Histological and immunological characteristics of the junctional epithelium

Abstract

SummaryThe continuity of epithelial tissue is collapsed by tooth eruption. The junctional epithelium (JE) is attached to the tooth surface by hemidesmosomes, which constitutes the front-line defense against periodontal bacterial infection. JE constitutively expresses intercellular adhesion molecule-1 (ICAM-1), and neutrophils and lymphocytes penetrate into JE via interaction between ICAM-1 and LFA-1 expressed on the surface of these migrating cells. JE also expresses cytokines and chemokines. These functions of JE are maintained even in germ-free condition. Therefore, the constitutive expression of adhesion molecules, cytokines, and chemokines might be used not only for anti-pathogenic defense but also for maintaining the physiological homeostasis of JE. In this review, we have mainly focused on the structural and functional features of JE, and discussed the function of intraepithelial lymphocytes in JE as a front-line anti-microbial defense barrier and regulator of JE hemostasis.

A Novel Proposal of Salivary Lymphocyte Detection and Phenotyping in Patients Affected by Sjogren’s Syndrome

“…Whole saliva cell immunophenotyping revealed that patients with CP had a higher frequency of total leukocytes, B-cells, NK cells, and CD4(+) T-cells than individuals without oral pathologies [14]. The lymphocytes in whole saliva are probably obtained from junctional epithelium [32], gingival crevicular fluid [33], and oral mucosa [34], which contain lymphocytes as components of host defense. However, we did not find in the available literature any studies according to lymphocytes in pure parotid saliva in healthy and periodontal patients.…”

Single-cell RNA sequencing identifies heterogeneous cell subtypes within gingival tissue

“…We found junctional epithelial and basal are both the beginning of the trajectory. This finding could be explained by the fact that junctional epithelial has the basement membrane-like structures with low differentiation and high regeneration ability 42,43 . Then, the trajectory experiences the spinous and end at the GRN3.…”

Gingival Response to Dental Implant: Comparison Study on the Effects of New Nanopored Laser-Treated vs. Traditional Healing Abutments

“…In periodontal inflammation, the neutrophils present in the gingival tissue are directed towards the bacteria of the dental plaque following specific chemotactic factors produced by the junctional epithelium (JE), the Intercellular Adhesion Molecule 1 (ICAM-1), necessary to help neutrophils in orienting themselves in molecular traffic [ 11 ]. Keratinocytes of healthy epithelium do not express ICAM-1, while keratinocyte ICAM-1 expression is detected in epithelial diseases: it localized in the inflammatory infiltration site of the epithelium and it is regulated by pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) [ 12 , 13 ]. Therefore, regulation of ICAM-1 expression and differences in ICAM-1 levels in JE might depend not only on bacteria-derived lipopolysaccharides, but also on local inflammatory factors [ 12 ].…”

“…Keratinocytes of healthy epithelium do not express ICAM-1, while keratinocyte ICAM-1 expression is detected in epithelial diseases: it localized in the inflammatory infiltration site of the epithelium and it is regulated by pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) [ 12 , 13 ]. Therefore, regulation of ICAM-1 expression and differences in ICAM-1 levels in JE might depend not only on bacteria-derived lipopolysaccharides, but also on local inflammatory factors [ 12 ]. TNF-α is one of the main culprits in the progression of the gingival inflammation and bone resorption, stimulating both the osteoclast activity and the release of Matrix Metalloproteinases (MMPs), which, in turn, catalyze the degradation of extracellular matrix, connective tissue and alveolar bone [ 14 ].…”