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1.
Molecules ; 25(2)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31936166

RESUMO

Lectins mediate adhesion of pathogens to host tissues, filling in a key role in the first steps of infection. Belonging to the opportunistic pathogen Burkholderia cenocepacia, BC2L-C is a superlectin with dual carbohydrate specificity, believed to mediate cross-linking between bacteria and host cells. Its C-terminal domain binds to bacterial mannosides while its N-terminal domain (BCL2-CN) recognizes fucosylated human epitopes. BC2L-CN presents a tumor necrosis factor alpha (TNF-) fold previously unseen in lectins with a novel fucose binding mode. We report, here, the production of a novel recombinant form of BC2L-CN (rBC2L-CN2), which allowed better protein stability and unprecedented co-crystallization with oligosaccharides. Isothermal calorimetry measurements showed no detrimental effect on ligand binding and data were obtained on the binding of Globo H hexasaccharide and l-galactose. Crystal structures of rBC2L-CN2 were solved in complex with two blood group antigens: H-type 1 and H-type 3 (Globo H) by X-ray crystallography. They provide new structural information on the binding site, of importance for the structural-based design of glycodrugs as new antimicrobials with antiadhesive properties.


Assuntos
Antígenos de Grupos Sanguíneos/química , Burkholderia cenocepacia/química , Lectinas/química , Oligossacarídeos/química , Antígenos de Diferenciação/química , Antígenos Glicosídicos Associados a Tumores/química , Sítios de Ligação , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/metabolismo , Cristalografia por Raios X , Epitopos/química , Fucose/química , Expressão Gênica , Humanos , Manosídeos/química , Modelos Moleculares , Ligação Proteica , Proteínas Recombinantes/genética , Fator de Necrose Tumoral alfa/química
2.
Carbohydr Res ; 485: 107815, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31622943

RESUMO

Tripodal nonameric mannoside glycodendrimer 1 with carbohydrate tethered triazole linked with the TRIS-glycine-ß-alanine dipeptidic aromatic centered core was synthesized. Glycodendrimer 1 demonstrated potential in vitro anti-leishmanial activity. The bio-activity data was substantiated with molecular modelling and docking studies of 1 with the three-dimensional protein structure of Leishmanolysin.


Assuntos
Dipeptídeos/síntese química , Dipeptídeos/farmacologia , Glicina/química , Leishmania/efeitos dos fármacos , Manosídeos/química , Triazóis/química , beta-Alanina/química , Antiprotozoários/síntese química , Antiprotozoários/química , Antiprotozoários/metabolismo , Antiprotozoários/farmacologia , Técnicas de Química Sintética , Dendrímeros/química , Dipeptídeos/química , Dipeptídeos/metabolismo , Metaloendopeptidases/química , Metaloendopeptidases/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Conformação Proteica
3.
Chem Commun (Camb) ; 55(85): 12845-12848, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31596280

RESUMO

Multivalent mannosides with inherent macrophage recognition abilities, built on ß-cyclodextrin, RAFT cyclopeptide or peptide dendrimer cores, trigger selective inhibition of lysosomal ß-glucocerebrosidase or α-mannosidase depending on valency and topology, offering new opportunities in multitargeted drug design.


Assuntos
Desenho de Fármacos , Manosídeos/química , Glucosilceramidase/antagonistas & inibidores , Lectinas/química , Macrófagos/metabolismo , Manosídeos/metabolismo , Peptídeos Cíclicos/química , alfa-Manosidase/antagonistas & inibidores , beta-Ciclodextrinas/química
4.
Molecules ; 24(16)2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31426532

RESUMO

A major goal in the discovery of bioactive natural products is to rapidly identify active compound(s) and dereplicate known molecules from complex biological extracts. The conventional bioassay-guided fractionation process can be time consuming and often requires multi-step procedures. Herein, we apply a metabolomic strategy merging multivariate data analysis and multi-informative molecular maps to rapidly prioritize bioactive molecules directly from crude plant extracts. The strategy was applied to 59 extracts of three Bacopa species (B. monnieri, B. caroliniana and B. floribunda), which were profiled by UHPLC-HRMS2 and screened for anti-lipid peroxidation activity. Using this approach, six lipid peroxidation inhibitors 1‒6 of three Bacopa spp. were discovered, three of them being new compounds: monnieraside IV (4), monnieraside V (5) and monnieraside VI (6). The results demonstrate that this combined approach could efficiently guide the discovery of new bioactive natural products. Furthermore, the approach allowed to evidence that main semi-quantitative changes in composition linked to the anti-lipid peroxidation activity were also correlated to seasonal effects notably for B. monnieri.


