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Glycan arrays
Abstracts / Comparative Biochemistry and Physiology, Part A 150 (2008) S162–S166
S165
trials that may prove useful for diagnosing disease and monitoring progression and therapy.
thousands of blood sera. These screens involve all major disease areas.
doi:10.1016/j.cbpa.2008.04.431
References
C4.11 Interactions between cancer cell glycans and endothelial cells during adhesion and transmigration events in metastasis H. Lomax-Browne, S. Brooks (Oxford Brookes University) Aberrant glycosylation is an established characteristic of cancer cells, and appears to have a functional role in metastasis — the process by which cancer cells spread around the body. The lectin from Helix pomatia, the Roman snail, (H. pomatia agglutinin, HPA) recognises cancer-associated aberrant glycans terminating in the monosaccharide α-N-acetylgalactosamine (GalNAc). The presence of these GalNAc-glycans, detected by HPA binding, is associated with metastasis and consequent poor survival. We are investigating the putative functional role of these glycans in cancer cell adhesion to, and migration through, the endothelium (lining blood vessels) during metastasis. A study by our group investigated the adhesion of eight breast cell lines; one normal breast cell line, and seven breast cancer cell lines with increasingly greater amounts of GalNAc-glycans, consistent with their increasing metastatic ability, to an endothelial cell monolayer from human brain microvasculature, a site physiologically relevant to breast cancer metastasis. This study provided novel evidence that GalNAc-glycanson breast cancer cells have a functional role in breast cancer cell adhesion to endothelial cells. It was also found that the HPA binding profiles of the breast cell lines appear to correlate with their abilities to adhere to endothelial cells via GalNAc-glycans. A study is also currently being carried out to aim to identify the receptors on the endothelial cells that bind to the GalNAc-glycans on the breast cancer cells. doi:10.1016/j.cbpa.2008.04.432
C4.12 Glycan arrays P. Seeberger (Swiss Federal Institute of Technology (ETH), Zurich) Carbohydrate arrays using defined, synthetic oligosaccharides that are covalently linked to the surface of a chip by depositing with high-precision printing equipment have now become the standard in the field Ratner et al. (2004). Such carbohydrate arrays have been used to study carbohydrate–protein, Adams et al. (2004) carbohydrate–RNA Disney and Seeberger (2004a) and carbohydrate–cell interactions Disney and Seeberger (2004b). Many other laboratories have used arrays to study a host of such interactions. The limiting factor to apply carbohydrate arrays more widely is access to defined molecules in sufficient quantities. An automated solid-phase oligosaccharide synthesizer we developed fuels now our carbohydrate array work Plante et al. (2001). This lecture will describe examples from all areas of glycan arrays including heparin arrays, de Paz et al. (2006) GPI arrays Kamena et al. (2008) and phosphatidyl inositol mannoside (PIM) arrays. These arrays and others containing synthetic oligosaccharides are used to screen
Ratner, D.M., Adams, E.W., Su, J., O'Keefe, B.R., Mrksich, M., Seeberger, P.H., 2004. Probing protein–carbohydrate interactions with microarrays of synthetic oligosaccharides. ChemBioChem 5, 379. Adams, E.W., Ratner, D.M., Bokesh, H.R., McMahon, J.B., O'Keefe, B.R., Seeberger, P.H., 2004. Oligosaccharide and glycoprotein microarrays as tools in HIV-glycobiology: glycan dependent gp120/ protein interactions. Chem. Biol. 11, 875. Disney, M.D., Seeberger, P.H., 2004a. Aminoglycoside microarrays to explore carbohydrate–RNA interactions. Chem. Eur. J. 10, 3308. Disney, M.D., Seeberger, P.H., 2004b. The use of carbohydrate microarrays to study carbohydrate–cell interactions and to detect pathogens. Chem. Biol. 11, 1701. Plante, O.J., Palmacci, E.R., Seeberger, P.H., 2001. Automated solidphase synthesis of oligosaccharides. Science 291, 1523. de Paz, J.L., Noti, C., Seeberger, P.H., 2006. Microarrays of synthetic heparin oligosaccharides. J. Am.Chem. Soc. 128, 2766. Kamena, F., Tamborrini, M., Liu, X., Kwon, Y.-U., Thompson, F., Pluschke, G., Seeberger, P.H., 2008. Nature Chem. Bio. 4, 238–240. Liu, X., Boonratthakalin, S., Kamena, F., Seeberger, P.H., in preparation. Preparation and use of synthetic PIM microarrays. doi:10.1016/j.cbpa.2008.04.433
