An Overview of Physical, Microbiological and Immune Barriers of Oral Mucosa

Abstract

The oral mucosa, which is the lining tissue of the oral cavity, is a gateway to the body and it offers first-line protection against potential pathogens, exogenous chemicals, airborne allergens, etc. by means of its physical and microbiological-immune barrier functions. For this reason, oral mucosa is considered as a mirror to the health of the individual as well as a guard or early warning system. It is organized in two main components: a physical barrier, which consists of stratified epithelial cells and cell–cell junctions, and a microbiological-immune barrier that keeps the internal environment in a condition of homeostasis. Different factors, including microorganism, saliva, proteins and immune components, have been considered to play a critical role in disruption of oral epithelial barrier. Altered mucosal structure and barrier functions results in oral pathologies as well as systemic diseases. About 700 kinds of microorganisms exist in the human mouth, constituting the oral microbiota, which plays a significant role on the induction, training and function of the host immune system. The immune system maintains the symbiotic relationship of the host with this microbiota. Crosstalk between the oral microbiota and immune system includes various interactions in homeostasis and disease. In this review, after reviewing briefly the physical barriers of oral mucosa, the fundamentals of oral microbiome and oral mucosal immunity in regard to their barrier properties will be addressed. Furthermore, their importance in development of new diagnostic, prophylactic and therapeutic strategies for certain diseases as well as in the application for personalized medicine will be discussed.

Protein Cargo of Salivary Small Extracellular Vesicles as Potential Functional Signature of Oral Squamous Cell Carcinoma

“…The enrichment of these proteins in the S/SEVs from patients with OSCC_LNM could be indicative of dysbiotic signatures occurring during tumor progression. Evidence accumulated in the last years indicates that alterations of the oral microbiome can have a role in inducing oral cancer progression [49][50][51][52]. Interestingly, some of these proteins (as S100 proteins and LCN2) are described as diagnostic and prognostic markers for several types of tumors, even though their role in oral cancer is controversial [48,53,54].…”

A Phenolic-rich Extract of Cocoa (Theobroma cacao L.) Beans Impairs the Pathogenic Properties of Porphyromonas gingivalis and Attenuates the Activation of Nuclear Factor Kappa B in a Monocyte Model

“…The oral mucosal epithelium is a selective protective barrier that prevents the translocation of periodontal pathogens into gingival connective tissues [ 8 , 9 ]. In a previous investigation, we showed that the cocoa extract used in the present study can improve the barrier function of an oral keratinocyte model by increasing TEER.…”

“…The oral mucosa is the first line of defense of the periodontium and acts as a barrier to protect the deeper periodontal connective tissues against bacterial invasion and toxin penetration [ 8 , 9 ]. This protective function is provided by specialized intercellular tight junction proteins that seal the paracellular space between closely opposed cells and govern the permeability of the epithelial barrier [ 8 , 9 ]. However, some periodontal pathogens such as P. gingivalis have evolved effective strategies to counteract the protective function of the epithelial barrier [ 10 , 11 ].…”

Study of Tribological Properties of Human Buccal Epithelium Cells’ Membranes Using Probe Microscopy

“…The good accessibility and non-traumatic reproduction of the collection of such cells relative to the oral mucosa, as well as the simplicity and low cost of sample preparation, makes them a convenient biological material for in vivo diagnostics of most socially signi cant diseases [4,5]. These cells are highly informative regarding to the in uence of various physical, mechanical, chemical, environmental factors and drugs on the human body [6,7]. The surfaces of the oral mucosa play a signi cant role in the sensory formation of touch, smell and taste, which is largely re ected in the psychoemotional state of a person [8].…”