Assuntos
Bacopa/química , Produtos Biológicos/química , Peroxidação de Lipídeos/efeitos dos fármacos , Manosídeos/química , Manosídeos/farmacologia , Animais , Encéfalo , Química Encefálica , Misturas Complexas/química , Manosídeos/isolamento & purificação , Metabolômica/métodos , Análise Multivariada , Extratos Vegetais/química , Análise de Componente Principal , Ratos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
5.
Int Immunopharmacol ; 74: 105703, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31261037

RESUMO

Drug-induced microRNAs manifest significant therapeutic approaches; however, such progress in the treatment of osteopathic disorders including osteoporosis and rheumatoid arthritis still remains obscure. Contrarily, non-specific drug delivery, at high doses, increases the risk of side effects and reduces drug therapeutic efficacy. Accordingly, the present study was designed to examine the therapeutic effect of berberine coated mannosylated liposomes (ML-BBR) on RANKL (100 ng/ml) stimulated bone marrow-derived monocytes/macrophages (BMMs) via altering miR-23a expression. Initial studies using confocal microscopy showed successful internalization of ML-BBR in RANKL stimulated BMMs. Treatment with ML-BBR abrogated the increased osteoclast formation in BMM cells via inhibiting phosphorylated glutathione synthase kinase beta (p-GSK3ß) mediated NFATc1 activation. Consequently, ML-BBR also attenuated the expression of bone-degrading enzymes (TRAP, cathepsin K and MMP-9) thereby inhibiting the bone resorptive activity of osteoclasts. Moreover, ML-BBR induced the expression levels of miR-23a at the gene level, which in turn attenuated GSK3ß/p-GSK3ß expression as confirmed via blotting analysis. Further miR-23a inhibition of the GSK3ß phosphorylation was confirmed using luciferase reporter assay. Comparatively, LY2090314 (GSK3ß inhibitor) treatment inhibited the protein level expression of GSK3ß/p-GSK3ß. However, LY2090314 treatment induced a basal level expression of miR-23a owing to the suggestion that ML-BBR has an influential role in upregulating miR-23a level to inhibit GSK-3ß phosphorylation. Cumulatively, our findings endorsed that preferential internalization of ML-BBR by BMMs effectively modulated the RANKL/p-GSK3ß pathway and curtailed the osteoclast-mediated bone erosion possibly through post-transcriptional gene silencing via miR-23a.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Berberina/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Macrófagos/fisiologia , MicroRNAs/genética , Osteoclastos/fisiologia , Osteogênese/efeitos dos fármacos , Compostos de Anilina/química , Animais , Berberina/química , Células Cultivadas , Modelos Animais de Doenças , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/genética , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Lipossomos/química , Maleimidas/farmacologia , Manosídeos/química , Microscopia Confocal , Ligante RANK/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Regulação para Cima
6.
Carbohydr Res ; 475: 65-68, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30844665

RESUMO

1-(N-Phenyl)amino-1-deoxy-α-D-manno-hept-2-ulose (2) and two multivalent BSA-based structures 7 and 8, d-manno-configured C-glycosyl-type compounds derived from an Amadori rearrangement, were evaluated as ligands for mannoside-specific lectins of various sources. The determination of the concentration corresponding to 50% of inhibition (IC50) is described. Multivalency turned out to effectively influence ligand selectivity and lectin binding.


