Sugar Specific Delivery of Drugs, Oligonucleotides and Genes
Résumé
Many mammalian cells have plasma membrane proteins that are able to both selectively bind macromolecules containing a recognition signal and mediate the transfer of such macromolecules to the endosomal compartments. Amongst the various receptors known so far, there are membrane lectins that selectively recognize glycoconjugates containing complex oligosaccharides structures (Goldstein et al, 1980). In mammalian cells, lectins are either secreted water soluble proteins or proteins present in both the cytosol and the nucleus (see for reviews Hubert et al, 1989; Hart et al, 1989; Wang et al, 1991). Other lectins are type I or type II membrane proteins. The first membrane lectin was discovered 25 years ago by G. Ashwell and A. Morell and their coworkers (for a review, see Ashwell and Harford, 1982). The first evidence came from an experiment using asialoceruloplasmin: ceruloplasmin is a serum protein carrying copper ions, it is a glycoprotein which has a long lifetime in the blood; however, upon desialylation, the asialoglycoprotein is cleared off from the serum in a few minutes because it is captured in the liver by parenchymal cells (Morell et al, 1971).