Loss of Langerhans cells from gingival tissue maintained in organ culture

Abstract

Changes occurring in a population of Langerhans cells (LC) were investigated using human gingival epithelium maintained in organ culture. The enzyme adenosine 5′‐triphosphatase together with the surface antigens HLA‐DR and T6 were used to identify and quqntitate these cells. An exponential fall in the expression of each of these markers was seen to occur with increasing incubation lime, suggesting that a true loss of these cells is in fact occurring. HLA‐DR antigen is shed from LC at a rate significantly greater than thai al which LC are lost. A mathematical model which simulates the behaviour of LC within organ culture is presented, and several implications and possible explanations proposed.

Modulation of Langerhans cell surface antigen expression by recombinant cytokines

“…The relationship between cytokines which induce CDla expression is worthy of note, Keratinocytes synthesize IL-1, TNF-a and IL-6, and exposure of keratinocytes to one of these three mediators induces the synthesis and release of the remaining two cytokines (26)(27)(28)(29). However, unlike TNF-a and IL-6, IL-1 does not induce HLA-DR expression on LC (31), IL-1 directly stimulates dendritic cells, including LC (1,31,32), and specific inhibitors of IL-1 block the induction of CDla expression by IL-1 (19,20,30), Taken together, these results suggest that induction of IL-1 secretion by keratinocytes Table 2. Effect of eytokines on antigen expression by cultured gingival Langerhans eells.…”

“…The results of the present study indicate that cytokines modulate antigen expression by gingival LC, and may stimulate or suppress according to the mediator used. Like IL-1 (7,20), TNF-a and IL-6 upregulate CDla expression. The finding that the CDla+cell density in cultures treated with TNF-a or IL-6 exceeded that of pre-incubation explants suggests that expression of CDla on CDla" LC precursors is induced by these mediators, as previously described for IL-1 (See 19 for review).…”

“…The method used was that previously described in detail (20), In brief, human gingival tissue was obtained during periodontal surgery. Patient consent to use tissue which would normally be discarded during surgery was obtained with the approval of the institutional ethics committee.…”

Gingival organotypic culture and langerhans cells: A tool for immunotoxicologic experiments

“…21 Skin cultures can be maintained in Ham's F12/DMEM medium for a week with no signs of alteration 22 while superficial plaques of epithelial necrosis begin to appear after 2 days on gingival explants. 23 This indicates that oral mucosal tissues are more demanding in terms of culture conditions. There also is a difference in functional capacity between Langerhans cells in oral and skin epithelia.…”

Differential expression of Class II (DR & DQ) antigens by human gingival Langerhans' cells and keratinocytes in vitro

“…Henee, the ptesent study was uiidcttaken to investigate further the expression of DO by gingival LC, specifically the inl'luenee of bacterial produets on DO expression //; vitro. l'\ir this putpose gingival organ ctilture (9) was used.…”