Immune Cell Variability in Human Filiform Tongue Papillae

Radiation to head and neck cancers routinely effects taste loss and alteration of food-flavor perception, quickly impairing food intake and leading to malnutrition and 'failure to thrive'. While taste cells regenerate throughout normal aging, extensive radiation may require years of recovery. Chronic radiotherapy insult may produce histopathological changes and genetic alteration of epithelial/gustatory regenerative cellular processes.

Objectives: To establish baseline cell populations, we identified immune cells in normal human fungiform papillae. Current work further identifies histochemical variability in healthy epithelia examined for dendritic cells, macrophages, and lymphocytes.

Methods: We stained multiple fungiform papillae from healthy subjects (40-50 yrs old) by indirect immunohistochemistry to identify surface protein CD cell markers. Cell counts further quantitated CD populations.

Results: Variability in stained cells for each immunohistochemical test resulted in phenotypic differences in papilla from the same individuals. CD11c+ dendritic cells were more prevalent than CD64+ macrophages, mature (CD83+) and immature (CD209+) dendritic cells had similar density. T lymphocytes (CD3, CD4, and CD8) were more prevalent than B lymphocytes (CD19+), and CCR5+ Th1 cells were more prevalent than CCR4+ Th2 cells among lymphocytes. Submucosal tissue depth correlated with greater numbers of stained cells.

Conclusions: Immune cell profiles play a central role in oral mucosa barrier functions and characteristics of cross-sectioned papilla establish a trend correlating submucosa depth and stained cell populations. These data further establish protocol for the study of epithelial damage subsequent to radiotherapy to gustatory fields with potential for taste loss. Immune cell distribution and variability may be critically significant in the correlation of cellular changes with perceptions of taste and definition of subclinical taste abnormalities. Appreciation of phenotypic variation may allow direction of clinical intervention to minimize inflammatory sequellae in patients at risk for taste loss.

Support: NIH DC00214.