%0 Journal Article %T Epithelial Antimicrobial Peptides: Guardian of the Oral Cavity %A Mayank Hans %A Veenu Madaan Hans %J International Journal of Peptides %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/370297 %X Gingival epithelium provides first line of defence from the microorganisms present in dental plaque. It not only provides a mechanical barrier but also has an active immune function too. Gingival epithelial cells participate in innate immunity by producing a range of antimicrobial peptides to protect the host against oral pathogens. These epithelial antimicrobial peptides (EAPs) include the ¦Â-defensin family, cathelicidin (LL-37), calprotectin, and adrenomedullin. While some are constitutively expressed in gingival epithelial cells, others are induced upon exposure to microbial insults. It is likely that these EAPs have a role in determining the initiation and progression of oral diseases. EAPs are broad spectrum antimicrobials with a different but overlapping range of activity. Apart from antimicrobial activity, they participate in several other crucial roles in host tissues. Some of these, for instance, ¦Â-defensins, are chemotactic to immune cells. Others, such as calprotectin are important for wound healing and cell proliferation. Adrenomedullin, a multifunctional peptide, has its biological action in a wide range of tissues. Not only is it a potent vasodilator but also it has several endocrine effects. Knowing in detail the various bioactions of these EAPs may provide us with useful information regarding their utility as therapeutic agents. 1. Introduction Oral cavity is a diverse ecosystem where several microbes, commensal and pathogenic, interact and proliferate in the moist and warm environment. It is perhaps the only ecosystem of the human body which is dynamic, open, and close at the same time. The uniqueness of the oral cavity also lies in the presence of specialized interface which in the hard tissue (tooth) extrudes through the underlying soft tissue (gingival epithelium) [1]. The gingival epithelium constitutes oral epithelium, sulcular epithelium, and junctional epithelium. Since the tooth surface is invariably covered by a layer of microbial biofilm termed ¡°dental plaque,¡± the surrounding epithelium is continuously exposed to microorganisms and their products [2]. The role of gingival epithelium has been under the scanner because of this close interaction. Previously considered to be an innocent bystander, its active role in host microbial interaction has been elucidated with recent research [3]. Gingival epithelium works in many ways for the protection of underlying connective tissue. First, it provides a physical barrier which does not allow microbes to invade while permitting selective transaction with oral environment. Second, upon %U http://www.hindawi.com/journals/ijpep/2014/370297/