| Adhesion of leukocytes to the vessel wall plays a significant role in inflammation. This adhesion is mediated by adhesion molecules present on the vessel wall (the endothelium) and leukocytes. E-selectin is an important receptor in the adhesion process. Both leukocyte expressed P-selectin Glycoprotein Ligand-1 (PSGL-1) and Sialyl Lewis x (SLex) glycans can support adhesive interactions to E-selectin. PSGL-1 and SLex may give arise to different types of adhesive interactions. This motivated an investigation into ligand biochemistry in E-selectin adhesion. The results showed that PSGL-1 is a highly efficient ligand for E-selectin compared to SLex, which indicates that ligand biochemistry plays a significant role in the initial tethering to E-selectin. Evidence that non-HECA-452 antigens are involved in PSGL-1 tethering to E-selectin is also provided.;To gain further insight into the adhesion study, in Chapter 3, the probability of initial tethering of particles delivered onto the substrate in the parallel plate flow chamber adhesion assay was determined. The results indicate that the probability of initial tethering of PSGL-1 microspheres is much higher than SLex microspheres, which strongly suggests, again, that PSGL-1 is a better tethering ligand than SLex.;Together, these studies provide further understanding of E-selectin and its important ligands PSGL-1 and SLex. |
