title: Thymic but not splenic CD8⁺ DCs can efficiently cross-prime T cells in the absence of licensing factors.
abstract: Cross-presentation is an important mechanism to elicit both immune defenses and tolerance. Although only a few DC subsets possess the machinery required for cross-presentation, little is known about differences in cross-presenting capabilities of DCs belonging to the same subpopulation but localized in different lymphoid organs. In this study, we demonstrate that steady-state thymic CD8(+)  DCs can efficiently cross-prime naïve CD8(+)  T cells in the absence of costimulation. Surprisingly, cross-priming by splenic CD8(+)  DCs was dependent on licensing factors such as GM-CSF. In the absence of GM-CSF, antigen-MHC-class-I complexes were detected on thymic but not on splenic CD8(+)  DCs, indicating that the cross-presentation capacity of the thymic subpopulation was higher. The observed cross-priming differences between thymic and splenic CD8(+)  DCs did not correlate with differential antigen capture or costimulatory molecules found on the surface of DCs. Moreover, we did not detect overall impairment of antigen presentation, as peptide-loaded splenic CD8(+)  DCs were able to induce CD8(+)  T-cell proliferation. The observation that thymic CD8(+)  DCs are more efficient than splenic CD8(+)  DCs in T-cell cross-priming in the absence of licensing factors indicates that the requirements for efficient antigen presentation differ between these cells.
authors: Institute of Virology, University of Zurich, Zurich, Switzerland. cdresch@vetvir.uzh.ch
authors: Christiane
authors: C
authors: Dresch
authors: Mathias
authors: M
authors: Ackermann
authors: Bernd
authors: B
authors: Vogt
authors: Bruna
authors: B
authors: de Andrade Pereira
authors: Ken
authors: K
authors: Shortman
authors: Cornel
authors: C
authors: Fraefel
mesh_terms: D000818:Animals; D016827:CD8 Antigens / Q000096:biosynthesis; D049109:Cell Proliferation; D002478:Cells, Cultured; D045142:Cross-Priming; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009928:Organ Specificity; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I; D016178:Granulocyte-Macrophage Colony-Stimulating Factor