Our body’s acute inflammatory response is partially characterized by the role of the leukocytes in the cascade of events. The leukocytes adhere to the blood vessel wall, perfuse through the wall to the site of the foreign agent within the tissue, and begin activation to destroy the agent, restoring the tissue to normal. The initial stage in that inflammatory response is the slowing down of the leukocytes as they flow in the blood stream in order for a firm adhesion to occur and allow perfusion. The molecules responsible for slowing down the leuckocytes are called selectins. Selectins form temporary adhesions with the cell forming tethers and causing it to roll along the endothelium until the integrins form a firm adhesion with it. Our research focuses on understanding the dynamics of the adhesion process of selectin molecules.
Of the several methods used to study selectins, we will be using flow chambers to observe the adhesion process under shear flow. The two flow chambers that will be used are: (1) inverted flow chamber and (2) side view flow chamber. In addition, there are three known types of selectins: P-, E-, and L-selectin. P-selectin (CD62P) is expressed on endothelial cells and platelets, E-selectin (CD62E) is also found on endothelial cells and L-selectin (CD62L) is expressed on leukocytes. With the inverted flow chamber, we will be able to look at the lifetime of rolling adhesion of leukocytes on the various selectins and obtain their kinetic rate information. The side view flow chamber will be used to more closely observe the tethering and rolling of leukocytes on selectin molecules.