Differential immune responses of 3D gingival and periodontal connective tissue equivalents to microbial colonization

Abstract

Gingival and periodontal ligament fibroblasts are functionally distinct cell types within the dento-gingival unit that participate in host immune response. Their microenvironment influences the behavior and immune response to microbial challenge. We developed three-dimensional gingival and periodontal connective tissue equivalents (CTEs) using human fibrin-based matrix. The CTEs were characterized, and the heterogeneity in their innate immune response was investigated. The CTEs demonstrated no to minimal response to planktonic Streptococcus mitis and Streptococcus oralis, while their biofilms elicited a moderate increase in IL-6 and IL-8 production. In contrast, Fusobacterium nucleatum provoked a substantial increase in IL-6 and IL-8 production. Interestingly, the gingival CTEs secreted significantly higher IL-6, while periodontal counterparts produced higher IL-8. In conclusion, the gingival and periodontal CTEs exhibited differential responses to various bacterial challenges. This gives insights into the contribution of tissue topography and fibroblast heterogeneity in rendering protective and specific immune responses toward early biofilm colonizers.

Modeling Crevicular Fluid Flow and Host‐Oral Microbiome Interactions in a Gingival Crevice‐on‐Chip

“…In the recent past, there has been a growing interest in the development and application of in vitro 3D organotypic cultures of reconstructed gingival epithelium, [23,[49][50][51] connective tissue [52,53] and full-thickness [18,[54][55][56][57] equivalents to recapitulate native tissue microenvironment and to understand periodontal host-microbiome interactions. Previous studies have also demonstrated the development of in vitro organotypic mod-els related to the gingival crevice that include dento-gingival junction, sulcular epithelium, and junctional epithelium.…”

“…Previous studies have also demonstrated the development of in vitro organotypic mod-els related to the gingival crevice that include dento-gingival junction, sulcular epithelium, and junctional epithelium. [55,[58][59][60] These models have provided insights into the role of subgingival biofilms, [23,49,51,56,57] Porphyromonas gingivalis [18,50] and F. nucleatum [53][54][55] in host-microbiome interactions, epithelial barrier, and periodontal pathogenesis. In these 3D organotypic epithelial models, the microbes are introduced on the apical surface of the tissue equivalents that are cultured under static conditions, wherein the role of GCF is not considered.…”

“…Culture of Gingival CTEs within the Microfluidic Device: Donor-derived primary gingival fibroblasts (passage 5-7) isolated from gingival tissues attached to healthy, non-carious impacted third molars were cultured as previously described. [53] 5 × 10 3 gingival fibroblasts were encapsulated within 10 μL of human fibrin-based 3D matrix as previously described [53] and seeded inside the culture chamber of the microfluidic device. Unidirectional flow of culture media through the matrix of the gingival CTE was controlled by adjusting the media volumes (hydrostatic pressure difference) between the media reservoirs supplying the tissue fluid and crevicular channels.…”

Fluid flow-induced modulation of viability and osteodifferentiation of periodontal ligament stem cell spheroids-on-chip

“…The PDLSCs isolated under ACF conditions were expanded under the same media conditions without amphotericin-B, and characterized for the expression of surface markers using flow cytometry as described previously. 52…”

Microphysiological Modeling of Gingival Tissues and Host‐Material Interactions Using Gingiva‐on‐Chip

“…[ 1,5 ] Existing standards are commonly based on assays using monolayer cultures of a single cell type. In recent years, there has been a significant impetus toward the development and application of in vitro three‐dimensional (3D) organotypic models that emulate the complex microenvironment of the gingiva and oral mucosa such as reconstructed epithelium, [ 6–8 ] connective tissue [ 9 ] and full‐thickness gingival [ 10–15 ] equivalents. These 3D models offer a physiological alternative to understanding the host‐material and host‐microbial interactions.…”