Adoptively transferred LPS-treated BMDCs effectively migrated to
the lungs
The function of DCs is intimately associated with their capacity to
migrate to target organs20. It was previously
demonstrated that the onset of tolerance in DC10-treated asthmatic mice
is progressive; thus, airway hyperresponsiveness (AHR) in mice is mildly
attenuated at 2 weeks after transfer and vanishes entirely within 3
weeks4. To examine when and whether the injected DClps
could successfully migrate to the lungs, we established a mouse model of
asthma and treated asthma model mice with diverse DCs that were primed
under different conditions. We used the fluorescent dye PHK26 as a
marker for the trafficking of transferred DCs in vivo in treated mice,
and mice were sacrificed on days 1, 3, and 7. One day after transfer,
DClps
labeled with PHK26 appeared in the lungs, with a modest proportion of
the labeled cells (2.26%; absolute BMDCs is 396.). In contrast to DCia
with 1.08% (144 cells total), saline control with 0.188% (35 cells
total) (p<0.05). On day 3, the proportion of all DCs labeled
with PHK26 peaked in the lungs, among which DClps increased the most
markedly, representing 5.42% of the labelled BMDCs, compared to 1.52%,
0.98% in DCia and saline group (p<0.05). However, the number
of DClps strikingly decreased on day 7 (0.628%, absolute cell number
82). No detectable difference was found among three groups
(p>0.05).
These data indicate that DClps migrated to the lungs more effectively
and gradually accumulated in the lungs within 1 week. Moreover, the
decreased percentage of DClps in the lungs was consistent with the
alleviation of lung inflammation in asthmatic mice, which further
confirmed that DClps may effectively migrate to the lungs and take
effect within 1 week.