My laboratory is concerned with the molecular basis and physiology of glycosphingolipid (GSL) receptor function. Globotriaosyl ceramide (Gb3) binding is the mechanism by which verotoxin targets renal endothelial cells to initiate the pathology which is characteristic of hemolytic uremic syndrome. Our interests are focused on the role of glycolipid receptor heterogeneity in determining the sensitivity of cells to verotoxin-induced apoptosis and intracellular targeting of the toxin. This is related to the (lipid determined) organization of the glycolipid within the membrane bilayer. We have made soluble glycolipid analogues which in part, mimic these properties. These will be used to probe the role of glycolipids and organization in microbial pathogenesis.
We have found that certain human tumor cells and their neovasculature express
Gb3 . VT can be used to treat xenograft models of such tumors. We are studying the link between drug resistance and increased their Gb3 synthesis/VT sensitivity. We have shown the major drug pump, MDR1, is directly involved in GSL biosynthesis in the Golgi. Gb3 is also involved in HIV binding and fusion. These processes can be modulated by soluble GSL analogues.
Future Research
Our future studies will attempt to define the functional components within glycolipids and their ligands. We will use the glycolipid mimics we have made to inhibit these interactions and prevent the clinical pathology they mediate. The use of verotoxin as an antineoplastic/antiangiogenic agent and GSL mimics to prevent HIV infection offer new directions in translational research.
Intellectual Property/ Licensing Opportunities
Glycolipid Mimics and Methods of Use Thereof (US 5,973,128)
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Chark,D., Nutikka A., Trusevych,N., Kuzmina, J. and Lingwood, CA. Differential carbohydrate epitope recognition of globotriaosyl ceramide by verotoxins and monoclonal antibody: Role in human renal glomerular binding. Eur J Biochem 271:405-417, 2004.
DeRosa, M. F., Ackerley, C. and Lingwood, CA. Role of Multiple Drug Resistance Protein 1 in neutral but not acidic glycosphingolipid biosynthesis. J Biol Chem 279:7867-7876, 2004.
Whetstone, H., and Lingwood CA. 3'Sulfogalactolipid binding specifically inhibits Hsp70 ATPase activity in vitro. Biochemistry 42:1611-1617, 2003.
Heath-Engel, H. and Lingwood, CA. Verotoxin sensitivity of ECV304 cells in vitro and in vivo in a xenograft mode. Angiogenesis 6(2): 129-41, 2003.
Mahfoud, R., Mylvaganam M, Lingwood CA and Fantini, J. A novel soluble analog of the HIV-1 fusion cofactor, globotriaosylceramide (Gb3), eliminates the cholesterol requirement for high affinity gp120/Gb3 interaction. J Lip Res 43:1670-1679, 2002.
Mamelak D, Lingwood CA. The ATPase domain
of Hsp70 possesses a unique binding specificity for
3’ sulfogalactolipids. J Biol Chem 276:449-456,
2001.
Mamelak D, Mylvaganam M, Whetstone H, Hartmann E, Lennarz
W, Wyrick P, Raulston J, Han H, Hoffman P, Lingwood
CA. Hsp70s contain a specific sulfogalactolipid
binding site. Differential aglycone influence on sulfogalactosyl
ceramide binding by recombinant prokaryotic and eukaryotic
hsp70 family members. Biochemistry 40:3572-3582,
2001.
Lala P, Ito S, Lingwood CA. Retroviral transfection
of Madin-Darby canine kidney cells with human MDR1
results in a major increase in globotriaosylceramide
and 10(5)- to 10(6)-fold increased cell sensitivity
to verocytotoxin. Role of p-glycoprotein in glycolipid
synthesis. Journal of Biological Chemistry, 275:
6246-6251, 2000.
Khine AA, Lingwood CA. Functional significance
of globotriaosyl ceramide in interferon-alpha(2)/type
1 interferon receptor-mediated antiviral activity.
Journal of Cell Physiology, 182: 97-108, 2000.
Mylvaganam M, Lingwood CA. Adamantyl globotriaosyl
ceramide: a monovalent soluble mimic which inhibits
verotoxin binding to its glycolipid receptor.
Biochemical Biophysical Research Communications, 257:
391-394, 1999.
Mylvaganam M, Meng L, Lingwood CA. Oxidation
of glycosphingolipids under basic conditions: synthesis
of glycosyl "serine acids" as opposed to
"ceramide acids". Precursors for neoglycoconjugates
with increased ligand binding affinity. Biochemistry,
38: 10885-10897, 1999.
Mylvaganam M, Lingwood CA. A convenient oxidation
of natural glycosphingolipids to their "ceramide
acids" for neoglycoconjugation. Bovine serum
albumin-glycosylceramide acid conjugates as investigative
probes for HIV gp120 coat protein-glycosphingolipid
interactions. Journal of Biological Chemistry,
274: 20725-20732, 1999.
Arab S, Rutka J, Lingwood CA. Verotoxin induces
apoptosis and the complete, rapid, long-term elimination
of human astrocytoma xenografts in nude mice. Oncology
Research, 11: 33-39, 1999.
Arab S, Lingwood CA. Intracellular targeting
of the endoplasmic reticulum-nuclear envelope by retrograde
transport may determine cell hypersensitivity to verotoxin
via globotriaosyl ceramide fatty acid isoform traffic.
Journal of Cellular Physiology, 177: 646-660, 1998.
Nyholm PG, Magnusson G, Zheng Z, Norel R, Binnington-Boyd
B, Lingwood CA. Two distinct binding sites
for globotriaosyl ceramide on verotoxins: identification
by molecular modelling and confirmation using deoxy
analogues and a new glycolipid receptor for all verotoxins.
Chemistry and Biology, 3: 263-275, 1996.
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