The influence of the carrier molecule on amoxicillin recognition by specific IgE in patients with immediate hypersensitivity reactions to betalactams

10 p.-4 fig.-1 tab.The optimal recognition of penicillin determinants, including amoxicillin (AX), by specific IgE antibodies is widely believed to require covalent binding to a carrier molecule. The nature of the carrier and its contribution to the antigenic determinant is not well known. Here we aimed to evaluate the specific-IgE recognition of different AX-derived structures. We studied patients with immediate hypersensitivity reactions to AX, classified as selective or cross-reactors to penicillins. Competitive immunoassays were performed using AX itself, amoxicilloic acid, AX bound to butylamine (AXO-BA) or to human serum albumin (AXO-HSA) in the fluid phase, as inhibitors, and amoxicilloyl-poli-L-lysine (AXO-PLL) in the solid-phase. Two distinct patterns of AX recognition by IgE were found: Group A showed a higher recognition of AX itself and AX-modified components of low molecular weights, whilst Group B showed similar recognition of both unconjugated and conjugated AX. Amoxicilloic acid was poorly recognized in both groups, which reinforces the need for AX conjugation to a carrier for optimal recognition. Remarkably, IgE recognition in Group A (selective responders to AX) is influenced by the mode of binding and/or the nature of the carrier; whereas IgE in Group B (cross-responders to penicillins) recognizes AX independently of the nature of the carrier.The present study has been supported by Institute of Health “Carlos III” of the Ministry of Economy and Competitiveness (grants cofunded by European Regional Development Fund (ERDF): PI12/02529, PI15/01206, CP15/00103,Red de Reacciones Adversas a Alergenos y Farmacos RD12/0013/0001, RD12/0013/0003 and RD12/0013/0008,RD09/0076/00112 for the Biobank network and PT13/0010/0006 for the Biobank platform) and by State Secretariat for Research, Development and Innovation of the Ministry of Economy and Competitiveness (grants cofunded by European Regional Development Fund (ERDF): MINECO SAF2012-36519, SAF2015-68590-R/FEDER and CTQ2013-41339-P). Andalusian Regional Ministry of Economy and Knowledge (grants cofunded by European Regional Development Fund (ERDF): CTS-06603); Andalusian Regional Ministry Health (grants:PI-0699-2011, PI-0159-2013 and PI-0179-2014) and Merck-Serono Research Grant from Fundación Salud 2000. CM holds a ‘Nicolas Monardes’ research contract by Andalusian Regional Ministry Health: C-0044-2012 SAS 2013. MIM holds a ‘Miguel Servet I’ research contract by Institute of Health “Carlos III” of the Ministry of Economy and Competitiveness (grants cofunded by European Social Fund (ESF)): CP15/00103. AA thanks “pFIS fellowship” (FI08/00385) from ISCIII and Andalucia “Talent Hub Fellowship” (TAHUB/II-004) cofunded by the Junta de Andalucia and the European Union, VII Framework Programme of the European Commission (grant agreement No. 291780).Peer reviewe

Guía docente común de las titulaciones de Ingeniero en Electrónica en las universidades andaluzas

El presente documento constituye el resultado del trabajo elaborado de acuerdo con la Convocatoria de Elaboración de Guías Docentes de Titulaciones Andaluzas conforme al Sistema de Créditos Europeos (años 2005/2006) de la Dirección General de Universidades, dependiente de la Secretaría General de Universidades, Investigación y Tecnología de la Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía

OFF-ON-OFF Fluorescence Switch with T-Latch Function

A novel molecular system with characteristics of an OFF-ON-OFF fluorescence switch was designed to integrate the function of a T-latch. In detail, a receptor(1)-fluorophore-receptor(2) architecture was adopted to achieve fluorescence switching upon addition of protons

7th Drug hypersensitivity meeting: part two

No abstract availabl

Carborane-stilbene dyads: the influence of substituents and cluster isomers on photoluminescence properties

Two novel styrene-containing meta-carborane derivatives substituted at the second carbon cluster atom (Cc) with either a methyl (Me) or a phenyl (Ph) group are introduced herein along with a new set of stilbene-containing ortho- (o-) and meta- (m-) carborane dyads. The latter set of compounds have been prepared from styrene-containing carborane derivatives via a Heck coupling reaction. High regioselectivity has been achieved for these compounds by using a combination of palladium complexes [Pd2(dba)3]/[Pd(t-Bu3P)2] as a catalytic system, yielding exclusively E isomers. All compounds have been fully characterised and the crystal structures of seven of them were analysed by X-ray diffraction. The absorption spectra of these compounds are similar to those of their respective fluorophore groups (styrene or stilbene), showing a very small influence of the substituent (Me or Ph) linked to the second Cc atom or the cluster isomer (o- or m-). On the other hand, fluorescence spectroscopy revealed high emission intensities for Me-o-carborane derivatives, whereas their Ph-o-carborane analogues evidenced an almost total lack of fluorescence, confirming the significant role of the substituent bound to the adjacent Cc in o-carboranes. In contrast, all the m-carborane derivatives display similar photoluminescence (PL) behavior regardless of the substituent attached to the second Cc, demonstrating its small influence on emission properties. Additionally, m-carborane derivatives are significantly more fluorescent than their o-counterparts, reaching quantum yield values as high as 30.2%. Regarding solid state emission, only stilbene-containing Ph-o-carborane derivatives, which showed very low fluorescence in solution, exhibited notable PL emission in films attributed to aggregation-induced emission. DFT calculations were performed to successfully complement the photoluminescence studies, supporting the experimentally observed photophysical behavior of the styrene and stilbene-containing carborane derivatives. In conclusion, in this work it is proved that it is possible to tailor the PL properties of carborane-stilbene dyads by changing the Cc substituent and the carborane isomer.Ministerio de Economía y Competitividad (España)Generalitat de Catalunya“Severo Ochoa” Program for Centers of Excellence in R&DDepto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu

