Identifying homing interactions in T-cell traffic in human disease

Description of the molecular mechanisms which regulate the traffic of lymphocyte populations over recent years [for useful reviews see (1, 2)] has significantly enhanced our understanding of the processes underlying acquired immunity and also permitted the development of therapies targeted at specific leukocyte subpopulations. Such therapies are dependent upon a detailed knowledge of the molecular regulation of lymphocyte adhesion to and migration through endothelium in specific tissues. Whereas animal models have been central to understanding the underlying mechanisms, it is crucial to confirm and extend observations in man by using analysis of tissues and in vitro cell-based models. In this chapter, we discuss expertise developed in our laboratory for the isolation of specific lymphocyte and endothelial populations from explanted human liver tissue specimens. We then move on to provide specific examples of assays such as the Stamper-Woodruff assay, the transmigration assay and the tissue-specific endothelial static and flow-based adhesion assays, which can be used to interrogate the tissue-specific adhesion and migration of lymphocyte subsets. Although our own experience is with human liver tissue, the general principles apply to analysing any organ of interest.