Tissue-Specific Immunity at the Oral Mucosal Barrier Niki M. Moutsopoulos, Joanne E. Konkel  Trends in Immunology  Volume 39, Issue 4, Pages 276-287 (April 2018) DOI: 10.1016/j.it.2017.08.005 Copyright © 2017 Terms and Conditions

Figure 1 The Oral and Gingival Barrier. The oral mucosa is lined by stratified squamous epithelia of varying thickness and level of keratinization. Most the oral mucosa is covered by a lining of non-keratinized epithelium (the floor of mouth being particularly thin and vascular). The areas related to mastication (hard palate, outer surface of gingiva) are partially keratinized epithelia, and the tongue is covered with a specialized epithelium that incorporates the taste buds. The gingival crevice is a particularly open and vulnerable site. It is lined by the sulcular epithelium that is non-keratinized and becomes progressively thinner, transitioning to the junctional epithelium which connects to the tooth surface and is constantly exposed to the microbial biofilm and experiences trauma, leading to constant immune activation. Trends in Immunology 2018 39, 276-287DOI: (10.1016/j.it.2017.08.005) Copyright © 2017 Terms and Conditions

Figure 2 The Immunological Network of the Gingiva. The gingiva is home to a rich immunological network. Neutrophils continuously transmigrate through the junctional epithelium. Resident lymphocytes are predominately T cells, with some B cells and innate lymphoid cells (ILCs). Diverse mononuclear phagocytes are also present at this site. Abbreviations: APC, antigen-presenting cell; DC, dendritic cell; ILC, innate immune cell; SSC, side scatter. Trends in Immunology 2018 39, 276-287DOI: (10.1016/j.it.2017.08.005) Copyright © 2017 Terms and Conditions

Figure 3 Tissue-Specific Cues Tailoring Immunity at the Oral Barrier. Diverse microbial commensal communities and ongoing damage have been established to educate immune function at the gingiva, while dietary elements and airborne allergens/particles are speculated to play a role in the training of local immunity. Trends in Immunology 2018 39, 276-287DOI: (10.1016/j.it.2017.08.005) Copyright © 2017 Terms and Conditions