Assuntos
Antibacterianos/farmacologia , Lectinas/farmacologia , Manosídeos/farmacologia , Amaryllidaceae/efeitos dos fármacos , Antibacterianos/química , Burkholderia/efeitos dos fármacos , Canavalia/efeitos dos fármacos , Galanthus/efeitos dos fármacos , Lectinas/síntese química , Lectinas/química , Ligantes , Manosídeos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Vicia/efeitos dos fármacos
7.
Med Hypotheses ; 124: 17-20, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30798908

RESUMO

Urinary tract infections are among the most common infectious diseases worldwide, primarily caused by uropathogenic Escherichia coli (UPEC) strains that harbor type I pili and P pili on the surface. Standard E. coli therapy still entails antibiotic consumption, but urinary tract infections tend to recur at a very high rate. Due to the emergence of antibiotic resistant strains of UPEC, as well as high infection recurrence rates, there is a need for new approaches to efficiently treat and prevent urinary tract infections. Since aforementioned adhesive organelles are the principal virulence factors in UPEC, anti-adhesion strategy seems to be the most promising (and hitherto unexplored) treatment option. Here we propose an antiadhesive dual targeting approach towards FimH and PapG adhesive proteins placed on two key virulence factors for UPEC - type I fimbriae and P pili. Such dual antagonists will contain appropriate pharmacophores (mannose and natural cranberry-containing polyphenol) joined together and will more efficiently block the infection and prevent the progression of the disease in comparison to FimH and PapG as isolated targets. More specifically, polyphenol mannosides (due to the structural similarities with the most potent biaryl inhibitors) can act as high-affinity FimH ligands, while cranberry-associated polyphenol moiety can additionally inhibit the PapG-mediated adhesion. Proposed compound may also contribute to the antioxidant capacity of the human organism. In conclusion, this dual-target hypothesis for the prevention and treatment of UPEC infections represents an important foundation for further research on this topic.


Assuntos
Antibacterianos/farmacologia , Infecções por Escherichia coli/prevenção & controle , Infecções Urinárias/prevenção & controle , Escherichia coli Uropatogênica/efeitos dos fármacos , Progressão da Doença , Células Epiteliais/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Fímbrias Bacterianas/efeitos dos fármacos , Humanos , Ligantes , Manose/química , Manosídeos/química , Modelos Moleculares , Estresse Oxidativo , Fenol/química , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/microbiologia , Infecções Urinárias/tratamento farmacológico , Vaccinium macrocarpon/química , Fatores de Virulência/metabolismo
8.
ChemMedChem ; 14(7): 749-757, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30710416

RESUMO

Antimicrobial resistance has become a serious concern for the treatment of urinary tract infections. In this context, an anti-adhesive approach targeting FimH, a bacterial lectin enabling the attachment of E. coli to host cells, has attracted considerable interest. FimH can adopt a low/medium-affinity state in the absence and a high-affinity state in the presence of shear forces. Until recently, mostly the high-affinity state has been investigated, despite the fact that a therapeutic antagonist should bind predominantly to the low-affinity state. In this communication, we demonstrate that fluorination of biphenyl α-d-mannosides leads to compounds with perfect π-π stacking interactions with the tyrosine gate of FimH, yielding low nanomolar to sub-nanomolar KD values for the low- and high-affinity states, respectively. The face-to-face alignment of the perfluorinated biphenyl group of FimH ligands and Tyr48 was confirmed by crystal structures as well as 1 H,15 N-HSQC NMR analysis. Finally, fluorination improves pharmacokinetic parameters predictive for oral availability.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Proteínas de Fímbrias/antagonistas & inibidores , Adesinas de Escherichia coli/química , Adesinas de Escherichia coli/metabolismo , Antibacterianos/administração & dosagem , Antibacterianos/química , Antibacterianos/farmacocinética , Aderência Bacteriana/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Desenho de Fármacos , Escherichia coli/metabolismo , Proteínas de Fímbrias/química , Proteínas de Fímbrias/metabolismo , Polarização de Fluorescência , Espectroscopia de Ressonância Magnética , Manosídeos/administração & dosagem , Manosídeos/química , Manosídeos/farmacocinética , Manosídeos/farmacologia , Conformação Proteica , Eletricidade Estática , Tirosina/metabolismo
9.
Biomacromolecules ; 20(1): 294-304, 2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30512919

