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dc.contributor.authorGaekwad, Jidnyasa
dc.date.accessioned2014-03-04T18:18:56Z
dc.date.available2014-03-04T18:18:56Z
dc.date.issued2009-08
dc.identifier.othergaekwad_jidnyasa_200908_phd
dc.identifier.urihttp://purl.galileo.usg.edu/uga_etd/gaekwad_jidnyasa_200908_phd
dc.identifier.urihttp://hdl.handle.net/10724/25804
dc.description.abstractOrganic & Biomolecular Chemistry Abstract: Tetra-acylated lipid As derived from Porphyromonas gingivalis LPS have been synthesized using a key disaccharide intermediate functionalized with levulinate (Lev), allyloxycarbonate (Alloc) and anomeric dimethylthexylsilyl (TDS) as orthogonal protecting groups and 9-fluorenylmethoxycarbamate (Fmoc) and azido as amino protecting groups. Furthermore, an efficient cross-metathesis has been employed for the preparation of the unusual branched R-(3)-hydroxy-13-methyltetradecanic acid and (R)-3 hexadecanoyloxy-15-methylhexadecanoic acid of P. gingivalis lipid A. Biological studies have shown that the synthetic lipid As cannot activate human and mouse TLR2 and TLR4 to produce cytokines. However, it has been found that the compounds are potent antagonist of cytokine secretion by human monocytic cells induced by enteric LPS. Nature Chemical Biology Abstract:The overexpression of saccharides such as Globo-H, LewisY and Tn antigen is a common feature of oncogenic transformed cells. Endeavors to exploit this aberrant glycosylation for cancer vaccine development have been complicated by difficulties in eliciting high titers of IgG antibodies against classical conjugates of tumor-associated carbohydrates to carrier proteins. We have designed, chemically synthesized and immunologically evaluated a number of fully synthetic vaccine candidates to establish strategies to overcome the poor immunogenicity of tumor-associated carbohydrates and glycopeptides. We have found that a three-component vaccine composed of a TLR2 agonist, a promiscuous peptide T-helper epitope and a tumor-associated glycopeptide can elicit in mice exceptionally high titers of IgG antibodies that can recognize cancer cells expressing the tumor-associated carbohydrate. The superior properties of the vaccine candidate are attributed to the local production of cytokines, upregulation of costimulatory proteins, enhanced uptake by macrophages and dendritic cells and avoidance of epitope suppression.
dc.languageeng
dc.publisheruga
dc.rightspublic
dc.subjectlipid A
dc.subjectcytokine
dc.subjectcancer vaccine
dc.titleModulation of toll-like receptor responses with synthetic ligands and its application to vaccine design
dc.typeDissertation
dc.description.degreePhD
dc.description.departmentChemistry
dc.description.majorChemistry
dc.description.advisorGeert Jan Boons
dc.description.committeeGeert Jan Boons
dc.description.committeeLance Wells
dc.description.committeeMichael Tiemeyer


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