APPROACHES TO THE STUDY OF GLYCOLIPID BIOCHEMICAL MECHANISMS OF ACTION

With this work I want to give an explanation of the role of glycolipids in biological processes, paying particular attention to their involvement in various biochemical mechanisms. This thesis will be divided into two sections in which I discuss in the first one, the involvement of glycolipids in the process of fertilization and in the second one I will pay attention on a new class of glycolipids that might be involved in immunoregulation processes. In more details in the first section I will provide an overview of the biochemical role of sulfogactosylglicerolipid (SGG), present in the sperm head of different mammalian species, and its involvement in the process of fertilization. Then I will discuss an approach with which one can interfere in this biochemical mechanism focusing on the possibility of using a new class of molecules that permit not only the inhibition of the fertilization process but that can also act against sexually transmitted diseases. In this scenario, then I will focus on the characteristics of antimicrobial peptides, in particular on the family of cathelicidin, and on their possible application in the inhibition of fertilization, by interaction with SGG, and at the same time the prevention of sexually transmitted diseases. In the second section I will discuss on a new class of immunomodulating glycolipids with an atypical structure, produced by symbiotic bacteria in the marine sponge Plakortis Simplex, which releases a unique profile of cytokines. In this scenario, then I will talk about simplexide and on the role in which is involved in the activation of peripheral blood mononuclear cells (PBMC), and the peculiar profile of cytokines released. Then I will describe the synthesis of a fluorescent analogue of simplexide which will be made to evaluate the subcellular distribution of the glycolipid and to clarify its mechanism of action.