A dynamic map of antigen recognition by CD4 T cells at the site of Leishmania major infection.
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.
Filipe-Santos
Orchidée
O
Institut Pasteur, G5 Dynamiques des Réponses Immunes, Inserm U668, Equipe Avenir, Paris F-75724, France.
Pescher
Pascale
P
Breart
Béatrice
B
Lippuner
Christoph
C
Aebischer
Toni
T
Glaichenhaus
Nicolas
N
Späth
Gerald F
GF
Bousso
Philippe
P
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
D000953:Antigens, Protozoan