B. Hasseus et al., Langerhans cells from oral epithelium are more effective in stimulating allogeneic T-cells in vitro than Langerhans cells from skin epithelium, J DENT RES, 78(3), 1999, pp. 751-758
Dendritic cells, such as Langerhans cells (LC), in different ectodermal com
partments may have different functional capabilities. The present study was
undertaken to compare oral Langerhans cells (LC) with those of the epiderm
is in terms of their ability to co-stimulate T-cells in vitro. A Mixed Epit
helial Cell Lymphocyte Reaction (MELR) and a mitogen-driven (concanavalin A
) T-cell proliferation assay were used. In both assays, LC in a crude cell
suspension of freshly isolated oral epithelial cells were found to be five
times more effective in mediating T-cell proliferation than freshly isolate
d epidermal LC. Twenty-four-hour cell culture at 37 degrees C enhanced the
T-cell response in the MELR compared with cells cultured at 4 degrees C. Th
is applied to both skin and oral epithelial cells. Oral and skin epithelial
cell suspensions depleted of LC lost the capacity to stimulate allogeneic
T-cells. Incubation of the epithelial cell suspensions with recombinant Gra
nulocyte/Macrophage-Colony Stimulating Factor (rGM-CSF) did not enhance the
co-stimulating capacity of the LC. Titration of different numbers of oral
and skin LC to T-cells showed that skin LC were never able to reach more th
an 44% of the maximal stimulatory capacity of oral LC. Data show that oral
LC are more efficient than skin LC in providing co-stimulatory signals to T
-cells, suggesting a difference in functional capacity between the two cell
populations.