Potentiation of Fibroblast Growth Factor Activity by Synthetic Heparin Oligosaccharide Glycodendrimers

275

175

It is widely accepted that the heavily glycosylated glycoprotein gp120 on the surface of HIV-1 shields peptide epitopes from recognition by the immune system and may promote infection in vivo by interaction with dendritic cells and transport to tissue rich in CD4 ؉ T cells such as lymph nodes. A conserved cluster of oligomannose glycans on gp120 has been identified as the epitope recognized by the broadly HIV-1-neutralizing monoclonal antibody 2G12. Oligomannose glycans are also the ligands for DC-SIGN, a C-type lectin found on the surface of dendritic cells. Multivalency is fundamental for carbohydrate-protein interactions, and mimicking of the high glycan density on the virus surface has become essential for designing carbohydrate-based HIV vaccines and antiviral agents. We report an efficient synthesis of oligomannose dendrons, which display multivalent oligomannoses in high density, and characterize their interaction with 2G12 and DC-SIGN by a glycan microarray binding assay. The solution and the surface binding analysis of 2G12 to a prototype oligomannose dendron clearly demonstrated the efficacy of dendrimeric display. We further showed that these glycodendrons inhibit the binding of gp120 to 2G12 and recombinant dimeric DC-SIGN with IC 50 in the nanomolar range. A second-generation Man 9 dendron was identified as a potential immunogen for HIV vaccine development and as a potential antiviral agent.glycodendron ͉ high mannose ͉ multivalency ͉ HIV vaccine ͉ antiviral agent

Section: Resultsmentioning

confidence: 99%

“…Over the past several years, many groups have found that glycodendrimers/ glycodendrons exhibit strikingly enhanced affinity against target proteins (23,31,32). More recently, different synthetic approaches and applications of these macromolecules have been explored (33)(34)(35)(36).…”

mentioning

confidence: 99%

Targeting the carbohydrates on HIV-1: Interaction of oligomannose dendrons with human monoclonal antibody 2G12 and DC-SIGN

Wang

Liang

Astronomo

et al. 2008

275

175

“…Several methods have been developed to study GAG-protein interactions, including affinity chromatography, analytical ultracentrifugation, electrophoretic mobility shift assays, competition experiments, mass spectrometry-based approaches, isothermal titration calorimetry, and surface plasmon resonance (9)(10)(11)(12)(13)(14)(15)(16). Although powerful, these approaches are low throughput, often labor intensive, and require significant quantities of carbohydrate and/or protein.…”

mentioning

confidence: 99%

Elucidating glycosaminoglycan–protein–protein interactions using carbohydrate microarray and computational approaches

Rogers

Clark

Tully

et al. 2011

100

Glycosaminoglycan polysaccharides play critical roles in many cellular processes, ranging from viral invasion and angiogenesis to spinal cord injury. Their diverse biological activities are derived from an ability to regulate a remarkable number of proteins. However, few methods exist for the rapid identification of glycosaminoglycan-protein interactions and for studying the potential of glycosaminoglycans to assemble multimeric protein complexes. Here, we report a multidisciplinary approach that combines new carbohydrate microarray and computational modeling methodologies to elucidate glycosaminoglycan-protein interactions. The approach was validated through the study of known protein partners for heparan and chondroitin sulfate, including fibroblast growth factor 2 (FGF2) and its receptor FGFR1, the malarial protein VAR2CSA, and tumor necrosis factor-α (TNF-α). We also applied the approach to identify previously undescribed interactions between a specific sulfated epitope on chondroitin sulfate, CS-E, and the neurotrophins, a critical family of growth factors involved in the development, maintenance, and survival of the vertebrate nervous system. Our studies show for the first time that CS is capable of assembling multimeric signaling complexes and modulating neurotrophin signaling pathways. In addition, we identify a contiguous CS-E-binding site by computational modeling that suggests a potential mechanism to explain how CS may promote neurotrophin-tyrosine receptor kinase (Trk) complex formation and neurotrophin signaling. Together, our combined microarray and computational modeling methodologies provide a general, facile means to identify new glycosaminoglycan-protein-protein interactions, as well as a molecular-level understanding of those complexes. G lycosaminoglycans (GAGs) regulate a wide range of physiological processes, including viral invasion, blood coagulation, cell growth, and spinal cord injury (1-4). Assembled from repeating disaccharide units, GAGs display diverse patterns of sulfation (SI Appendix, Fig. S1). These sulfation patterns are believed to have important functional consequences, enabling the polysaccharides to interact with a wide variety of proteins (1, 2). However, the precise sulfation motifs involved in protein recognition are understood in only a few cases (1,4,5). Moreover, studies of heparan sulfate (HS) interactions with fibroblast growth factors suggest that GAGs can assist in the assembly of multimeric protein complexes, thereby modulating signal transduction pathways (6-10). Yet, only a few such examples have been elucidated, and the extent to which other GAGs such as chondroitin sulfate (CS) engage in the formation of multimeric protein complexes remains unknown. Elucidating the interactions of specific GAG substructures with proteins and large protein-protein complexes will be critical for understanding the structure-activity relationships of GAGs and the mechanisms underlying important biological processes.Several methods have been developed to study GAG-protein interac...

“…Thus, we analyzed the binding profile of CCL20 to a heparin-like carbohydrate library, which contains carbohydrates with various sulfation patterns ranging from monosaccharides to hexasaccharides (Fig. 3A) by our glycan microarray system (18,19). The screening results showed that CCL20 strongly bound to hexasaccharides 1, 2, and moderately bound to hexasaccharide 5 and tetrasaccharide 7.…”

Section: Interruption Of Lymphocyte Trafficking Pathway Attenuates Asmentioning

confidence: 99%

“…Nevertheless, the nontemplate nature of long carbohydrate chains (<25,000 disaccharide units) and conformational plasticity still make it difficult to identify the common sequences of heparan sulfate that display affinity to specific chemokines. In this regard, our previously established glycan microarray system (18,19) is a powerful tool to define the selectivity in heparan sulfate-chemokine interactions.…”

mentioning

confidence: 99%

Synthetic di-sulfated iduronic acid attenuates asthmatic response by blocking T-cell recruitment to inflammatory sites

Nonaka

Bao

Matsumura

et al. 2014

Self Cite

Identification of carbohydrate sequences that determine affinity to specific chemokines is a critical step for strategies to interfere with chemokine-mediated leukocyte trafficking. Here, we first characterized the development of allergic asthma in Tie2-dependent and inducible Ext1-knockout (Tie2-Ext1 iKO ) mice. We showed that heparan sulfate is essential for leukocyte recruitment in the peribronchial region and bronchoalveolar lavage fluid (BALF), and is crucial for induction of airway hyperresponsiveness. Our glycan microarray showed a unique affinity profile of chemokine CCL20 to substructures of heparin and heparin-like oligo/di/monosaccharides. Among them, we identified a synthetic and not naturally occurring monosaccharide, 2,4-O-di-sulfated iduronic acid (Di-S-IdoA), as a potential inhibitor for CCL20-heparan sulfate interaction. Mice injected with Di-S-IdoA via tail vain or nasal inhalation showed attenuated leukocyte recruitment into inflammatory sites and BALF. These results demonstrate a critical role of chemokine-heparan sulfate interaction in the asthma development and Di-S-IdoA as a potential drug for asthma treatment.