1. ¹Department of Otorhinolaryngology, Head and Neck Surgery, University of Luebeck, Luebeck, Germany
2. ²Clinical Research Unit, Department of Dermatology, Christian-Albrechts-University, Kiel, Germany
3. ³Department of Pathology, Christian-Albrechts-University, Kiel, Germany
4. ⁴Department of Otorhinolaryngology, Head and Neck Surgery, Krankenhaus-Holweide, Cologne, Germany

Correspondence: JE Meyer, (jens.meyer@hno.uni-luebeck.de)

⁵These authors contributed equally to this manuscript.

Received 5 October 2007; Accepted 15 January 2008; Published online 5 March 2008.

Abstract

The human tongue is particularly resistant to bacterial infections although the mouth is continuously exposed to a complex and abundant ensemble of microbes, such as the common intestinal bacterium Escherichia coli. We show that lingual epithelia produce and release, as a primary E. coli-killing compound, the S100 protein psoriasin. No significant reduction in psoriasin release could be achieved through repeated rinsing of the epithelial surface of the tongue. Psoriasin is produced in the upper layers of the lingual epithelia but is lacking in the most superficial and basal cells. It displays a gradient pattern of expression with decreasing expression from the anterior one-third to the posterior portion of the tongue. Thus, psoriasin may be the key to the resistance of the human tongue toward E. coli.