RESUMO

Nanoparticles with a covalently bound shell of carbohydrate or sulfate groups, respectively, and a polyethylene core were generated by Ni(II)-catalyzed aqueous copolymerization of ethylene with comonomers undec-10-en-1-yl sulfate, undec-10-en-1-yl ß-d-glucoside or undec-10-en-1-yl α-d-mannoside, respectively. Via remote substituents of the catalyst, the degree of branching and consequently degree of crystallinity of the polyethylene core of the glyconanoparticles could be controlled. This in turn impacts particle shapes, from spherical to anisotropic platelets, as observed by cryo-transmission electron microscopy. Enzyme-linked lectin assays revealed the mannose-decorated nanocrystals to be efficient multivalent ligands for concavalin A.


Assuntos
Manosídeos/química , Nanopartículas/química , Lectinas/química , Polietilenoglicóis/química , Polimerização , Compostos de Enxofre/química
10.
J Antibiot (Tokyo) ; 72(3): 178-180, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30542161

RESUMO

To discover antimicrobial agents from higher fungi, mannonerolidol (3), a new nerolidol mannoside, together with known schizostatin (1) and nerolidol (2) were isolated from an antimicrobial fraction of the culture broth of Schizophyllum commune. Structures of these compounds were determined through spectroscopic methods. Compounds 1 and 3 exhibited antimicrobial activities against plant pathogenic fungi Rhizoctonia solani, Diaporthe sp., Botrytis cinerea, and Alternaria solani and bacteria Bacillus subtilis and Staphylococcus aureus.


Assuntos
Anti-Infecciosos/isolamento & purificação , Meios de Cultura/química , Manosídeos/isolamento & purificação , Schizophyllum/metabolismo , Sesquiterpenos/isolamento & purificação , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Fungos/efeitos dos fármacos , Bactérias Gram-Positivas , Manosídeos/química , Manosídeos/farmacologia , Estrutura Molecular , Schizophyllum/crescimento & desenvolvimento , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Análise Espectral
11.
Acc Chem Res ; 51(11): 2937-2948, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30289687

RESUMO

Preventing bacterial adhesion to host cells is a provocative and alternative approach to traditional antibiotic treatments given the increasing microbial resistance. A brief overview of common antibiotic treatments is described in light of their respective resistance and remaining susceptibility. This strategy has been seriously considered in the context of adherent-invasive infections in Crohn's disease and urinary tract infections in particular. The adhesions of various pathogenic Escherichia coli strains to host cells are primarily mediated through carbohydrate-protein interactions involving bacterial organelles called fimbriae that can recognize specific glycoconjugate receptors on host cells. Of particular interest are the FimH and PapG fimbriae, which bind to mannosylated glycoproteins and glycolipids of the galabiose series, respectively. Therefore, blocking FimH- and PapG-mediated bacterial adhesion to uroepithelial cells by high-affinity carbohydrate antagonists constitutes a challenging therapeutic target of high interest. This is of particular interest since bacterial adhesion to host cells is a parameter unlikely to be the subject of bacterial mutations without affecting the carbohydrate ligand binding interactions at the basis of the recognition and infection processes. To date, there have been several families of potent FimH antagonists that include natural O-linked as well as unnatural analogues of α-d-mannopyranosides. These observations led to a thorough understanding of the intimate binding site interactions that helped to reveal the so-called "tyrosine gate mechanism" at the origin of the strong necessary interactions with sugar-possessing hydrophobic aglycones. By modification of the aglycones of single monosaccharidic d-mannopyranosides, it was possible to replace the natural complex oligomannoside structure by simpler ones. An appealing and successful series of analogues have been disclosed, including nanomolecular architectures such as dendrimers, polymers, and liposomes. In addition, the data were compared to the above multivalent architectures and confirmed the possibility of working with small sugar candidates. This Account primarily concentrates on the most promising types of FimH inhibitors belonging to the family of α-C-linked mannopyranosides. However, one of the drawbacks associated with C-mannopyranosides has been that they were believed to be in the inverted chair conformation, which is obviously not recognized by the E. coli FimH. To decipher this situation, various synthetic approaches, conformational aspects, and restrictions are discussed using molecular modeling, high-field NMR spectroscopy, and X-ray analysis. These combined techniques pointed to the fact that several α-C-linked mannopyranosides do exist in the required 4C1 chair conformation. Ultimately, recent findings in this growing field of interest culminated in the identification of drug candidates that have reached clinical phase I.


