewater, agricultural drainage, and Colorado River water), Nocardia coeliaca or Rhodococcus spp. (wastewater), Pseudomonas fluorescens and Hydrogenophaga palleronii (agricultural drainage), Sulfitobacter donghicola, Rhodococcus fascians, Rhodobacter katedanii, and Paracoccus marcusii (seawater), and Sphingopyxis spp. (groundwater). The testing demonstrated the ability of these isolates to be used for biofouling control testing under laboratory conditions. Biofilm forming bacteria were obtained from all the source water samples.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Cientificoe Tecnologico, Brazil A growing body of evidence demonstrates a correlation between Th2 cytokines and the development of focal and segmental glomerulosclerosis ( FSGS). Therefore, we hypothesized that GSL-1, a monoglycosylceramide from Sphingomonas ssp. with pro-Th1 activity on invariant Natural Killer T ( iNKT) lymphocytes, could counterbalance the Th2 profile and modulate glomerulosclerosis. Using an adriamycin( ADM)-based model of FSGS, we found that BALB/c mice presented albuminuria and glomerular degeneration in association with a Th2-like pro-fibrogenic profile; these mice also expressed a combination of inflammatory cytokines, such as IL-4, IL-1 alpha, IL-1 beta, IL-17, TNF-alpha, and chemokines, such as RANTES and eotaxin. in addition, we observed a decrease in the mRNA levels of GD3 synthase, the enzyme responsible for GD3 metabolism, a glycolipid associated with podocyte physiology. GSL-1 treatment inhibited ADM-induced renal dysfunction and preserved kidney architecture, a phenomenon associated with the induction of a Th1-like response, increased levels of GD3 synthase transcripts and inhibition of pro-fibrotic transcripts and inflammatory cytokines. TGF-beta analysis revealed increased levels of circulating protein and tissue transcripts in both ADM- and GSL-1-treated mice, suggesting that TGF-beta could be associated with both FSGS pathology and iNKT-mediated immunosuppression; therefore, we analyzed the kidney expression of phosphorylated SMAD2/3 and SMAD7 proteins, molecules associated with the deleterious and protective effects of TGF-beta, respectively. We found high levels of phosphoSMAD2/3 in ADM mice in contrast to the GSL-1 treated group in which SMAD7 expression increased. These data suggest that GSL-1 treatment modulates the downstream signaling of TGF-beta through a renoprotective pathway. Finally, GSL-1 treatment at day 4, a period when proteinuria was already established, was still able to improve renal function, preserve renal structure and inhibit fibrogenic transcripts. in conclusion, our work demonstrates that the iNKT agonist GSL-1 modulates the pathogenesis of ADM-induced glomerulosclerosis and may provide an alternative approach to disease management. Universidade Federal de São Paulo, Dept Med Nefrol, São Paulo, Brazil Inst Israelita Ensino & Pesquisa Albert Einstein, Unidade Transplante Renal, São Paulo, Brazil Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA Univ São Paulo, Dept Imunol, São Paulo, Brazil Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, Brazil Universidade Federal de São Paulo, Dept Med Nefrol, São Paulo, Brazil Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, Brazil FAPESP: 2007/07120-0 Conselho Nacional de Desenvolvimento Cientificoe Tecnologico, Brazil: 501848/2009-6 Conselho Nacional de Desenvolvimento Cientificoe Tecnologico, Brazil: 484445/2010-3 Web of Science

Background Asthma has been considered an immunologic disease mediated by T H 2 cells and adaptive immunity. However, clinical and experimental observations suggest that additional pathways might regulate asthma, particularly in its nonallergic forms, such as asthma associated with air pollution, stress, obesity, and infection. Objectives Our goal was to understand T H 2 cell–independent conditions that might lead to airway hyperreactivity (AHR), a cardinal feature of asthma. Methods We examined a murine model of experimental asthma in which AHR was induced with glycolipid antigens, which activate natural killer T (NKT) cells. Results In this model AHR developed rapidly when mice were treated with NKT cell–activating glycolipid antigens, even in the absence of conventional CD4 + T cells. The activated NKT cells directly induced alveolar macrophages to produce IL-33, which in turn activated NKT cells, as well as natural helper cells, a newly described non-T, non-B, innate lymphoid cell type, to increase production of IL-13. Surprisingly, this glycolipid-induced AHR pathway required not only IL-13 but also IL-33 and its receptor, ST2, because it was blocked by an anti-ST2 mAb and was greatly reduced in ST2 −/− mice. When adoptively transferred into IL-13 −/− mice, both wild-type natural helper cells and NKT cells were sufficient for the development of glycolipid-induced AHR. Conclusion Because plant pollens, house dust, and some bacteria contain glycolipids that can directly activate NKT cells, these studies suggest that AHR and asthma can fully develop or be greatly enhanced through innate immune mechanisms involving IL-33, natural helper cells, and NKT cells.