Amoxicillin haptenates intracellular proteins that can be transported in exosomes to target cells.

Allergic reactions to β-lactams are among the most frequent causes of drug allergy and constitute an important clinical problem. Drug covalent binding to endogenous proteins (haptenation) is thought to be required for activation of the immune system. Nevertheless, neither the nature nor the role of the drug protein targets involved in this process is fully understood. Here, we aim to identify novel intracellular targets for haptenation by amoxicillin (AX) and their cellular fate. We have treated B lymphocytes with either AX or a biotinylated analog (AX-B). The identification of protein targets for haptenation by AX has been approached by mass spectrometry and immunoaffinity techniques. In addition, intercellular communication mediated by the delivery of vesicles loaded with AX-B-protein adducts has been explored by microscopy techniques. We have observed a complex pattern of AX-haptenated proteins. Several novel targets for haptenation by AX in B lymphocytes have been identified. AX-haptenated proteins were detected in cell lysates and extracellularly, either as soluble proteins or in lymphocyte-derived extracellular vesicles. Interestingly, exosomes from AX-B-treated cells showed a positive biotin signal in electron microscopy. Moreover, they were internalized by endothelial cells, thus supporting their involvement in intercellular transfer of haptenated proteins. These results represent the first identification of AX-mediated haptenation of intracellular proteins. Moreover, they show that exosomes can constitute a novel vehicle for haptenated proteins, and raise the hypothesis that they could provide antigens for activation of the immune system during the allergic response

Carborane-stilbene dyads: the influence of substituents and cluster isomers on photoluminescence properties.

Two novel styrene-containing meta-carborane derivatives substituted at the second carbon cluster atom (Cc) with either a methyl (Me) or a phenyl (Ph) group are introduced herein along with a new set of stilbene-containing ortho- (o-) and meta- (m-) carborane dyads. The latter set of compounds have been prepared from styrene-containing carborane derivatives via a Heck coupling reaction. High regioselectivity has been achieved for these compounds by using a combination of palladium complexes [Pd2(dba)3]/[Pd(t-Bu3P)2] as a catalytic system, yielding exclusively E isomers. All compounds have been fully characterised and the crystal structures of seven of them were analysed by X-ray diffraction. The absorption spectra of these compounds are similar to those of their respective fluorophore groups (styrene or stilbene), showing a very small influence of the substituent (Me or Ph) linked to the second Cc atom or the cluster isomer (o- or m-). On the other hand, fluorescence spectroscopy revealed high emission intensities for Me-o-carborane derivatives, whereas their Ph-o-carborane analogues evidenced an almost total lack of fluorescence, confirming the significant role of the substituent bound to the adjacent Cc in o-carboranes. In contrast, all the m-carborane derivatives display similar photoluminescence (PL) behavior regardless of the substituent attached to the second Cc, demonstrating its small influence on emission properties. Additionally, m-carborane derivatives are significantly more fluorescent than their o-counterparts, reaching quantum yield values as high as 30.2%. Regarding solid state emission, only stilbene-containing Ph-o-carborane derivatives, which showed very low fluorescence in solution, exhibited notable PL emission in films attributed to aggregation-induced emission. DFT calculations were performed to successfully complement the photoluminescence studies, supporting the experimentally observed photophysical behavior of the styrene and stilbene-containing carborane derivatives. In conclusion, in this work it is proved that it is possible to tailor the PL properties of carborane-stilbene dyads by changing the Cc substituent and the carborane isomer

Detection of glycidic receptors in microalgae using glycodendrons as probes: a new tool for studies on cell surface interactions

