title: A dynamic map of antigen recognition by CD4 T cells at the site of Leishmania major infection.
abstract: CD4 T helper cells play a central role in the control of infection by intracellular parasites. How efficiently pathogen-specific CD4 T cells detect infected cells in vivo is unclear. Here, we employed intravital two-photon imaging to examine the behavior of pathogen-specific CD4 T cells at the site of Leishmania major infection. While activated CD4 T cells enter the inflamed tissue irrespective of their antigen specificity, pathogen-specific T cells preferentially decelerated and accumulated in infected regions of the dermis. Antigen recognition by CD4 T cells was heterogeneous, involving both stable and dynamic contacts with infected phagocytes. However, not all infected cells induced arrest or deceleration of pathogen-specific T cells, and dense clusters of infected cells were poorly accessible to migrating T cells. Thus, disparities in the dynamics of T cell contacts with infected cells and local variation in T cell access to infected cells are important elements of the host-pathogen interplay.
authors.affiliation: Institut Pasteur, G5 Dynamiques des Réponses Immunes, Inserm U668, Equipe Avenir, Paris F-75724, France.
authors.forename: Orchidée
authors.initials: O
authors.lastname: Filipe-Santos
authors.forename: Pascale
authors.initials: P
authors.lastname: Pescher
authors.forename: Béatrice
authors.initials: B
authors.lastname: Breart
authors.forename: Christoph
authors.initials: C
authors.lastname: Lippuner
authors.forename: Toni
authors.initials: T
authors.lastname: Aebischer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Glaichenhaus
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Späth
authors.forename: Philippe
authors.initials: P
authors.lastname: Bousso
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000469:parasitology*; D054884:Host-Pathogen Interactions; D018320:Leishmania major / Q000276:immunology* / Q000472:pathogenicity; D007896:Leishmaniasis / Q000276:immunology* / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D013194:Staining and Labeling / Q000379:methods
chemical_list: D000953:Antigens, Protozoan