In addition to its antibacterial activity, the cathelicidin-derived LL-37 peptide induces multiple immunomodulatory effects on host cells. Atomic force microscopy, F-actin staining with phalloidin, passage of FITC-conjugated dextran through a monolayer of lung epithelial cells, and assessment of bacterial outgrowth from cells subjected to Pseudomonas aeruginosa infection were used to determine LL-37’s effect on epithelial cell mechanical properties, permeability, and bacteria uptake. A concentration-dependent increase in stiffness and F-actin content in the cortical region of A549 cells and primary human lung epithelial cells was observed after treatment with LL-37 (0.5–5 μM), sphingosine 1-phosphate (1 μM), or LPS (1 μg/ml) or infection with PAO1 bacteria. Other cationic peptides, such as RK-31, KR-20, or WLBU2, and the antibacterial cationic steroid CSA-13 did not reproduce the effect of LL-37. A549 cell pretreatment with WRW4, an antagonist of the transmembrane formyl peptide receptor-like 1 protein attenuated LL-37’s ability to increase cell stiffness. The LL-37–mediated increase in cell stiffness was accompanied by a decrease in permeability and P. aeruginosa uptake by a confluent monolayer of polarized normal human bronchial epithelial cells. These results suggested that the antibacterial effect of LL-37 involves an LL-37–dependent increase in cell stiffness that prevents epithelial invasion by bacteria.

Environmental and genetic factors define the susceptibility of an individual to autoimmune disease. Although common genetic pathways affect general immunological tolerance mechanisms in autoimmunity, the effects of such genes could vary under distinct immune challenges within different tissues. In this study, we demonstrate this by observing that autoimmune type 1 diabetes-protective haplotypes at the insulin-dependent diabetes susceptibility region 10 (Idd10) introgressed from chromosome 3 of C57BL/6 (B6) and A/J mice onto the NOD background increase the severity of autoimmune primary biliary cirrhosis induced by infection with Novosphingobium aromaticivorans, a ubiquitous alphaproteobacterium, when compared with mice having the NOD and NOD.CAST Idd10 type 1 diabetes-susceptible haplotypes. Substantially increased liver pathology in mice having the B6 and A/J Idd10 haplotypes correlates with reduced expression of CD101 on dendritic cells, macrophages, and granulocytes following infection, delayed clearance of N. aromaticivorans, and the promotion of overzealous IFN-γ– and IL-17–dominated T cell responses essential for the adoptive transfer of liver lesions. CD101-knockout mice generated on the B6 background also exhibit substantially more severe N. aromaticivorans-induced liver disease correlating with increased IFN-γ and IL-17 responses compared with wild-type mice. These data strongly support the hypothesis that allelic variation of the Cd101 gene, located in the Idd10 region, alters the severity of liver autoimmunity induced by N. aromaticivorans.

Infection with influenza A virus represents a major public health threat worldwide, particularly in patients with asthma. However, immunity induced by influenza A virus may have beneficial effects, particularly in young children, that might protect against the later development of asthma, as suggested by the hygiene hypothesis. Herein, we show that infection of suckling mice with influenza A virus protected the mice as adults against allergen-induced airway hyperreactivity (AHR), a cardinal feature of asthma. The protective effect was associated with the preferential expansion of CD4–CD8–, but not CD4+, NKT cells and required T-bet and TLR7. Adoptive transfer of this cell population into allergen-sensitized adult mice suppressed the development of allergen-induced AHR, an effect associated with expansion of the allergen-specific forkhead box p3+ (Foxp3+) Treg cell population. Influenza-induced protection was mimicked by treating suckling mice with a glycolipid derived from Helicobacter pylori (a bacterium associated with protection against asthma) that activated NKT cells in a CD1d-restricted fashion. These findings suggest what we believe to be a novel pathway that can regulate AHR, and a new therapeutic strategy (treatment with glycolipid activators of this NKT cell population) for asthma.

Two studies demonstrate that natural killer T-cell adjuvants, covalently attached to either carbohydrate or peptide epitopes, yield effective vaccines.

Abstra: The structure and complexation properties of macrocycles containing atoms from the second row of the periodic table (e.g., sulfur and phosphorus) have received less attention than the corresponding properties of macrocycles containing only first row atoms (e.g., oxygen and nitrogen). We describe results in two areas: macrocyclic thioethers for chelation of late transition metal ions, and macrocycles containing sulfoxide and phosphine oxide groups for complexation of monosaccharide derivatives via multipoint hydrogen bonding.