Assuntos
Infecções por Escherichia coli/terapia , Manosídeos/química , Adesinas de Escherichia coli/metabolismo , Animais , Antibacterianos , Antígenos CD , Aderência Bacteriana/efeitos dos fármacos , Moléculas de Adesão Celular , Farmacorresistência Bacteriana , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/microbiologia , Proteínas de Fímbrias/antagonistas & inibidores , Proteínas de Fímbrias/metabolismo , Fímbrias Bacterianas/metabolismo , Proteínas Ligadas por GPI , Humanos , Manosídeos/farmacologia , Manosídeos/uso terapêutico , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/patologia
12.
Carbohydr Polym ; 199: 649-660, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143173

RESUMO

Two ß-cyclodextrin derivatives randomly appended on the primary face with both the nitric oxide (NO) photodonor 4-nitro-3-(trifluoromethyl)aniline and a mannose or α(1→2)mannobioside residue are reported to construct targeted NO photoreleasing nanocarriers. 2D ROESY and PGSE NMR suggested supramolecular homodimerization in water by inclusion of the nitroaniline group into the facing macrocycle cavities. Isothermal titration calorimetry on their concanavalin A lectin binding showed an exothermic binding event to the lectin and an endothermic process during the dilution of the conjugates. Both α(1→2)mannobioside and the nitroaniline moieties significantly enhanced the binding to the lectin. These effects might arise from a better fit within the carbohydrate-recognition site in the former case and a multivalent effect caused by homodimerization in the latter. Direct detection of NO by amperometric technique shows that both ß-cyclodextrin derivatives release this radical upon excitation with visible light with higher efficiency than the unfunctionalized NO photodonor.


Assuntos
Concanavalina A/metabolismo , Manosídeos/metabolismo , Doadores de Óxido Nítrico/metabolismo , beta-Ciclodextrinas/metabolismo , Luz , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Substâncias Macromoleculares/metabolismo , Substâncias Macromoleculares/efeitos da radiação , Manosídeos/síntese química , Manosídeos/química , Manosídeos/efeitos da radiação , Óxido Nítrico/análise , Doadores de Óxido Nítrico/síntese química , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/efeitos da radiação , Ligação Proteica , Termodinâmica , beta-Ciclodextrinas/síntese química , beta-Ciclodextrinas/química , beta-Ciclodextrinas/efeitos da radiação
13.
Bioorg Med Chem Lett ; 28(17): 2993-2997, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30017316

RESUMO

FimH is a type I fimbrial lectin located at the tip of type-1 pili of Gram-negative uropathogenic Escherichia coli (UPEC) guiding its ability to adhere and infect urothelial cells. Accordingly, blocking FimH with small molecule inhibitor is considered as a promising new therapeutic alternative to treat urinary tract infections caused by UPEC. Herein, we report that compounds having the S-glycosidic bond (thiomannosides) had improved metabolic stability and plasma exposures when dosed orally. Especially compound 5h showed the potential to inhibit biofilm formation and also to disrupt the preformed biofilm. And compound 5h showed prophylactic effect in UTI model in mice.


Assuntos
Proteínas de Fímbrias/antagonistas & inibidores , Manosídeos/farmacologia , Infecções Urinárias/tratamento farmacológico , Adesinas de Escherichia coli/metabolismo , Administração Oral , Animais , Biofilmes/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Proteínas de Fímbrias/metabolismo , Manosídeos/administração & dosagem , Manosídeos/química , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Infecções Urinárias/urina
14.
Chemistry ; 24(49): 13049-13057, 2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-29939458

