A dynamic map of antigen recognition by CD4 T cells at the site of Leishmania major infection

Cell Host Microbe. 2009 Jul 23;6(1):23-33. doi: 10.1016/j.chom.2009.04.014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Protozoan / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • Dendritic Cells / parasitology*
  • Host-Pathogen Interactions
  • Leishmania major / immunology*
  • Leishmania major / pathogenicity
  • Leishmaniasis / immunology*
  • Leishmaniasis / parasitology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microscopy, Confocal / methods
  • Microscopy, Fluorescence / methods
  • Staining and Labeling / methods

Substances

  • Antigens, Protozoan