Jun Sato

Expression and localization of the cysteinyl leukotriene 1 receptor in human nasal mucosa

Background The cysteinyl leukotrienes (CysLT) are lipid mediators that have been implicated in the pathogenesis of allergic diseases. Pharmacological studies using CysLTs indicate that two classes of receptors, named CysLT1 and CysLT2 receptor, exist. The former is sensitive to the CysLT1 antagonist currently used to treat asthma and allergic rhinitis. Recently, the cDNA for human CysLT1 and CysLT2 receptor have been cloned, making it now possible to study the gene expression of CysLTs receptors.

Topical CTLA4–Ig Suppresses Ongoing Mucosal Immune Response in Presensitized Murine Model of Allergic Rhinitis

Allergic rhinitis is thought to be mediated by CD4+ T cells producing Th2–associated cytokines. Optimal Ag–specific T–cell activation requires the engagement of T–cell receptor with antigen (Ag) in the context of MHC, and the engagement of appropriate costimulatory molecules. One of the most well–characterized costimulatory pathways is the interaction of B7/CD28–CTLA4 molecules. Recent studies have suggested that the costimulatory pathway may influence the development of Th2 immune responses. The objective of this study was the examination of the role of B7/CD28–CTLA4 costimulatory pathway in the pathogenesis of ovalbumin (OVA)–induced immune response in presensitized murine model of allergic rhinitis. Systemically presensitized BALB/c mice significantly developed Ag–induced early phase nasal symptoms, nasal hyperresponsiveness to histamine, nasal eosinophilia, serum levels of OVA– specific IgE and Th2–associated cytokines following repeated topical Ag challenges. Topical administration of CTLA4–Ig during nasal challenges inhibited Ag–induced nasal symptoms and histamine hyperresponsiveness. We also found a significant reduction in nasal lavage eosinophilia and serum levels of OVA–specific IgE. Furthermore, CTLA4–Ig treatment significantly decreased interleukin (IL)–4 content in nasal tissue, while there was no significant change in IL–5 or IFN–γ levels. These results suggest that B7/CD28–CTLA4 costimulatory pathway mediates the development of ongoing Th2 immune responses and plays a major role in regulating allergic disease, such as allergic rhinitis.

Effect of glucocorticosteroids on tumour necrosis factor‐α‐induced intercellular adhesion molecule‐1 expression in cultured primary human nasal epithelial cells

Objective In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule‐1 (ICAM‐1) expression, we examined ICAM‐1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels.

Tumor necrosis factor increases MUC1 mRNA in cultured human nasal epithelial cells.

Objective--Mucins are high molecular weight glycoproteins which are normally expressed on the surface of a variety of epithelia. It is possible that shedding of such molecules from the epithelium could play a role in preventing bacterial colonization at the mucosal surface. Immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of human inferior turbinates have shown the existence of MUC1 mucin in nasal mucosa. However, the regulatory mechanisms of MUC1 mucin are poorly understood. In order to clarify the modulation of mucin gene expression, we developed a real-time semi-quantitative RT-PCR based on TaqMan fluorescence methodology to quantify MUC1 mRNA in primary cultured human nasal epithelial cells (HNECs).Material and Methods--HNECs were stimulated with recombinant human tumor necrosis factor (TNF)-α (20 pg/ml to 20 ng/ml) for specified time periods (0, 12, 24 and 48 h) and MUC1 mRNA was determined by means of semi-quantitative RT-PCR.Results--Significant increases in MUC1 gene expression in HNECs were initially detected at 12 h, peaking at 24 h after stimulation. TNF-mediated MUC1 mRNA expression at 24 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor.Conclusions--TNF-mediated MUC1 gene expression may contribute to the pathogenesis of human inflammatory upper airway disorders. Also, our mucin mRNA real-time PCR provides a quantitative method for investigating the regulation of mucin gene expression in both healthy and diseased samples.

Expression and Localization of Steroid Receptors in Human Nasal Mucosa

Objective—To investigate the expression of glucocorticoid receptor (GR), oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) in nasal mucosa. Material and Methods—Human turbinates were obtained after turbinectomy from seven patients. The expression and localization of steroid receptors were examined using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Results—Using RT-PCR, GR and ERα mRNA were detected in all cases. In contrast, ERβ, PR and AR mRNA were found in five, four and six cases, respectively. Using immunohistochemistry, antibodies to GR showed the presence of GR within all cells of nasal mucosa, with the highest quantities of GR being localized in epithelial cells, submucosal glands and inflammatory leukocytes. Immunohistochemical analysis of sex steroid receptor revealed that anti-ERα antibody labelled mainly mast cells and anti-ERβ antibody labelled submucosal glands, and that no PR or AR expression was detected in any of the samples tested. Conclusions—The role of ER in mast cells and submucosal glands has not been well clarified. However, precise knowledge of the identity and distribution of sex steroid receptor should be of considerable interest in understanding the role of sex hormones in upper airway diseases such as allergic and non-allergic rhinitis.

Syphilitic cervical lymphadenopathy

Syphilis is well known as a great mimic, however it is not recognized as a cause of cervical lymphadenopathy. We report a case of a 21-year-old man who presented with marked unilateral cervical lymphadenopathy. He had no evidence of oropharyngeal chancres, skin or genital lesions. Computed tomography (CT) and magnetic resonance (MR) images showed multiple cervical lymphadenopathy, and serologic tests for syphilis were positive. Syphilis should still be a factor for consideration in the differential diagnosis of cervical lymphadenopathy.

