Minimal activation of memory CD8+ T cell by tissue-derived dendritic cells favors the stimulation of naive CD8+ T cells.
Of the many dendritic cell (DC) subsets, DCs expressing the monomorphic coreceptor CD8 alpha-chain (CD8alpha) are localized permanently in lymphoid organs, whereas 'tissue-derived DCs' remain in nonlymphoid tissues until they 'capture' antigen and then move to local lymph nodes. Here we show that after lung infection, both naive and memory CD8+ 'killer' T cells responded to influenza virus antigens presented by lymph node-resident CD8alpha+ DCs, but only naive cells responded to antigens presented by lung-derived DCs. This difference provides a mechanism for priming naive T cell responses in conditions in which robust memory predominates. Our findings have implications for immunity to pathogens that can mutate their T cell epitopes, such as influenza virus and human immunodeficiency virus, and challenge the long-held view that memory T cells have less-stringent requirements for activation than naive T cells have.
Belz
Gabrielle T
GT
Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia. belz@wehi.edu.au
Bedoui
Sammy
S
Kupresanin
Fiona
F
Carbone
Francis R
FR
Heath
William R
WR
D000818:Animals; D053282:CD27 Ligand / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D007156:Immunologic Memory; D008168:Lung / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice
D053282:CD27 Ligand