Characterization of the adhesion between specific RBC surface receptors and ligands in SCD

AFM has emerged as a powerful tool to measure the forces within or between single biomolecules. In particular, functionalization of the AFM tip with ligands has allowed for mapping the distribution of complementary receptors on model or cellular surfaces, a technique known as single-molecule force spectroscopy (SMFS). It has been suggested that vaso-occlusive sequelae of SCD arise in part from an increase in adhesive interactions between sickle RBCs and the endothelium. RBC membrane proteins known to be involved in mediating the interaction between SCD erythrocytes and the endothelium include: basal cell adhesion molecule/Lu (BCAM/Lu, CD239); integrin associated protein (CD47); CD147; intercellular adhesion molecule-4 (ICAM-4, the protein bearing the LW blood group antigens). We intend to employ SMFS to map the distribution and quantify the affinity of the ligand-receptor complexes listed above.