How immune cells find their targets: Quantitative studies of cell adhesion, migration, and chemotaxis

This chapter outlines the quantitative analysis of the processes of cell adhesion, migration, and chemotaxis, and their effects on the rates of encounter between immune cells and their targets. The results should prove to be helpful in improving theoretical understanding of the dynamics of the immune response. It is becoming increasingly clear that the immune response is essentially based on cell-cell interactions requiring direct contact between different cells. Theoretical understanding of the dynamics of the immune response will require corresponding understanding of the cellular processes underlying cell/target encounter. An immune cell in a microcirculatory vessel approaches the vessel endothelium under conditions of low Reynolds number fluid shear flow. Adhesion requires formation of a number of bonds between specific cell “receptor” macromolecules and endothelial surface “ligand” macromolecules sufficient to resist the distractive forces on the cell. The various classes of white blood cells have been shown to be capable of migration on two-dimensional substrates and through three-dimensional matrices.