C4.13 C-type lectins on dendritic cells induce Raf-1 signaling to dictate adaptive immune responses against pathogens T. Geijtenbeek, S. Gringhuis, J. den Dunnen (VUMC)
Adaptive immune responses by dendritic cells (DCs) are critically controlled by pathogen recognition. C-type lectins are important pathogen receptors but little is known about the signaling pathways triggered by C-type lectins and how the induced signaling after pathogen binding is translated into specific cytokine programs to induce adaptive immunity. Here, we will discuss a novel molecular signaling pathway induced by the C-type lectin DC-SIGN that modulates TLR signaling at the level of both NF-kB activation to induce pathogen-tailored immunity. We demonstrate that different pathogens trigger DC-SIGN on human DCs to activate the serine/threonine kinase Raf-1. Strikingly, our data demonstrate that pathogens induce different downstream effectors of Raf-1 and thereby induce pathogen specific immune responses. Binding of DC-SIGN to pathogens, such as Mycobacterium tuberculosis, M. leprae, Candida albicans, Measles virus and HIV-1, induces Raf-1 signaling that leads to acetylation of the NFkB subunit p65, however only after TLR-induced activation of NF-kB. Acetylation of p65 both prolongs and increases IL-10 transcription to enhance the anti-inflammatory cytokine responses. Therefore, our data have identified an important role for Raf-1 in the differentiation of immune responses against pathogens. Further knowledge about the downstream effectors of Raf-1 that determine the specific signaling pathways will be instrumental in understanding adaptive immunity, and might identify promising targets to combat immune suppression by pathogens.
doi:10.1016/j.cbpa.2008.04.434
S165
trials that may prove useful for diagnosing disease and monitoring progression and therapy.
thousands of blood sera. These screens involve all major disease areas.
doi:10.1016/j.cbpa.2008.04.431
References
C4.11 Interactions between cancer cell glycans and endothelial cells during adhesion and transmigration events in metastasis H. Lomax-Browne, S. Brooks (Oxford Brookes University) Aberrant glycosylation is an established characteristic of cancer cells, and appears to have a functional role in metastasis — the process by which cancer cells spread around the body. The lectin from Helix pomatia, the Roman snail, (H. pomatia agglutinin, HPA) recognises cancer-associated aberrant glycans terminating in the monosaccharide α-N-acetylgalactosamine (GalNAc). The presence of these GalNAc-glycans, detected by HPA binding, is associated with metastasis and consequent poor survival. We are investigating the putative functional role of these glycans in cancer cell adhesion to, and migration through, the endothelium (lining blood vessels) during metastasis. A study by our group investigated the adhesion of eight breast cell lines; one normal breast cell line, and seven breast cancer cell lines with increasingly greater amounts of GalNAc-glycans, consistent with their increasing metastatic ability, to an endothelial cell monolayer from human brain microvasculature, a site physiologically relevant to breast cancer metastasis. This study provided novel evidence that GalNAc-glycanson breast cancer cells have a functional role in breast cancer cell adhesion to endothelial cells. It was also found that the HPA binding profiles of the breast cell lines appear to correlate with their abilities to adhere to endothelial cells via GalNAc-glycans. A study is also currently being carried out to aim to identify the receptors on the endothelial cells that bind to the GalNAc-glycans on the breast cancer cells. doi:10.1016/j.cbpa.2008.04.432