RESUMO

Affinity data, such as dissociation constants (KD ) or inhibitory concentrations (IC50 ), are widely used in drug discovery. However, these parameters describe an equilibrium state, which is often not established in vivo due to pharmacokinetic effects and they are therefore not necessarily sufficient for evaluating drug efficacy. More accurate indicators for pharmacological activity are the kinetics of binding processes, as they shed light on the rate of formation of protein-ligand complexes and their half-life. Nonetheless, although highly desirable for medicinal chemistry programs, studies on structure-kinetic relationships (SKR) are still rare. With the recently introduced analytical tool kinITC this situation may change, since not only thermodynamic but also kinetic information of the binding process can be deduced from isothermal titration calorimetry (ITC) experiments. Using kinITC, ITC data of 29 mannosides binding to the bacterial adhesin FimH were re-analyzed to make their binding kinetics accessible. To validate these kinetic data, surface plasmon resonance (SPR) experiments were conducted. The kinetic analysis by kinITC revealed that the nanomolar affinities of the FimH antagonists arise from both (i) an optimized interaction between protein and ligand in the bound state (reduced off-rate constant koff ) and (ii) a stabilization of the transition state or a destabilization of the unbound state (increased on-rate constant kon ). Based on congeneric ligand modifications and structural input from co-crystal structures, a strong relationship between the formed hydrogen-bond network and koff could be concluded, whereas electrostatic interactions and conformational restrictions upon binding were found to have mainly an impact on kon .


Assuntos
Adesinas de Escherichia coli/química , Proteínas de Fímbrias/química , Manosídeos/química , Calorimetria/métodos , Descoberta de Drogas , Proteínas de Fímbrias/antagonistas & inibidores , Ligação de Hidrogênio , Cinética , Ligantes , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Relação Estrutura-Atividade , Termodinâmica
15.
Mol Pharm ; 15(7): 2548-2558, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29768009

RESUMO

The "accelerated blood clearance (ABC) phenomenon" is known to be involved in the adaptive immune system. Regretfully, the relationship between the ABC phenomenon and innate immune system, especially with respect to Kupffer cells (KCs) has been largely unexplored. In this study, the contribution of KCs to ABC was examined using the 4-aminophenyl-α-d-mannopyranoside (APM) lipid derivative DSPE-PEG2000-APM (DPM) and the 4-aminophenyl-ß-l-fucopyranoside (APF) lipid derivative DSPE-PEG2000-APF (DPF) as ligands for mannose/fucose receptors on KCs, which were synthesized and modified on the surface of liposomes. The results of cellular liposome uptake in vitro and biodistribution in vivo indicated that DPM and DPF comodified liposomes (MFPL5-5) present the strongest capability of KC-targeting among all preparations tested. In rats pretreated with MFPL5-5 instead of PEGylated liposomes (PL), the ABC phenomenon was significantly enhanced and the distribution of liposomes in the liver was increased. Cellular uptake of the second injection of PL in vivo demonstrated that KCs was responsible for the uptake. Furthermore, compared to pretreatment with PL, the uptake of second injection of PL was more enhanced when pretreated with MFPL5-5. These findings suggest that KCs, which are considered traditional members of the innate immune system, play a crucial role in the ABC phenomenon and act as a supplement to the phenomenon.


Assuntos
Imunidade Adaptativa , Macrófagos do Fígado/metabolismo , Lectinas Tipo C/metabolismo , Fígado/metabolismo , Lectinas de Ligação a Manose/metabolismo , Receptores de Superfície Celular/metabolismo , Compostos de Anilina/química , Compostos de Anilina/farmacocinética , Animais , Linhagem Celular , Macrófagos do Fígado/imunologia , Ligantes , Lipossomos , Fígado/citologia , Fígado/imunologia , Masculino , Manosídeos/química , Manosídeos/farmacocinética , Taxa de Depuração Metabólica/imunologia , Modelos Animais , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/farmacocinética , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Ratos , Ratos Wistar , Distribuição Tecidual
16.
Antiviral Res ; 154: 116-123, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29630976

