An Immunohistochemical Study of the Distribution of Immunocompetent Cells, Especially Macrophages and Ia Antigen-expressing Cells of Heterogeneous Populations, in Normal Rat Molar Pulp

Abstract

The precise distribution of various immunocompetent cells in rat molar pulp was immunohistochemically examined by use of seven anti-rat monoclonal antibodies. It was demonstrated that rat molar pulp contained many OX6 (anti-Ia antigen)-positive cells and a large number of ED1 (anti-monocytes, macrophages, and dendritic cells)-positive, ED2 (anti-tissue macrophages)-positive, and/or OX35 (anti-macrophages and CD4+ lymphocytes)-positive cells. Macrophage-like cells predominated in the central portion of the pulp, while cells of dendritic appearance usually existed in the periphery of the pulp. Double-immunoperoxidase staining revealed that these cells showed some heterogeneity, but the majority could be classified as ED1+/OX6-/ED2+ cells, which may be Ia-histiocytes. Findings also suggested that true dendritic cells may be included in the ED1+/OX6+/ED2- category of cells. A small number of T lymphocytes and plasma cells were also detected. These results suggest that the normal dental pulp contains a variety of immunocompetent cells, with macrophages as the most dominating. Following the exogenous invasion of pathogenic stimuli in the pulp, these cells may participate in the defense reaction by acting as phagocytes or antigen-presenting cells, which are essential for the initiation of immune responses.

Evaluation of the responses of MHC class II molecule-expressing cells and macrophages to epoxy resin-based and 4-META-containing, methacrylate resin-based root canal sealers in rat subcutaneous tissue

“…Staining for MHC class II molecules and CD43 were present on the cell membrane, while CD68 showed a distinct granular cytoplasmic staining pattern, as described previously 8,31) . Negative control staining did not reveal any specific immunoreaction.…”

“…2f and i). The majority of these cells were identified as neutrophils 8,31) . Occasional mononuclear cells that showed CD43 immunoreactivity were also detected.…”

Cystatin C-positive Macrophages and Dendritic Cells in the Rat Incisor Pulp

“…Odontoblasts line the periphery of the pulp, to elaborate dentin matrices [8,26]. Immune competent cells, such as macrophages and dendritic cells, have also been reported to be abundant in the dental pulp [9,14,16,17]. It is thought that these cells function in immunological defense [9,17], clearance of apoptotic fragments [14] and elimination of degenerated odontoblasts from the incisal pulp [16].…”

Envolvimento de sinais coestimulatórios na periodontite apical crônica em humanos

“…Os resultados encontrados confirmam que a composição celular varia significativamente, dependendo do estágio de desenvolvimento e de progressão da lesão, das características histológicas das lesões, da presença ou ausência de sintomas clínicos e dos métodos utilizados para detecção e quantificação de células inflamatórias. Os achados mais frequentes são de que linfócitos T e plasmócitos representam a população predominante de células infiltradas (KOOP; SCHWARTING, 1989, SOL et al, 1998, COLIĆ et al, 2009 1987, STASHENKO;YU, 1989, OKIJI et al, 1992SPEIGHT, 1998, RODINI;LARA, 2001, LIAPATAS et al, 2003, COLIĆ et al, 2009). …”

“…Comparando as populações de linfócitos B e T, as periodontites apicais crônicas demonstram um acumulo de células T, visto tanto em humanos como em lesões periapicais induzidas em ratos (JONTELL; GUNRAJ; BERGENHOL, 1987, ALAVI; GULABIVALA; SPEIGHT, 1998, OKIJI et al, 1992. Este dado, aliado à presença constante de macrófagos, confirma a predominância da reação de hipersensibilidade tardia no mecanismo de formação das lesões periapicais crônicas (YU; STASHENKO, 1987 CYMERMAN et al, 1984, KONTIAINEN;RANTA;LAUTENSCHLAGER, 1986, BARKHORDAR;SOUZA, 1988, PIATTELLI et al, 1991, SOL et al, 1998YU, 1989, ALAVI;SPEIGHT, 1998, RODINI;LARA, 2001 Os mastócitos são células escassas nas lesões periapicais.…”