C4.12 Glycan arrays P. Seeberger (Swiss Federal Institute of Technology (ETH), Zurich) Carbohydrate arrays using defined, synthetic oligosaccharides that are covalently linked to the surface of a chip by depositing with high-precision printing equipment have now become the standard in the field Ratner et al. (2004). Such carbohydrate arrays have been used to study carbohydrate–protein, Adams et al. (2004) carbohydrate–RNA Disney and Seeberger (2004a) and carbohydrate–cell interactions Disney and Seeberger (2004b). Many other laboratories have used arrays to study a host of such interactions. The limiting factor to apply carbohydrate arrays more widely is access to defined molecules in sufficient quantities. An automated solid-phase oligosaccharide synthesizer we developed fuels now our carbohydrate array work Plante et al. (2001). This lecture will describe examples from all areas of glycan arrays including heparin arrays, de Paz et al. (2006) GPI arrays Kamena et al. (2008) and phosphatidyl inositol mannoside (PIM) arrays. These arrays and others containing synthetic oligosaccharides are used to screen
Ratner, D.M., Adams, E.W., Su, J., O'Keefe, B.R., Mrksich, M., Seeberger, P.H., 2004. Probing protein–carbohydrate interactions with microarrays of synthetic oligosaccharides. ChemBioChem 5, 379. Adams, E.W., Ratner, D.M., Bokesh, H.R., McMahon, J.B., O'Keefe, B.R., Seeberger, P.H., 2004. Oligosaccharide and glycoprotein microarrays as tools in HIV-glycobiology: glycan dependent gp120/ protein interactions. Chem. Biol. 11, 875. Disney, M.D., Seeberger, P.H., 2004a. Aminoglycoside microarrays to explore carbohydrate–RNA interactions. Chem. Eur. J. 10, 3308. Disney, M.D., Seeberger, P.H., 2004b. The use of carbohydrate microarrays to study carbohydrate–cell interactions and to detect pathogens. Chem. Biol. 11, 1701. Plante, O.J., Palmacci, E.R., Seeberger, P.H., 2001. Automated solidphase synthesis of oligosaccharides. Science 291, 1523. de Paz, J.L., Noti, C., Seeberger, P.H., 2006. Microarrays of synthetic heparin oligosaccharides. J. Am.Chem. Soc. 128, 2766. Kamena, F., Tamborrini, M., Liu, X., Kwon, Y.-U., Thompson, F., Pluschke, G., Seeberger, P.H., 2008. Nature Chem. Bio. 4, 238–240. Liu, X., Boonratthakalin, S., Kamena, F., Seeberger, P.H., in preparation. Preparation and use of synthetic PIM microarrays. doi:10.1016/j.cbpa.2008.04.433
C4.13 C-type lectins on dendritic cells induce Raf-1 signaling to dictate adaptive immune responses against pathogens T. Geijtenbeek, S. Gringhuis, J. den Dunnen (VUMC)
Adaptive immune responses by dendritic cells (DCs) are critically controlled by pathogen recognition. C-type lectins are important pathogen receptors but little is known about the signaling pathways triggered by C-type lectins and how the induced signaling after pathogen binding is translated into specific cytokine programs to induce adaptive immunity. Here, we will discuss a novel molecular signaling pathway induced by the C-type lectin DC-SIGN that modulates TLR signaling at the level of both NF-kB activation to induce pathogen-tailored immunity. We demonstrate that different pathogens trigger DC-SIGN on human DCs to activate the serine/threonine kinase Raf-1. Strikingly, our data demonstrate that pathogens induce different downstream effectors of Raf-1 and thereby induce pathogen specific immune responses. Binding of DC-SIGN to pathogens, such as Mycobacterium tuberculosis, M. leprae, Candida albicans, Measles virus and HIV-1, induces Raf-1 signaling that leads to acetylation of the NFkB subunit p65, however only after TLR-induced activation of NF-kB. Acetylation of p65 both prolongs and increases IL-10 transcription to enhance the anti-inflammatory cytokine responses. Therefore, our data have identified an important role for Raf-1 in the differentiation of immune responses against pathogens. Further knowledge about the downstream effectors of Raf-1 that determine the specific signaling pathways will be instrumental in understanding adaptive immunity, and might identify promising targets to combat immune suppression by pathogens.
doi:10.1016/j.cbpa.2008.04.434