ISSN:
1365-2133
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Ultrastructural changes of murine Langerhans cells (LC) were examined following exposure of crude epidermal cell suspensions to the contact allergens dinitrochlorobenzene, nickel sulphate and lead nitrate at various concentrations and for various incubation times. An immunogold labelling technique was employed to study changes in surface expression of MHC Class II (Ia) molecules. In all cases, activation of LC was evident after as little as 15 min exposure and was characterized by a marked increase in surface expression of Ia molecules, prominent rough endoplasmic reticulum and numerous ribosomes and lysosomes. Degenerative changes in LC were apparent to varying degrees depending on the allergen, its concentration and the time of incubation. Degenerative changes included swollen mitochondria, membrane disruption or rupture, loss of density of the cytoplasm (cytolysis), loss of dendritic processes and decreased expression of Ia molecules. In the case of dinitrochlorobenzene, degenerative changes were present and usually severe at concentrations greater than 10 μg/ml, while exposure to nickel sulphate and lead nitrate was associated with only mild degenerative changes, These observations indicate that contact allergens have a variety of direct effects on LC, including activation and degeneration, which are dose- and time-dependent. Since these alterations of LC were observed in the absence of other immunologically active cells, peripolesis cannot be involved in these events.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2133.1987.tb04895.x
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