CCL25 Expression In The Oral Mucosa

Objective: To determine whether CCL25 plays a role in the migration of T lymphocytes and IgA plasma cells into the oral mucosa. 

Methods: An ACIS III scanner was used to quantify immunohistochemical staining of CCL25, CD3 and IgA in normal (NOM) and diseased oral mucosa and the results shown as expression index (EI= % of +ve cells X staining intensity).

Oral keratinocytes (OK) and the oral cancer cell line (H357) were treated with TNF-α and IL1-β and production of CCL25 measured by ELISA

Results:

-     Low levels of CCL25 were seen in the epithelial cells in NOM [2845.4(±673.7)] but significantly higher levels were evident in oral lichen planus [6646.3(±746.8)], chronic hyperplastic candidiasis (CHC) [8339.42(±295.4)] and oral squamous cell carcinoma with high host response [5453.7(±608.4)] (P<0.001). Levels were significantly down regulated in oral Crohn’s disease [159.0(±74.3)] (P<0.001).

-     CCL25 expression was directly correlated to the intensity of the T cell (CD3) (r=0.7) but not the IgA plasma cell infiltrate (r=0.1).

-     In vitro, OK contained high intracellular levels of CCL25 which showed an 11.7(±3.3) % increase following TNF-α/IL1-β stimulation (P< 0.01). There was no evidence of chemokine release.

Conclusion:

• CCL25 production is not restricted to the gut but is also found in oral epithelium and levels are raised in disease
• CCL25 may play a role in the migration of T cells but not IgA plasma cells into the oral mucosa.
• Further work is required to determine what controls CCL25 release from epithelial cells.