HIV and Mature Dendritic Cells: Trojan Exosomes Riding the Trojan Horse? (original) (raw)
Figure 4
Capture and transfer of HIV-1 particles by mDCs converges with the exosome-dissemination pathway.
(A) Binding. Electron microscopy images of mDCs simultaneously pulsed with HIVNL43 and Jurkat-derived exosomes. Particles displaying viral morphology (with an electro-dense core; green arrows) or exosome morphology (with lighter core; red arrows) accumulated in the same area of the membrane. (B) Capture. Left. Electron microscopy as in (A), showing HIVNL43 and Jurkat-derived exosome accumulation within the same vesicles. Middle. Confocal images of a section of an mDC exposed to HIVvpr-eGFP/NL43 and Jurkat-derived exosomes labeled with DiI for 4 h and stained with DAPI. Top images show the mDC, where the red and green fluorescence merged with DAPI either with or without the bright field cellular shape are presented. Bottom images show magnification of vesicles containing these particles where individual green and red fluorescence and the combination of both are depicted. Right. Confocal microscopy analysis of an mDC pulsed simultaneously with HIV Gag-eGFP VLPs and Jurkat-derived exosomes labeled with DiI and then stained with DAPI. Composition of a series of x-y sections of an mDC collected through part of the cell nucleus and projected onto a two-dimensional plane to show the x-z plane (bottom) and the y-z plane (right). (C) Transfer. Infectious-like synapses could also be observed in co-cultures where mDCs were previously pulsed either with HIV Gag-eGFP VLPs (Top) or Jurkat-derived exosomes labeled with DiI (Bottom), extensively washed, and then allowed to interact with Jurkat CD4+ T cells. Images shown, from left to right, depict the red and green fluorescence channels merged with DAPI, the bright field cellular shape, and the combination of both.