Spatiotemporal trafficking of HIV in human plasmacytoid dendritic cells defines a persistently IFN-α–producing and partially matured phenotype
Meagan O’Brien, … , David Levy, Nina Bhardwaj
Meagan O’Brien, … , David Levy, Nina Bhardwaj
Published February 21, 2011
Citation Information: J Clin Invest. 2011;121(3):1088-1101. https://doi.org/10.1172/JCI44960.
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Research Article Virology

Spatiotemporal trafficking of HIV in human plasmacytoid dendritic cells defines a persistently IFN-α–producing and partially matured phenotype

Abstract

Plasmacytoid DCs (pDCs) are innate immune cells that are specialized to produce IFN-α and to activate adaptive immune responses. Although IFN-α inhibits HIV-1 replication in vitro, the production of IFN-α by HIV-activated pDCs in vivo may contribute more to HIV pathogenesis than to protection. We have now shown that HIV-stimulated human pDCs allow for persistent IFN-α production upon repeated stimulation, express low levels of maturation molecules, and stimulate weak T cell responses. Persistent IFN-α production by HIV-stimulated pDCs correlated with increased levels of IRF7 and was dependent upon the autocrine IFN-α/β receptor feedback loop. Because it has been shown that early endosomal trafficking of TLR9 agonists causes strong activation of the IFN-α pathway but weak activation of the NF-κB pathway, we sought to investigate whether early endosomal trafficking of HIV, a TLR7 agonist, leads to the IFN-α–producing phenotype we observed. We demonstrated that HIV preferentially traffics to the early endosome in human pDCs and therefore skews pDCs toward a partially matured, persistently IFN-α–secreting phenotype.

Authors

Meagan O’Brien, Olivier Manches, Rachel Lubong Sabado, Sonia Jimenez Baranda, Yaming Wang, Isabelle Marie, Linda Rolnitzky, Martin Markowitz, David M. Margolis, David Levy, Nina Bhardwaj

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Figure 3

HIV-activated pDCs, like CpGA-activated pDCs, express lower levels of costimulatory molecules; however, all cells are refractory to inflammatory cytokine production upon restimulation, regardless of TLR agonist used.

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HIV-activated pDCs, like CpGA-activated pDCs, express lower levels of co...
(A) Maturation of pDCs after 18 hours induced by HIV AT-2, live HIV, CpGA, CpGB, influenza virus, or R848, as measured by CD86, CD40, and CCR7. Data are from 1 experiment, representative of 5 independent experiments. Dashed line is isotype control, dark gray histogram is unstimulated 18 hours, light gray histogram is stimulated with agonist. (B) Inflammatory cytokine production by HIV-activated pDCs versus comparator agonists, tested using cytometric bead array analysis. None of the agonists, including HIV, allowed for restimulation of inflammatory cytokines compared with initial stimuli (*P < 0.05, Student’s t test). Data are mean ± SEM (n = 3 replicates) and representative of 3 independent experiments. (C) Allogeneic T cell proliferation at day 6 after coculture with differentially matured pDCs, expressed as percent proliferation by CFSE. pDCs matured with HIV and CpGA stimulated T cell proliferation similar to that by unstimulated pDCs, whereas pDCs matured with CpGB, influenza virus, or anti-CD3/anti-CD28 stimulated significantly more T cell proliferation than did unstimulated pDCs (*P < 0.05, 2-tailed Student’s t test). Data are represented as mean ± SEM (n = 3 replicates) and representative of 4 independent experiments.