title: Visualizing how T cells collect activation signals in vivo.
abstract: A decade ago the first movies depicting T cell behavior in vivo with the help of two-photon microscopy were generated. These initial experiments revealed that T cells migrate rapidly and randomly in secondary lymphoid organs at steady state and profoundly alter their behavior during antigen recognition, establishing both transient and stable contacts with antigen-presenting cells (APCs). Since then, in vivo imaging has continuously improved our understanding of T cell activation. In particular, recent studies uncovered how T cells may be guided in their search for the best APCs. Additionally, the development of more sophisticated fluorescent tools has permitted not only to visualize T cell-APC contacts but also to probe their functional impact on T cell activation. These recent progresses are providing new insights into how T cells sense antigen, collect activation signals during distinct types of interaction and integrate information over successive encounters.
authors.affiliation: Dynamics of Immune Responses Unit, Institut Pasteur, 75015 Paris, France; INSERM U668, 75015 Paris, France; Univ. Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, rue du Dr Roux, F-75015 Paris, France. Electronic address: helene.moreau@pasteur.fr.
authors.forename: Hélène D
authors.initials: HD
authors.lastname: Moreau
authors.affiliation: Dynamics of Immune Responses Unit, Institut Pasteur, 75015 Paris, France; INSERM U668, 75015 Paris, France. Electronic address: philippe.bousso@pasteur.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bousso
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D002450:Cell Communication / Q000276:immunology; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D036641:Microscopy, Fluorescence, Multiphoton; D008958:Models, Molecular; D011485:Protein Binding / Q000276:immunology; D011897:Random Allocation; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*