Establishment of animal model of antigen-specific T lymphocyte recruitment into nasal mucosa.

DO11.10 transgenic mice, expressing an ovalbumin (OVA)‐specific αβ T‐cell receptor (TCR), have been used as a model of various immune diseases associated with T lymphocytes. Some studies of immunoresponse in lung have involved adoptive transfer of DO11.10 mice. As of yet, however, there have been no studies of the adoptive transfer model in the upper airway. The purpose of this study was to establish an animal model to clarify the recruitment mechanism and the roles of Th2 cells in allergic rhinitis. In accordance with the adoptive transfer system, we generated Th0, Th1 and Th2 cells from DO11.10 mice and transferred them into wild type BALB/c mice. Following nasal OVA challenge to DO11.10 mice or to the BALB/c mice into which antigen‐specific Th2 cells had been transferred, the number of local antigen‐specific TCR‐positive cells accompanying the local eosinophilia had significantly increased. However, nasal OVA challenge to BALB/c mice into which antigen‐specific Th0 or Th1 cells were transferred failed to increase the number of local OVA‐specific TCR positive cells. These observations suggest that an antigen‐specific homing mechanism of Th2 cells may exist in nasal mucosa. Analysis of this model will assist in the development of new therapeutic strategy, which targets Th2 cells in allergic rhinitis.

Parasympathetic schwannoma of the submandibular gland.

Schwannomas of the submandibular gland have only been documented sporadically throughout the medical literature. We describe a case of schwannoma of the submandibular gland originating from the submandibular branch of the lingual nerve, which carries the preganglionic parasympathetic nerve fibers. The clinical aspect of this tumor is discussed, followed by a brief literature review.

Suppressive effects of CTLA4-Ig on nasal allergic reactions in presensitized murine model.

Ag-specific T cell activation requires the engagement of T cell receptor (TCR) with antigen in the context of MHC, and the engagement of appropriate costimulatory molecules. It is well established that B7/CD28-CTLA4 costimulatory pathway plays an important role in the induction of T helper (Th) cells in T-cell dependent immune reactions. In this study, we evaluated the effects of blocking the costimulatory pathway by systemic administration of CTLA4-Ig during repeated nasal antigen challenges in systemically presensitized mouse. The antigen-induced early phase nasal symptoms, nasal hyperresponsiveness to histamine and nasal eosinophilia were significantly suppressed by CTLA4-Ig treatment. Elevation of serum level of antigen-specific IgE, but not IgG1 or IgG2a was inhibited by the treatment. In relation to cytokine levels in the tissue extracts of the nasal mucosa, an up-regulation of IL-4 was significantly inhibited, however, the levels of IL-5 and IFN-gamma were not affected by the treatment. These results suggest that B7/CD28-CTLA4 costimulatory pathway plays an important role in on-going Th2-related allergic reactions in the nose.

Effects of anti-VLA-4 Monoclonal Antibody Treatment in Murine Model of Allergic Rhinitis

In order to study the role of VLA-4 in allergic rhinitis, the effects of anti-mouse VLA-4 monoclonal antibody (mAb) were evaluated in a murine model. BALB/c mice were sensitized first by i.p. injections (general sensitization) and then by daily nasal dripping of antigen (local sensitization) before performing a nasal antigen challenge. The mAb was applied either before the antigen challenge (BC group), before the local sensitization (BL group) or before the general sensitization (BS group). The effects were evaluated in terms of antigen-induced early-phase nasal symptoms (sneezing), late-phase nasal eosinophilia and the serum level of antigen-specific IgE. Antigen-induced nasal eosinophilia was significantly (p = 0.009) reduced in the BL group but not in the BC group (number of eosinophils = 114 +/- 15.1, 244 +/- 52.8 and 347 +/- 50.5 in the BL, BC and control groups, respectively). The serum level of the specific IgE was also significantly (p = 0.038) reduced in the BL group but not in the BC group (optical density = 1.18 +/- 0.07, 1.28 +/- 0.13 and 1.58 +/- 0.14 in the BL, BC and control groups, respectively). The suppressive effect on sneezing was not significant in either the BL or BC groups. In the BS group, suppressive effects on antigen-induced nasal responses and the specific IgE level were not statistically significant. These findings suggest that VLA-4 plays an important role in the topical booster or priming effects during repeated nasal antigen exposures in pre-sensitized animals.In order to study the role of VLA-4 in allergic rhinitis, the effects of anti-mouse VLA-4 monoclonal antibody (mAb) were evaluated in a murine model. BALB/c mice were sensitized first by i.p. injections (general sensitization) and then by daily nasal dripping of antigen (local sensitization) before performing a nasal antigen challenge. The mAb was applied either before the antigen challenge (BC group), before the local sensitization (BL group) or before the general sensitization (BS group). The effects were evaluated in terms of antigen-induced early-phase nasal symptoms (sneezing), late-phase nasal eosinophilia and the serum level of antigen-specific IgE. Antigen-induced nasal eosinophilia was significantly (p