Cell recognition, adhesion, and internalization are involved in infectious, reproductive, and inflammatory processes and are generally mediated by interactions between molecules located in the cell membrane and the extracellular matrix. These processes can decrease proliferation rates and they are well known for bacteria, fungi, and animals, but there is a lack of knowledge regarding autotrophic cells. Carbohydrates and proteins (e.g., lectins) are important molecules for cell interactions and information about these molecules is essential to better understand many biological phenomena in uni- or multicellular organisms. Most studies focus on the identification of the carbohydrates present on the cell surface by using labeled lectins. Alternatively, here we present a pioneer research performed by using three different labeled carbohydrates in a multivalent presentation (glycodendrons) to detect the presence of carbohydrate receptors (e.g., lectins) on cell surfaces of 12 algal species. The goal of this study was to detect some specificity in these molecular interactions, but in a reverse way in comparison to that commonly described in the literature. We tested trivalent molecules containing residuals of D-mannose, L-fucose, or N-acetyl-galactosamine to identify their bindings with the corresponding lectins expressed on cell surfaces. We envisage that our new approach could be an alternative tool for taxonomic and physiological studies on microalgae or even on other groups of organisms. Based on our results, the receptors found in the cell surface of the algal species tend to differ in composition, quantity, and distribution. The differences were mainly species-specific, since no patterns were identified at higher taxonomic level. Moreover, like lectins, labeled carbohydrates were proved to be a reliable tool for the study of cell surface composition

Synthesis and multi-target biological profiling of a novel family of rhein derivatives as disease-modifying anti-Alzheimer agents

We have synthesized a family of rhein-huprine hybrids to hit several key targets for Alzheimer"s disease. Biological screening performed in vitro and in Escherichia coli cells has shown that these hybrids exhibit potent inhibitory activities against human acetylcholinesterase butyrylcholinesterase, and BACE-1, dual Aβ42 and tau anti-aggregating activity, and brain permeability. Ex vivo studies with the leads (+)- and (-)-7e in brain slices of C57bl6 mice have revealed that they efficiently protect against the Aβ-induced synaptic dysfunction , preventing the loss of synaptic proteins and/or have a positive effect on the induction of long term potentiation. In vivo studies in APP-PS1 transgenic mice treated i.p. for 4 weeks with (+)- and (-)-7e have shown a central soluble Aβ lowering effect, accompanied by an increase in the levels of mature amyloid precursor protein (APP). Thus, (+)- and (-)-7e emerge as very promising disease-modifying anti-Alzheimer drug candidates

The C-terminus of H-ras as a target for the covalent binding of reactive compounds modulating Ras-dependent pathways

Ras proteins are crucial players in differentiation and oncogenesis and constitute important drug targets. The localization and activity of Ras proteins are highly dependent on posttranslational modifications at their C-termini. In addition to an isoprenylated cysteine, H-Ras, but not other Ras proteins, possesses two cysteine residues (C181 and C184) in the C-terminal hypervariable domain that act as palmitoylation sites in cells. Cyclopentenone prostaglandins (cyPG) are reactive lipidic mediators that covalently bind to H-Ras and activate H-Ras dependent pathways. Dienone cyPG, such as 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2) and Δ12-PGJ2 selectively bind to the H-Ras hypervariable domain. Here we show that these cyPG bind simultaneously C181 and C184 of H-Ras, thus potentially altering the conformational tendencies of the hypervariable domain. Based on these results, we have explored the capacity of several bifunctional cysteine reactive small molecules to bind to the hypervariable domain of H-Ras proteins. Interestingly, phenylarsine oxide (PAO), a widely used tyrosine phosphatase inhibitor, and dibromobimane, a cross-linking agent used for cysteine mapping, effectively bind H-Ras hypervariable domain. The interaction of PAO with H-Ras takes place in vitro and in cells and blocks modification of H-Ras by 15d-PGJ2. Moreover, PAO treatment selectively alters H-Ras membrane partition and the pattern of H-Ras activation in cells, from the plasma membrane to endomembranes. These results identify H-Ras as a novel target for PAO. More importantly, these observations reveal that small molecules or reactive intermediates interacting with spatially vicinal cysteines induce intramolecular cross-linking of H-Ras C-terminus potentially contributing to the modulation of Ras-dependent pathways.This work was supported by European Union Cooperation in the field of Scientific and Technical research (COST) Action CM1001, grant SAF2009-11642 from Ministerio de Ciencia e Innovación and Red Temática de Investigación Cooperativa from Instituto de Salud Carlos II (Spain) RD07/0064/0007 to DP-S and RD07/0064/0000 to EP-I. Work at Universitat Pompeu Fabra was supported by grants BIO2005-07592-CO2-02 and BIO2008-04487-CO3-02 from Ministerio de Ciencia e Innovación (Spain) to DA, and by the regional government of Catalunya (SGR2005-00494). JMR’s work is supported by Fondo de Investigaciones Sanitarias-Intrasalud (PS09/00562) and Red Temática de Investigación Cooperativa RD06/0020/0003 from Instituto de Salud Carlos III, and the Spanish Association Against Cancer (AECC). CLO is the recipient of a predoctoral fellowship from the Formación de Personal Investigador (FPI) program (Ministerio de Ciencia e Innovación, Spain, BES-2010-033718). CAG-D is the recipient of a fellowship from Fondo de Investigaciones Sanitarias-Beca de Formación en Investigación. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscri