TLR agonists induce regulatory dendritic cells to recruit Th1 cells via preferential IP-10 secretion and inhibit Th1 proliferation

C Qian, H An, Y Yu, S Liu, X Cao - Blood, 2007 - ashpublications.org
C Qian, H An, Y Yu, S Liu, X Cao
Blood, 2007ashpublications.org
Dendritic cells (DCs) and chemokines are important mediators linking innate and adaptive
immunity on activation by Toll-like receptor (TLR) agonists. We previously identified a kind of
regulatory DC subset (diffDCs) that differentiated from mature DCs under splenic stroma and
that inhibited T-cell proliferation. The responsiveness of such regulatory DCs to TLR
agonists and their pattern of chemokine production remain to be determined. Here, we
report that the regulatory DCs secrete a higher level of CXCR3 chemokine IFN-γ–induced …
Abstract
Dendritic cells (DCs) and chemokines are important mediators linking innate and adaptive immunity on activation by Toll-like receptor (TLR) agonists. We previously identified a kind of regulatory DC subset (diffDCs) that differentiated from mature DCs under splenic stroma and that inhibited T-cell proliferation. The responsiveness of such regulatory DCs to TLR agonists and their pattern of chemokine production remain to be determined. Here, we report that the regulatory DCs secrete a higher level of CXCR3 chemokine IFN-γ–induced protein-10 (IP-10) than immature DCs (imDCs), and more IP-10 is produced after stimulation with TLR-2, -4, -3, and -9 ligands. Blockade of IFN-α/β inhibits IP-10 production by TLR agonist-activated regulatory DCs. We show that the increased IRF-3 and IFN-β–induced STAT1 activation are responsible for the autocrine IFN-β–dependent preferential production of IP-10 by regulatory DCs. In addition, stimulation with recombinant mouse IFN-α/β induces more IP-10 production in regulatory DCs than that in imDCs. Moreover, the regulatory DCs selectively recruit more Th1 cells through IP-10 and inhibit Th1 proliferation. Our results demonstrate a new manner for regulatory DCs to down-regulate T-cell response by preferential IP-10 production and inhibition of recruited Th1 cell proliferation.
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