RESUMO

Dengue virus (DENV), a mosquito-borne flavivirus, causes severe and potentially fatal symptoms in millions of infected individuals each year. Although dengue fever represents a major global public health problem, the vaccines or antiviral drugs proposed so far have not shown sufficient efficacy and safety, calling for new antiviral developments. Here we have shown that a mannoside glycolipid conjugate (MGC) bearing a trimannose head with a saturated lipid chain inhibited DENV productive infection. It showed remarkable cell promiscuity, being active in human skin dendritic cells, hepatoma cell lines and Vero cells, and was active against all four DENV serotypes, with an IC50 in the low micromolar range. Time-of-addition experiments and structure-activity analyses revealed the importance of the lipid chain to interfere with an early viral infection step. This, together with a correlation between antiviral activity and membrane polarization by the lipid moiety indicated that the inhibitor functions by blocking viral envelope fusion with the endosome membrane. These finding establish MGCs as a novel class of antivirals against the DENV.


Assuntos
Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Glicolipídeos/farmacologia , Manosídeos/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Chlorocebus aethiops , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/virologia , Vírus da Dengue/fisiologia , Descoberta de Drogas , Glicolipídeos/química , Células Hep G2 , Humanos , Concentração Inibidora 50 , Manosídeos/química , Sorogrupo , Células Vero
17.
Chembiochem ; 19(9): 912-916, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29486092

RESUMO

A modular route to prepare functional self-assembling dendritic peptide amphiphiles decorated with mannosides, to effectively target antigen-presenting cells, such as macrophages, is reported. The monomeric building blocks were equipped with tetra(ethylene glycol)s (TEGs) or labeled with a Cy3 fluorescent probe. Experiments on the uptake of the multifunctional supramolecular particles into murine macrophages (Mφs) were monitored by confocal microscopy and fluorescence-activated cell sorting. Mannose-decorated supramolecular polymers trigger a significantly higher cellular uptake and distribution, relative to TEG carrying bare polymers. No cytotoxicity or negative impact on cytokine production of the treated Mφs was observed, which emphasized their biocompatibility. The modular nature of the multicomponent supramolecular polymer coassembly protocol is a promising platform to develop fully synthetic multifunctional vaccines, for example, in cancer immunotherapy.


Assuntos
Células Apresentadoras de Antígenos/metabolismo , Dendrímeros/metabolismo , Manosídeos/metabolismo , Peptídeos/metabolismo , Tensoativos/metabolismo , Animais , Transporte Biológico , Carbocianinas/química , Carbocianinas/metabolismo , Células Cultivadas , Dendrímeros/química , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Macrófagos/metabolismo , Manosídeos/química , Camundongos , Microscopia Confocal , Modelos Moleculares , Peptídeos/química , Polietilenoglicóis/química , Polietilenoglicóis/metabolismo , Tensoativos/química
18.
Int J Biol Macromol ; 107(Pt A): 236-246, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28867234

RESUMO

A native lectin (nPELa), purified from seeds of the species Platypodium elegans, Dalbergieae tribe, was crystallized and structurally characterized by X-ray diffraction crystallography and bioinformatics tools. The obtained crystals diffracted to 1.6Å resolution, and nPELa structure were solved through molecular substitution. In addition, nPELa has a metal binding site and a conserved carbohydrate recognition domain (CRD) similar to other Dalbergieae tribe lectins, such as PAL (Pterocarpus angolensis) and CTL (Centrolobium tomentosum). Molecular docking analysis indicated high affinity of this lectin for different mannosides, mainly trimannosides, formed by α-1,3 or α-1,6 glycosidic bond, as evidenced by the obtained scores. In addition, molecular dynamics simulations were performed to demonstrate the structural behavior of nPELa in aqueous solution. In solution, nPELa was highly stable, and structural modifications in its carbohydrate recognition site allowed interaction between the lectin and the different ligands. Different modifications were observed during simulations for each one of the glycans, which included different hydrogen bonds and hydrophobic interactions through changes in the relevant residues. In addition, nPELa was evaluated for its nociceptive activity in mice and was reported to be the first lectin of the Dalbergieae tribe to show CRD-dependent hypernociceptive activity.


