Alternative cross-priming through CCL17-CCR4-mediated attraction of CTLs toward NKT cell–licensed DCs

V Semmling, V Lukacs-Kornek, CA Thaiss, T Quast… - Nature …, 2010 - nature.com
V Semmling, V Lukacs-Kornek, CA Thaiss, T Quast, K Hochheiser, U Panzer, J Rossjohn
Nature immunology, 2010nature.com
Cross-priming allows dendritic cells (DCs) to induce cytotoxic T cell (CTL) responses to
extracellular antigens. DCs require cognate'licensing'for cross-priming, classically by helper
T cells. Here we demonstrate an alternative mechanism for cognate licensing by natural
killer T (NKT) cells recognizing microbial or synthetic glycolipid antigens. Such licensing
caused cross-priming CD8α+ DCs to produce the chemokine CCL17, which attracted naive
CTLs expressing the chemokine receptor CCR4. In contrast, DCs licensed by helper T cells …
Abstract
Cross-priming allows dendritic cells (DCs) to induce cytotoxic T cell (CTL) responses to extracellular antigens. DCs require cognate 'licensing' for cross-priming, classically by helper T cells. Here we demonstrate an alternative mechanism for cognate licensing by natural killer T (NKT) cells recognizing microbial or synthetic glycolipid antigens. Such licensing caused cross-priming CD8α+ DCs to produce the chemokine CCL17, which attracted naive CTLs expressing the chemokine receptor CCR4. In contrast, DCs licensed by helper T cells recruited CTLs using CCR5 ligands. Thus, depending on the type of antigen they encounter, DCs can be licensed for cross-priming by NKT cells or helper T cells and use at least two independent chemokine pathways to attract naive CTLs. Because these chemokines acted synergistically, this can potentially be exploited to improve vaccinations.
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