Distribution of carcinoembryonic antigen-related cellular adhesion molecules in human gingiva

Carcinoembryonic antigen-related cellular adhesion molecules (CEACAMs) are glycoproteins produced in epithelial, endothelial, lymphoid, and myeloid cells. Carcinoembryonic antigen-related cellular adhesion molecules mediate cell-cell contact and host-pathogen interactions. The aims of this study were to map the distribution and examine the regulation of CEACAMs in human gingival sites. Quantitative real-time PCR performed on human gingival biopsies from periodontitis sites revealed mRNA coding for CEACAM1, -5, -6, and -7. Immunohistochemistry showed that CEACAMs were not found in oral gingival epithelium, except for CEACAM5 in periodontitis. Carcinoembryonic antigen-related cellular adhesion molecules 1, 5, and 6 were present in the oral sulcular epithelium of periodontitis but not in that of healthy gingiva. In junctional epithelium, all three molecules were present in healthy gingiva, but in periodontitis only CEACAM1 and -6 were detected. Staining for CEACAM1 and -6 was also seen in the inflammatory cell infiltrate in periodontitis. No staining for CEACAM7 was found. Proinflammatory mediators, including lipopolysaccharide (LPS), tumour necrosis factor-α (TNF-α)/interleukin-1β (IL-1β), and interferon-γ (IFN-γ), increased the expression of CEACAM1 and CEACAM6 mRNAs in cultured human oral keratinocytes. CEACAM1 and CEACAM6 mRNAs were also strongly up-regulated upon stimulation with lysophosphatidic acid. In conclusion, the distribution of different CEACAMs was related to specific sites in the gingiva. This might reflect different functional roles in this tissue.