Distribution of la antigen-expressing nonlymphoid cells in various stages of induced periapical lesions in rat molars

Okiji, Takashi; Kawashima, Nobuyuki; Kosaka, T; Kobayashi, Chihiro; Suda, Hiroshi

doi:10.1016/s0099-2399(06)80023-3

Cited by 35 publications

(21 citation statements)

References 16 publications

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“…In the present study, macrophage elastase first appeared in the periradicular lesion at 7 days and predominated at 14, 21, and 28 days. The most evident increase in OX6-positive cells (macrophages) in this lesion was observed at an early stage postoperatively (29). When macrophages are activated, they may participate in triggering the development in this lesion (30).…”

Section: Discussionmentioning

confidence: 76%

The Expression of Macrophage and Neutrophil Elastases in Rat Periradicular Lesions

Morimoto

Yamasaki

Nakata

et al. 2008

Journal of Endodontics

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Section: Discussionmentioning

confidence: 76%

The Expression of Macrophage and Neutrophil Elastases in Rat Periradicular Lesions

Morimoto

Yamasaki

Nakata

et al. 2008

Journal of Endodontics

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“…Four weeks of pulp exposure is regarded as the expansion term of rat periapical lesions, which stabilize thereafter (38,39). Considering that bacteria exist around the root apex and induce an inflammatory reaction in periapical tissue (40,41) and because of the existence of extraradicular biofilms, a shift to a stabilized period from a lesion expansion period may be affected.…”

Section: Discussionmentioning

confidence: 99%

Promotion of Endodontic Lesions in Rats by a Novel Extraradicular Biofilm Model Using Obturation Materials

Kuremoto

Noiri

Ishimoto

et al. 2014

Appl Environ Microbiol

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bAlthough extraradicular biofilm formation is related to refractory periapical periodontitis, the mechanism of extraradicular biofilm development, as well as its effect on periapical lesions, is unknown. Therefore, we aimed to develop an in vivo extraradicular biofilm model in rats and to identify and quantify extraradicular biofilm-forming bacteria while investigating the effect of extraradicular biofilms on periapical lesions. Periapical lesions were induced by exposing the pulpal tissue of the mandibular first molars of male Wistar rats to their oral environment. Four weeks later, gutta-percha points were excessively inserted into the mesial root canals of the right first molars (experimental sites) but not the left first molars (control sites). After 6 and 8 weeks of pulp exposure, the presence of extraradicular biofilms was confirmed histomorphologically, and biofilm-forming bacteria were identified by using classical culture methods. The biofilms were observed in the extraradicular area of the experimental sites. Similar species were detected both inside and outside the root canals. The bacterial count, quantified by real-time PCR assays, in the extraradicular area gradually increased in the experimental sites until 20 weeks after pulp exposure. After 8 weeks of pulp exposure, the periapical lesion volume that was measured by micro-computed tomography was significantly larger in the experimental sites than in the control sites (P < 0.05 by Welch's t test). These results suggest that we developed an extraradicular biofilm model in rats and that extraradicular biofilms affect developing periapical lesions. In clinical practice, we encounter patients in whom periapical periodontitis does not heal despite a root canal treatment following general dental procedures. The etiology is considered to be the result of residual bacteria in the lateral branch of the root canal, endodontic reinfection, or both. Recent studies have shown that biofilms that form outside the apical foramen, which are termed "extraradicular biofilm," are also involved in refractory periapical periodontitis (1-4). As the bacteria in biofilms are resistant to the host's immunoreaction and to antibiotics (5), dental biofilm diseases such as caries or periodontitis have been treated by mechanical removal. However, extraradicular biofilm is impossible to remove mechanically with nonsurgical endodontic treatments. As extraradicular biofilms cannot be accessed from the root canal for mechanical removal, the only treatment methods are endodontic surgery and tooth extraction.Current research is focused on developing methods to prevent or control biofilm formation (6, 7). We recently found three analogues of N-acyl homoserine lactone that participate in quorum sensing, a system of bacterial cell-to-cell communication, and inhibit Porphyromonas gingivalis biofilm formation (8). Furthermore, azithromycin, a 15-membered macrolide antibiotic, has an antibiofilm effect on P. gingivalis (9). For clinical applicability, these in vitro effects should be exami...