WOS: 000287482000001, PubMed ID: 21142940, Acanthamoeba is a free-living amoeba causing a potentially blinding infection of the cornea. Acanthamoeba keratitis is difficult to treat, without total efficacy in some patients because of cysts that are less susceptible than trophozoites to the usual treatments. Contact lens wearers are most at risk and account for some 95% of cases. Cationic steroid antibiotic (CSA)-13 is a small molecule aminosterol that has been shown to mimic the activity of endogenous antimicrobial peptides and has bactericidal activity based on membrane disruption. We investigated here the in vitro effectiveness of CSA-13 with a concentration of 100, 75, 50, and 25mg/mL on proliferation of Acanthamoeba castellanii trophozoites and cysts and cytotoxic potential. CSA-13 was evaluated for its amoebicidal activity using an inverted light microscope at 1, 2, 4, 8, 12, and 24 h. For the determination of cytotoxicity of the CSA-13 on L929 cells, agar diffusion tests were performed. CSA-13 inhibited trophozoite growth in dose-and time-dependent ways. At 1 h, no viable trophozoites were observed in the presence of CSA-13 solution in a concentration 100mg/mL in phosphate-buffered saline. Results of cytotoxicity experiments demonstrated that CSA-13 solution had mild toxicity at 100mg/mL concentration on cells, whereas it had no toxicity at 75mg/mL concentration. The findings of this experiment as in vitro ameboebicidal activity for Acanthamoeba suggest that CSA-13 has a potential to be used as a new agent in lens solutions to prevent Acanthamoeba growth and infections.

The human gastric pathogen Helicobacter pylori modifies host cholesterol via glycosylation and incorporates the glycosylated cholesterol into its membrane; however, the benefits of cholesterol to H. pylori are largely unknown. We speculated that cholesterol in the H. pylori membrane might alter the susceptibility of these organisms to membrane-disrupting antibacterial compounds. To test this hypothesis, H. pylori strains were cultured in Ham's F-12 chemically defined medium in the presence or absence of cholesterol. The two cultures were subjected to overnight incubations with serial 2-fold dilutions of 10 bile salts and four ceragenins, which are novel bile salt derivatives that mimic membrane-disrupting activity of antimicrobial peptides. H. pylori cultured with cholesterol was substantially more resistant to seven of the bile salts and three ceragenins than H. pylori cultured without cholesterol. In most cases, these cholesterol-dependent differences ranged from 2 to 7 orders of magnitude; this magnitude depended on concentration of the agent. Cholesterol is modified by glycosylation using Cgt, a cholesteryl glycosyltransferase. Surprisingly, a cgt knockout strain still maintained cholesterol-dependent resistance to bile salts and ceragenins, indicating that cholesterol modification was not involved in resistance. We then tested whether three putative, paralogous inner membrane efflux pumps, HefC, HefF, or HefI, played a role. While HefF and HefI appeared unimportant, HefC was shown to play a critical role in the resistance to bile salts and ceragenins by multiple methods in multiple strain backgrounds. Thus, both cholesterol and the putative bile salt efflux pump HefC play important roles in H. pylori resistance to bile salts and ceragenins.

Oxidation of macrocyclic phosphine oxide-dithioether 1 produces only the dl form of disulfoxide 2. This selectivity can be rationalized by comparing the crystal structures of starting material and product, and on the basis of VT NMR data, which suggest that the starting macrocycle is conformationally constrained in solution.

Abstra: The structure and complexation properties of macrocycles containing atoms from the second row of the periodic table (e.g., sulfur and phosphorus) have received less attention than the corresponding properties of macrocycles containing only first row atoms (e.g., oxygen and nitrogen). We describe results in two areas: macrocyclic thioethers for chelation of late transition metal ions, and macrocycles containing sulfoxide and phosphine oxide groups for complexation of monosaccharide derivatives via multipoint hydrogen bonding.

An enantioselective synthesis of (+)-epoxydictymene, which involves efficient construction of the strained oxabicyclo[3.3.0]octane subunit by irradiation with iodosobenzene diacetate and iodine in cyclohexane solution, is reported.

