Immune mechanisms of sublingual immunotherapy: Are oral Langerhans cells the masters of tolerance?

[...]approximately 80% of all CD1a+ cells in the tissue had migrated into the culture medium, despite the fact that only 40% of these cells stained positive for allergen binding. Because a similar rate of migration over time was observed in control cultures (PBS, allergen at 4°C, and FITC-labeled dextran), it can be concluded that the time-dependent increase in migrated CD1a+ cell numbers was a nonspecific phenomenon, whereas the increased number of cells at each time point (37°C) was an allergen-specific finding. [...]perhaps most intriguingly, does the downregulation of CCR7 on migrating oLCs suggest that local antigen presentation occurs outside draining lymphoid tissue, thereby perhaps enhancing tolerogenic interactions?