The Role of Dendritic Cells during Physiological and Pathological Dentinogenesis.

Angela Quispe-Salcedo,Hayato Ohshima

doi:10.3390/jcm10153348

Angela Quispe-Salcedo, Hayato Ohshima

Open Access

https://doi.org/10.3390/jcm10153348

Copy DOI

Abstract

The dental pulp is a soft connective tissue of ectomesenchymal origin that harbors distinct cell populations, capable of interacting with each other to maintain the vitality of the tooth. After tooth injuries, a sequence of complex biological events takes place in the pulpal tissue to restore its homeostasis. The pulpal response begins with establishing an inflammatory reaction that leads to the formation of a matrix of reactionary or reparative dentin, according to the nature of the exogenous stimuli. Using several in vivo designs, antigen-presenting cells, including macrophages and dendritic cells (DCs), are identified in the pulpal tissue before tertiary dentin deposition under the afflicted area. However, the precise nature of this phenomenon and its relationship to inherent pulp cells are not yet clarified. This literature review aims to discuss the role of pulpal DCs and their relationship to progenitor/stem cells, odontoblasts or odontoblast-like cells, and other immunocompetent cells during physiological and pathological dentinogenesis. The concept of “dentin-pulp immunology” is proposed for understanding the crosstalk among these cell types after tooth injuries, and the possibility of immune-based therapies is introduced to accelerate pulpal healing after exogenous stimuli.

Highlights

The dental pulp is a specialized soft connective tissue of ectomesenchymal origin harboring distinct cell populations with specific functions involved in teeth production and maintenance [1,2,3]
Kannari et al reported that in the dental pulp of human deciduous teeth under physiological root resorption, major histocompatibility complex (MHC)+ class II cells were seen in the same location as in previous reports, extending their processes into the dentinal tubules [41]
The findings of this study suggested that bacterial infection and subsequent abscess formation impaired dendritic cells (DCs) recruitment, which may have contributed to the delay in the pulpal repair/regeneration process [46]

Summary

Introduction

The dental pulp is a specialized soft connective tissue of ectomesenchymal origin harboring distinct cell populations with specific functions involved in teeth production and maintenance [1,2,3]. The tertiary dentin matrix secreted by surviving odontoblasts in response to a mild stimulus is defined as reactionary dentin; whereas reparative dentin is defined as the matrix deposited beneath the afflicted area by newly differentiated odontoblast-like cells after the death of the original odontoblasts due to severe injuries [7,23,24,25,26,27,28,29,30,31,32,33] The latter implies a more complex process involving important biological mechanisms, such as apoptosis, cell proliferation, and cell differentiation, which remain to be elucidated at cellular and gene levels [34,35,36,37,38]. This literature review discusses the possible role of dental pulp DCs and their relationship to odontoblasts, DPSCs, and other resident cells involved during physiological and pathological dentinogenesis

Key Functions of DCs

Relationship between DCs and Odontoblasts during Physiological Dentinogenesis

Relationship

Relationship between DCs and Odontoblasts or Newly Differentiated

Responses of DCs to Bacterial Infection in the Dental Pulp

Conclusions