An enantioselective synthesis of (+)-epoxydictymene (1) is reported. Condensation of the enantiopure aldehydo ester 5 with (S)-3-isopropylcyclopentenyllithium proceeds selectively to afford 13. Once this lactone was methylenated with the Tebbe reagent, the newly formed allyl vinyl ether was induced into Claisen rearrangement under catalysis with triisobutylaluminum. Sequential hydroboration−oxidation of the resulting dicyclopentacyclooctenone derivative was followed by angular methylation and deoxygenation of the carbonyl functionality. Following epimerization at C-11, an α-hydroxyl was introduced regio- and stereoselectively. Some functional group manipulation led to 57 and 58, both of which underwent efficient cyclization to deliver the complete framework of the target molecule when irradiated with visible light in cyclohexane solution containing iodosobenzene diacetate and iodine. The generality of this key reaction, which efficiently constructs the strained oxabicyclo[3.3.0]octane subunit of 1, is dem...

Ceragenins are cholic acid-derived antimicrobial agents that mimic the activity of endogenous antimicrobial peptides. Ceragenins target bacterial membranes, yet the consequences of these interactions have not been fully elucidated. The role of the outer membrane in allowing access of the ceragenins to the cytoplasmic membrane of Gram-negative bacteria was studied using the ML-35p mutant strain of Escherichia coli that has been engineered to allow independent monitoring of small-molecule flux across the inner and outer membranes. The ceragenins CSA-8, CSA-13, and CSA-54 permeabilize the outer membrane of this bacterium, suggesting that the outer membrane does not play a major role in preventing the access of these agents to the cytoplasmic membrane. However, only the most potent of these ceragenins, CSA-13, was able to permeabilize the inner membrane. Interestingly, neither CSA-8 nor CSA-54 caused inner membrane permeabilization over a 30-min period, even at concentrations well above those required for bacterial toxicity. To further assess the role of membrane interactions, we measured membrane depolarization in Gram-positive bacteria with different membrane lipid compositions, as well as in Gram-negative bacteria. We found greatly increased membrane depolarization at the minimal bactericidal concentration of the ceragenins for bacterial species containing a high concentration of phosphatidylethanolamine or uncharged lipids in their cytoplasmic membranes. Although membrane lipid composition affected bactericidal efficiency, membrane depolarization was sufficient to cause lethality, providing that agents could access the cytoplasmic membrane. Consequently, we propose that in targeting bacterial cytoplasmic membranes, focus be placed on membrane depolarization as an indicator of potency.

Macrocyclic phosphine oxide-disulfoxides 1a - e and 2a - e were synthesized by oxidation of the corresponding dithioethers with CPBA. Four stereoisomers are possible, but a single stereoisomer was 02 isolated as the major product in each case. This paper describes the structural characterization of several trioxides as well as studies designed to determine the origin of oxidation selectivity.

Diaza-18-crown-6 appended with two 5-chloro-8-hydroxyquinoline groups can serve as an effective chemosensor for Mg2+. The modified macrocycle will fluoresce in the presence of Mg2+ but not with other alkaline earth ions at pH 7.2. Mg2+ concentrations can be measured in the presence of Na2+, K+, Ca2+, Sr2+ and Ba2+.

Cholic acid derivatives appended with amine groups have been prepared for use as permeabilizers of the outer membranes of Gram-negative bacteria. These compounds interact synergistically with antibiotics such as erythromycin and novobiocin to inhibit growth of Gram-negative bacteria. When a hydrophobic chain is included on the permeabilizers, they can be converted into potent antibiotics. The role of the hydrophobic chain is to facilitate self-promoted transport of the cholic acid derivatives across the outer membrane of Gram-negative bacteria. These compounds share activities found with polymyxin B and derivatives.

Six diaza-18-crown-6 ligands each containing two aromatic side arms with responsive functions were prepared. Diaza-18-crown-6 containing two 4-hydroxyazobenzene or two 4- hydroxy-4'-(dimethylamino)-azobenzene (3 or 4) substituents were prepared via a one-pot Mannich reaction. Diaza-1 8-crown-6 containing two berizimidazole (5), two uracil (6) or two 9,10-anthraquinone (7) substituents were prepared by treating the diazacrown with the appropriate chloromethyl-containing compound. Reductive amination using sodium triacetoxyborohydride, diaza-18-crown-6 and ferrocenecarboxaldehyde was used to prepare bisferrocene-substituted diaza-18-crown-6 (3). Interactions of compounds 3, 5, and 6 with Na(+), K(+), Ba(2+), Ag(+), and Cu(2+) were evaluated by a calorimetric titration technique at 25 deg C in methanol. All three ligands form more stable complexes with Ag(+) and Cu(2+) (5 forms a precipitate with Ag(+)) than with Na(+) and K(+). Ligand 5 also forms a highly stable complex with Ba(2+).

