Visualizing T cell migration in vivo.
Ever since the realization that T lymphocytes are key players in the defense against pathogens and tumors, a major aim of immunologists has been to understand the relationship between the functional and migratory properties of antigen-specific T cells. The current paradigm proposes that T cells follow organ-specific trafficking pathways to exit from blood into the extravascular compartment. T cell homing is regulated at the level of adhesion molecules and chemokine receptors, whose expression is linked tightly to the differentiation state of the cell. Naïve T lymphocytes follow relatively uniform recirculation routes through secondary lymphoid organs, the molecular cues of which are fairly well understood. As effector and memory T cells must be capable of reaching virtually any site in the body, their migratory behavior is considerably more heterogeneous. During the past few years, innovative approaches for tracking T cells in vivo have emerged. Here, we review recent technical developments in experimental methods for the visualization of T cells both at the population and single cell level in vivo, and discuss what these methods have taught us about T cell trafficking.
Iparraguirre
Amaya
A
CBR Institute for Biomedical Research and Department of Pathology, Harvard Medical School, Boston, Mass., USA.
Weninger
Wolfgang
W
D000818:Animals; D002465:Cell Movement / Q000276:immunology*; D007158:Immunologic Techniques; D008163:Luminescent Measurements; D008279:Magnetic Resonance Imaging / Q000379:methods; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods; D013601:T-Lymphocytes / Q000276:immunology*; D014055:Tomography, Emission-Computed / Q000379:methods