Biology Reference
In-Depth Information
As shown in Figure 4A, and independently of the TPL source, a minimal time
period of 30 min was required for ARC uptake by phagocytic cells, as judged by the
detection of intracellular fl uorescence after incubation with both ARC-HPTS/DPX. In
addition, J-774 macrophages incubated 45 min with both ARC-HPTS/DPX showed
punctual fl uorescence (as shown by arrows in Figure 4A) that resulted from the con-
fi nement of the HPTS/DPX into vesicular compartments in the cytoplasm. In case
membrane fusion between ARC and the phagosome occurred, the ARC inner content
should be released to the cytoplasm. Consequently, the HPTS would be dequenched
from DPX and an homogeneous brightness fi lling the cytoplasm should be observed
[20, 21]. However, the punctual emission upon excitation at 440 nm, indicating con-
fi nement of the pair HPTS/DPX in acidic compartments, remained unchanged. Hence,
the ARC did not fuse/disrupt, staying inside the phagosomes for at least 60 min
(Figure 4B).
Figure 4.
(A) Fluorescence microscopy images of J-774 cells upon 30 min incubation with ARC-
BM
-HPS/DPX. (B) Intracellular distribution of HPTS in green vesicles persistent 60 min after uptake.
Antibody Response
To evaluate the adjuvant activity of both ARC formulations, we tested the antigen-spe-
cific humoral immune response after immunization of mice with BSA-loaded ARC.
Following sc inoculations at 0 and 21 days, mice responded by day 28 with similar
anti-BSA antibody (total IgG) titers for both ARC-
BM
/
GC
-BSA (Figure 5A), and pre-
sented a strong enhancement (~2 log,
p
< 0.01) of antibody titers over those of BSA
