Immunohistochemical Localization of HLA-DR-positive Cells in Unerupted and Erupted Normal and Carious Human Teeth

Yoshiba, Nagako; Yoshiba, Kunihiko; Nakamura, Hiroaki; Iwaku, Masaaki; Ozawa, Hiroki

doi:10.1177/00220345960750081001

Cited by 61 publications

(52 citation statements)

References 18 publications

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“…Signals provided by T-lymphocytes most likely are prerequisite for the activation of other antigenspecific effector cells such as B-lymphocytes. Recently, distribution of HLA-DR-and factor Xlllaexpressing pulpal DCs in human carious teeth has been reported Yoshiba et al, 1996). In teeth with dentinal caries of various depths but without carious pulp exposures, there was a marked localized accumulation of these DCs at the pulpal region immediately subjacent to the pulpal end of the carious dentinal tubules.…”

Section: Dense Sensory Innervationmentioning

confidence: 99%

Immune Defense Mechanisms of the Dental Pulp

Jontell

Okiji

Dahlgren

et al. 1998

Critical Reviews in Oral Biology & Medicine

204

169

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Defense reactions of the dentin/pulp complex involve a variety of biological systems, in which the immune system plays a pivotal role. The knowledge of the organization and function of pulpal immunocompetent cells has been sparse, but in recent years a significant body of information of immune mechanisms in general has provided a footing for substantial new knowledge of the immune mechanisms of the dental pulp. The identification of pulpal dendritic cells (DCs) has generated research activities which have led to a concept of how an antigenic challenge may evoke a pulpal inflammatory response. Although DCs are not able to identify foreign antigens specifically, they provide necessary signals to activate T-lymphocytes which in turn will orchestrate other immunocompetent cells to mount the local immune defense of the dental pulp. The purpose of this review is to accent the organization and function of pulpal DCs and other tissue and cellular components and to provide a basis for how they may interact to instigate pulpal defense mechanisms.

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Section: Dense Sensory Innervationmentioning

confidence: 99%

Immune Defense Mechanisms of the Dental Pulp

Jontell

Okiji

Dahlgren

et al. 1998

Critical Reviews in Oral Biology & Medicine

204

169

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“…Lipoteichoic acid and peptidoglycan are known to induce IL-12 by dendritic cells or monocytes and IL-12 promotes induction of Th1 responses and IFN-␥ production (4,26). A striking aggregation of pulpal dendritic cells is present in the dental pulps under shallow caries, suggesting that this highly efficient antigen-presenting cell may be a source of IL-12 in shallow lesions (27,32). Bacterial antigens from S. mutans and Streptococcus sanguis have been ultrastructurally localized in the dentinal tubules and pulpal tissues (2).…”

