Synthesis of selected fragments of the Lewis B Lewis A Tumor-Associated Carbohydrate Antigen
Carbohydrates are the most abundant class of natural products found in living organisms. They are present on the surface of cells and play a vital role in cell recognition. It has been observed that tumor cells overexpress some oligosaccharides on their surface. These oligosaccharides have been named Tumor-Associated Carbohydrate Antigens (TACA). One TACA of interest to our research group is the LebLea heptaasaccharide, which is displayed on the surface of liver, pancreas and endometrium carcinomas. Carbohydrates are immunogenic, therefore, it is possible to design a carbohydrate-based vaccine against these tumor cells. However, an immune response against LebLea would likely result in an auto-immune response as Leb is found on healthy cells. If a fragment of LebLea is used instead, it is quite possible that an immune response is raised against LebLea while being harmless to normal healthy cells. This thesis describes the synthesis of tri- tetra- and pentasaccharide fragments of LebLea. The synthesized fragments can then be subjected to immunochemical studies to test for cross-reactivity. Successful results may lead to a potential carbohydrate based anticancer vaccine for the proposed TACA LebLea.