Assuntos
Fabaceae/química , Dor Nociceptiva/tratamento farmacológico , Lectinas de Plantas/química , Polissacarídeos/química , Animais , Sítios de Ligação , Biologia Computacional , Cristalografia por Raios X , Ligação de Hidrogênio , Manosídeos/química , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Dor Nociceptiva/patologia , Lectinas de Plantas/administração & dosagem , Sementes/química
19.
Nanomedicine ; 14(2): 339-351, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29157976

RESUMO

Gold nanoparticles (GNPs) decorated with glycans ameliorate dendritic cells (DC) uptake, antigen-presentation and T-cells cross-talk, which are important aspects in vaccine design. GNPs allow for high antigen loading, DC targeting, lack of toxicity and are straightforward prepared and easy to handle. The present study aimed to assess the capacity of DC to process and present HIV-1-peptides loaded onto GNPs bearing high-mannoside-type oligosaccharides (P1@HM) to autologous T-cells from HIV-1 patients. The results showed that P1@HM increased HIV-specific CD4+ and CD8+ T-cell proliferation and induced highly functional cytokine secretion compared with HIV-peptides alone. P1@HM elicits a highly efficient secretion of pro-TH1 cytokines and chemokines, a moderate production of pro-TH2 and significant higher secretion of pro-inflammatory cytokines such as TNF-α and IL-1ß. Thus, co-delivery of HIV-1 antigens and HM by GNPs is an excellent vaccine delivery system inducing HIV-specific cellular immune responses in HIV+ patients, being a promising approach to improve anti-HIV-1 vaccines.


Assuntos
Células Dendríticas/imunologia , Ouro/química , Infecções por HIV/imunologia , HIV-1/imunologia , Nanopartículas Metálicas/administração & dosagem , Fragmentos de Peptídeos/farmacologia , Linfócitos T/imunologia , Proliferação de Células , Células Cultivadas , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Humanos , Ativação Linfocitária , Manosídeos/química , Nanopartículas Metálicas/química , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/imunologia , Fosfoproteínas/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/virologia , Linfócitos T Citotóxicos/imunologia , Proteínas da Matriz Viral/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia
20.
Acta Biomater ; 64: 200-210, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29024820

RESUMO

Bacterial interference using non-pathogenic Escherichia coli 83972 is a novel strategy for preventing catheter-associated urinary tract infection (CAUTI). Crucial to the success of this strategy is to establish a high coverage and stable biofilm of the non-pathogenic bacteria on the catheter surface. However, this non-pathogenic strain is sluggish to form biofilms on silicone as the most widely used material for urinary catheters. We have addressed this issue by modifying the silicone catheter surfaces with mannosides that promote the biofilm formation, but the stability of the non-pathogenic biofilms challenged by uropathogens over long-term remains a concern. Herein, we report our study on the stability of the non-pathogenic biofilms grown on propynylphenyl mannoside-modified silicone. The result shows that 94% non-pathogenic bacteria were retained on the modified silicone under >0.5 Pa shear stress. After being challenged by three multidrug-resistant uropathogenic isolates in artificial urine for 11 days, large amounts (>4 × 106 CFU cm-2) of the non-pathogenic bacteria remained on the surfaces. These non-pathogenic biofilms reduced the colonization of the uropathogens by >3.2-log. STATEMENT OF SIGNIFICANCE: In bacterial interference, the non-pathogenic Escherichia coli strains are sluggish to form biofilms on the catheter surfaces, due to rapid removal by urine flow. We have demonstrated a solution to this bottleneck by pre-functionalization of mannosides on the silicone surfaces to promote E. coli biofilm formation. A pre-conjugated high affinity propynylphenyl mannoside ligand tethered to the nanometric amino-terminated poly(amido amine) (PAMAM) dendrimer is used for binding to a major E. coli adhesin FimH. It greatly improves the efficiency for the catheter modification, the non-pathogenic biofilm coverage, as well as the (long-term) stability for prevention of uropathogen infections.


Assuntos
Biofilmes/crescimento & desenvolvimento , Materiais Revestidos Biocompatíveis/química , Dendrímeros/química , Escherichia coli/fisiologia , Manosídeos/química , Silicones/química
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