Faithin Omaha eBook Collection

Download or read book New Carbohydrate-based Anti-cancer and Anti-bacterial Vaccines written by Zhifang Zhou and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique carbohydrates expressed on the surface of cancer, bacterial, viral and fungal cells are excellent target antigens for the design of therapeutic or preventive vaccines. However, as antigens carbohydrates have problems. First, carbohydrates usually have low immunogenicity. Second, even if immunogenic, carbohydrates typically elicit T cell-independent immune responses. To overcome these problems and design useful vaccines based on carbohydrate antigens, they are usually coupled with carrier proteins to form conjugates to enhance the immunogenicity of the antigens. However, there are still some issues existing in glycoprotein vaccines, such as poor reproducibility of the conjugates, difficulties in quality control and so on. To deal with these issues, our group explored a strategy to utilize synthetic carbohydrate antigens with well-defined structures for the construction of glycoprotein vaccines. In the meantime, our group has also developed new vaccine carriers, such as monophosphoryl lipid A (MPLA), to construct full-synthetic carbohydrate-based vaccines that have well-defined structures and improved immunological properties. The main aims of this dissertation are to study and evaluate these semi- and full-synthetic glycoconjugates and develop carbohydrate-based vaccines against cancer and bacteria. The first part of this dissertation (Chapters 2 and 3) is focused on antitumor vaccines targeting at tumor-associated carbohydrate antigens (TACAs). For TACAs, in addition to the problems associated with carbohydrate antigens mentioned above, there is another problem, namely immunotolerance, due to their structural similarity to normal carbohydrates on normal cells. To overcome the immunotolerance problem, our group developed a novel immunotherapeutic strategy based on glycoengineering of sialo-TACAs on cancer cells. An important requirement for this strategy to work is to engineer cancer cells to express unnatural sialo-TACAs.