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“…They later reported age-related changes in the macrophage-associated antigen expressing cells during rat molar development, suggesting that the changes with age may reflect the immunological defense potential of the dental pulp (Okiji et al 1996). In addition, previous reports showed increased accumulation of class II MHC-positive cells including macrophages and dendritic cells in caries and cavity preparations, pulp exposure, and tooth replantation of rat molars (Kamal et al 1997;Ohshima et al 1995;Okiji et al 1994;Rungvechvuttivittaya et al1998) and in caries lesions of human teeth (Yoshiba et al 1996). In the present study, the lack of Mac-1-positive cells, disappearance of Mac-2-positive cells, and scattered distribution of MOMA-2-positive cells may reflect the low intensity of the pulpal defense reaction at the early stages of mouse molar development before eruption and crucial exposure to antigenic stimuli.…”

Section: Discussionmentioning

confidence: 96%

“…Dendritic cells show no or little activity of acid phosphatase (ACP), whereas macrophages have phagocytic capability and exhibit ACP activity that is dependent on the phagocytic capability (Steinman et al 1986). Class II MHC antigen-expressing cells have been identified in the dental pulp of humans and rats by immunohistochemistry using HLA-DR and OX-6 antibodies (Jontell et al 1987(Jontell et al , 1988(Jontell et al , 1991(Jontell et al , 1994Ohshima et al 1994Ohshima et al , 1995Ohshima et al , 1999Okiji et al 1994Okiji et al , 1996Okiji et al , 1997Yoshiba et al 1996). Based on the criteria of the expression of class II MHC antigens and the activity of ACP, previous studies have indicated that, whereas macrophages are present in the central region of the dental pulp, dendritic cells are located in and around the odontoblastic layer.…”

Section: Introductionmentioning

confidence: 99%

Appearance and distribution of dendritic cells and macrophages in dental pulp during early postnatal morphogenesis of mouse mandibular first molars

Tsuruga

Sakakura

Yajima

et al. 1999

Histochemistry and Cell Biology

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Dendritic cells and macrophages were examined in dental pulp during the postnatal development of mouse mandibular first molars, by immuno- and enzyme histochemistry. F4/80 antibody against dendritic cells and macrophages demonstrated labeled cells predominantly in and around the odontoblastic layer during tooth development from postnatal day 0 (PN0) to PN5. Labeling with Mac-1, Mac-2, and MOMA-2 antibodies against macrophages showed varied distribution patterns. Mac-1-positive cells were not detected in the dental pulp. Mac-2-positive cells appeared in the dental pulp at PN0, but not in or around the odontoblastic layer, and disappeared by PN3. A few MOMA-2-positive cells were detected in the dental pulp during the period examined. The F4/80-positive cells in and around the odontoblastic layer did not exhibit acid phosphatase or non-specific esterase activities. In addition, the F4/80-positive cells showed continued expression of Fcgamma receptor, but not class II major histocompatibility complex (MHC). Other antibodies against dendritic cells (NLDC-145, MIDC-8, and 33D1) did not label the F4/80-positive cells. We concluded that the F4/80-positive and class II MHC-negative cells in and around the odontoblastic layer may be immature dendritic cells in the early stages before eruption, weaning, and crucial exposure to antigenic stimuli. They may not only act primarily as immunosurveillance cells, but also play a role in a regulatory function and differentiation of odontoblasts.

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Distribution of la antigen-expressing nonlymphoid cells in various stages of induced periapical lesions in rat molars

Cited by 35 publications

References 16 publications

The Expression of Macrophage and Neutrophil Elastases in Rat Periradicular Lesions

The Expression of Macrophage and Neutrophil Elastases in Rat Periradicular Lesions

Promotion of Endodontic Lesions in Rats by a Novel Extraradicular Biofilm Model Using Obturation Materials

Appearance and distribution of dendritic cells and macrophages in dental pulp during early postnatal morphogenesis of mouse mandibular first molars

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