Section: Vol 68 2000 S Mutans and Pulpal Pathogenesis 6787mentioning

confidence: 99%

Cytokine Induction byStreptococcus mutansand Pulpal Pathogenesis

2000

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Chronic pulpal inflammation under caries appears to be elicited by bacterial antigens that diffuse into the pulp through dentinal tubules. This prompted the hypothesis that cytokines elicited by antigens from Streptococcus mutans, which frequently dominates shallow lesions, could play a major role in eliciting the initial T-cell response in the pulp. To test this, we examined the ability of S. mutans to stimulate T cells and elicit cytokines and used Lactobacillus casei, which often predominates in deep carious lesions where B cells and plasma cells predominate, as a control. In addition, the presence of cytokines in the pulp was analyzed at the mRNA level. S. mutans elicited potent gamma interferon (IFN-␥) responses in peripheral blood mononuclear cell cultures and reduced the CD4/CD8 ratio by promoting CD8 ؉ T cells. Multiple inflammatory cytokine mRNAs (IFN-␥, interleukin 4 [IL-4], and IL-10) were detected in human dental pulp. A higher prevalence of IFN-␥ (67%) than IL-4 (19%) or IL-10 (29%) was obtained in shallow caries, suggesting a type 1 cytokine mechanism in early pulpitis where S. mutans predominates. In contrast, in deep caries no differences in cytokine frequency were observed. Furthermore, the presence of IFN-␥ in the pulp correlated with the presence of S. mutans. The extraordinary induction of type 1 cytokines and the preferential activation of CD8 ؉ T cells by S. mutans offers an explanation for the etiology of the CD8 ؉ T-cell-dominant lesion in early pulpitis and suggests that S. mutans may have a major impact on the initial lesion and pulpal pathology.Although the dental pulp is equipped with cells of the immune system (16), the immune response in the pulp to caries pathogens is poorly understood. A chronic pulpal inflammation under caries is likely elicited by bacterial antigens that diffuse into the pulp through dentinal tubules (2,3,14). Immunohistological studies of dental pulps under shallow caries have revealed a lesion that is restricted almost exclusively to T cells, with CD8 ϩ T cells predominating (9, 14). As the carious lesion enlarges and invades the inflamed dental pulp, CD8 ϩ T cells continue to dominate but CD4 ϩ T cells, B cells, and plasma cells appear in substantial numbers (9,14). We are interested in understanding why the immune cell types shift during caries progression. We reasoned that antigens associated with the caries pathogens may preferentially elicit different immune cell types during caries invasion. The dominant organisms in the lesions, which likely elicit host responses, shift from Streptococcus mutans in shallow caries to Lactobacillus casei in deep carious lesions.A type 1 cytokine response is defined as promoting cellmediated response, with gamma interferon (IFN-␥) as the prototypic cytokine and a clear association with interleukin 2 (IL-2), tumor necrosis factor beta, and IL-12. A type 2 response is characterized as promoting one or more B-cell activities, with IL-4 as the prototypic cytokine and an association with IL-5, IL-6, IL-10, and IL-13 (18). This ...

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“…This includes the secretion of proinflammatory chemokines and cytokines that recruit and activate blood borne inflammatory cells (10,11). In the dental pulp, when dentin is being destroyed by caries, immature dendritic cells (iDCss) accumulate into the odontoblast layer close to the lesion in strategic location to sample foreign Ags (3,12). Factors favoring this accumulation are unknown, but chemokines may be involved (13).…”

mentioning

confidence: 99%

Lipoteichoic Acid Increases TLR and Functional Chemokine Expression while Reducing Dentin Formation in In Vitro Differentiated Human Odontoblasts

Durand

Flacher

Roméas

et al. 2006

The Journal of Immunology

159

172

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Gram-positive bacteria entering the dentinal tissue during the carious process are suspected to influence the immune response in human dental pulp. Odontoblasts situated at the pulp/dentin interface are the first cells encountered by these bacteria and therefore could play a crucial role in this response. In the present study, we found that in vitro-differentiated odontoblasts constitutively expressed the pattern recognition receptor TLR1–6 and 9 genes but not TLR7, 8, and 10. Furthermore, lipoteichoic acid (LTA), a wall component of Gram-positive bacteria, triggered the activation of the odontoblasts. LTA up-regulated the expression of its own receptor TLR2, as well as the production of several chemokines. In particular, an increased amount of CCL2 and CXCL10 was detected in supernatants from LTA-stimulated odontoblasts, and those supernatants augmented the migration of immature dendritic cells in vitro compared with controls. Clinical relevance of these observations came from immunohistochemical analysis showing that CCL2 was expressed in vivo by odontoblasts and blood vessels present under active carious lesions but not in healthy dental pulps. In contrast with this inflammatory response, gene expression of major dentin matrix components (type I collagen, dentin sialophosphoprotein) and TGF-β1 was sharply down-regulated in odontoblasts by LTA. Taken together, these data suggest that odontoblasts activated through TLR2 by Gram-positive bacteria LTA are able to initiate an innate immune response by secreting chemokines that recruit immature dendritic cells while down-regulating their specialized functions of dentin matrix synthesis and mineralization.

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Immunohistochemical Localization of HLA-DR-positive Cells in Unerupted and Erupted Normal and Carious Human Teeth

Cited by 61 publications

References 18 publications

Immune Defense Mechanisms of the Dental Pulp

Immune Defense Mechanisms of the Dental Pulp

Cytokine Induction byStreptococcus mutansand Pulpal Pathogenesis

Lipoteichoic Acid Increases TLR and Functional Chemokine Expression while Reducing Dentin Formation in In Vitro Differentiated Human Odontoblasts

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