In order to characterize the molecular mechanism of blister formation of oral mucosa in pemphigus vulgaris (PV), we observed the effects of PV serum on the arrangement of keratin intermediate filaments (KIFs) and desmosomes of cultured human gingival keratinocytes by transmission electron microscope.
The arrangement of KIFs in contol cells showed a radiating pattern of filament bundles to the cell periphery, and these bundles ended at well developed desmosomes.After incubation with PV serum for 96 hrs at 37°C, the arrangement of bundles of KIFs became unclear and the number of desmosomes decreased, and amorphous dotted structures were observed.
These dotted structures seemed to be formed by structural changes of KIFs and these structures were often associated with distrupted desmosomes.These results support our hypothesis that PV serum induces structural changes in KIFs and also in desmosomes.