JAOB / Lion Dental Research Award ) Host Defense of Oral Mucosa and the Molecular Mechanism of Oral Mucosal Signal Tiransduction Diseases

It is speculated more that 400 bacterial species reside in the ora1 eavity and the integrity of oral mucosa is maintained in such an environment. Oral mucosal cells such as epithelial cells and fibroblasts express a wide variety of receptors and preduce many immune regulators i, e., cytokines, chemokines, proteases, and chemical mediators and actively participate in host defenses by interacting with immune cells either directly or indirectly FUrthermore, it was evident that saliva contains many immune regulatory facters. Thus, a triangle consisting of oral mucosal cells, immune cells and saliva formed by connecting with the immune regu]ator is considered important o maintaining the integrity of oral mucosa, and dysfunction (disorder) of the triangle leads to onset of oral mucosal diseases and inflammation such as oral lichen planus, pernphigus, SOgren syndrome, ora1 canceq leukoplakia, and periodontitis. We consider oral mucosal diseases to be "Dral mucosal signal transduction diseases" ancl are investigated the molecular mechanism involved in clisease onset. Tb overcome `Joral mucosal sigtial transduction diseases", we attempted to elarify the underlying molecular mechanisms and develop appropriate therapeutic strategies. This review focuses on our recent study regarding 1 ) regulation of innate immune responses by host ancl parasitic proteases in oral mucosa, 2 ) crossJtalk between oral mucosal cells and immune cells, 3 ) activation of oral mucosal cells by proteases, and 4 ) regulation of oral mucosal responses by salivary components.