Bisphenol-containing diaza-18-crown-6 ligands (1–16) were synthesized as potential membrane-forming amphiphilesvia the one-pot Mannich reaction. Sonication of the crude products in a small amount of MeOH followed by filtration and drying proved to be an efficient method of purifying nearly all compounds. Compounds8 and9 were selected for assay as amphiphiles. Compared to simple, alkylated diazacrown ethers, the stability of the amphisomes formed from these monomers is lower possibly because intramolecular hydrogen bonding prevents formation of intermolecular hydrogen bonds. Bisphenol-containing diaza-18-crown-6 ligands (1–16) were synthesized as potential membrane-forming amphiphiles. Download : Download full-size image

Ten new 8-hydroxyquinoline-containing diaza-18-crown-6 ligands and analogues were synthesized via a one-pot or stepwise Mannich reaction, reductive amination, or by reacting diaza-18-crown-6 with 5,7-dichloro-2-iodomethyl-8-quinolinol in the presence of N,N-diisopropylethylamine. The Mannich reaction of N,N‘-bis(methoxymethyl)diaza-18-crown-6 with 4-chloro-2-(1H-pyrazol-3-yl)phenol gave the NCH2N-linked bis(3-(5-chloro-2-hydroxy)pyrazol-1-ylmethyl)-substituted diazacrown ether (14) in a 98% yield. The reaction of bis(N,N‘-methoxymethyldiaza)-18-crown-6 with 2.2 equiv of 10-hydroxybenzoquinoline gave only the monosubstituted diazacrown ether ligand (8). Interaction of some of the ligands with various metal ions was evaluated by a calorimetric titration technique at 25 °C in MeOH. Bis(8-hydroxyquinoline-2-ylmethyl)-substituted ligand 13 forms a very strong complex with Ba2+ (log K = 11.6 in MeOH) and is highly selective for Ba2+ over Na+, K+, Zn2+, and Cu2+ (selectivity factor > 106). The 1H NMR spectral st...

Syntheses of 1,3–2,4-calix[4]bis-crown ethers (1 and 2) fixed in the 1,3-alternate conformation by 1,3- and 2,4-bridges made of two modified polyether chains each containing two 1,2-phenylene residues and one pyridine or anisyl unit are reported. The structures of compounds 1 and 2 were established by 1H nmr, 13C nmr, hrms and elemental analyses.

A new 7,16-bis(quinolin-8-ylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane ligand, L, has been prepared and its crystal structure reported. In addition, the structure of the protonated ligand H2L has been determined. H2L is of interest because of interatomic interactions between the ligand and perchlorate ions. The mononuclear Ba(II) (BaL), and dinuclear Cu(II) (Cu2L) complexes of L have been prepared and their crystal structures determined. Stability constants and other thermodynamic data valid in methanol at 23 or 25° for these and several other complexes of L have been obtained. Among the metal ions studied, L forms the most stable complex with Ba2+. In addition, L selectively binds Cu2+ over Ni2+ by about 3 orders of magnitude. Some of the complexes have been studied using nmr and uv-vis spectroscopic techniques. Crystal data are given for L, space group, P21c, a = 8.8325(14) A, b = 13.808(3) A, c = 13.310(3) A; β = 94.72(2)° Z=2, R = 0.0727; for H2L, space group, P21/c, a = 14.685(3) A, b = 15.035(6) A, c = 17.369(4) A, β = 90.366(12)°, Z = 4, R = 0.0781; for BaL, space group, Pbcn, a = 17.314(3) A, b = 9.539(2) A, c = 22.081(3) A, Z = 4, R = 0.0354; and for Cu2L, space group, Cc, a = 19.762(2) A, b = 14.413(2) A, c = 14.935(2) A, β = 98.753(12)°, Z = 4, R = 0.0564. Cu2+ forms a hydroxo-bridged dinuclear complex with L while Ba2+ forms a mononuclear complex with L in which its two side arms are not involved in complexation.

Novel 7,16-bis(8-amino-2-quinolinylmethyl)- and 7,16-bis(8-amino-7-quinolinylmethyl)-diaza-18-crown-6 ligands (12 and 16) have been synthesized by reductive amination of 8-(di-tert-butoxycarbonyl)amino-2-quinolinecarboxaldehyde (followed by removal of the Boc protecting groups) or 8-amino-7-quinolinecarboxaldehyde with diaza-18-crown-6 using triacetoxyborohydride (NaBH(OAc)3) as the reducing agent. The crystal structure of ligand 16 is also given. The absorption spectra of 12 and 16 are dominated by two intense bands at 250±5 and 238±1 nm which are blue shifted upon addition of alkaline earth and heavy metal ions in acetonitrile. In addition, intensities of the fluorescence bands of 12 and 16 are reduced in the presence of metal ions.