Products from human mast cell line cells enhance the production of interferon-gamma by CD8+ and CD4+ T cells

Tryptase and TIM-1 double-positive mast cells in different stages of human chronic periodontitis

BACKGROUND/PURPOSE

Mast cells (MCs) play a critical role in the pathogenesis of allergic reactions and inflammatory conditions through the release of inflammatory mediators. T cell immunoglobulin mucin domain (TIM-1) has been reported to express in MCs. The aim of the present study was to examine the expression and analyze the quantification of TIM-1 on tryptase-positive MCs in different stages of human chronic periodontitis using double-immunofluorescence staining.

MATERIALS AND METHODS

Individuals who participated in this study were divided into three groups: healthy control gingivae (n = 27), chronic slight periodontitis (n = 34), and chronic severe periodontitis (n = 31). Their gingival specimens were taken and fixed in 10% buffered formalin, stained with hematoxylin and eosin (HE) for histopathology, and stained with double-immunofluorescence (DIF) for identification of tryptase-TIM-1 double-positive MCs in gingival tissues.

RESULTS

Compared with healthy controls, the densities (cells/mm²) of tryptase-TIM-1 double-positive MCs were significantly increased in both the chronic slight periodontitis (P < 0.05) and severe periodontitis groups (P < 0.01). However, compared with the chronic slight periodontitis group, both the score of gingival tissue inflammation and the density of tryptase-TIM-1 double-positive MCs in gingival tissue were significantly increased in the severe periodontitis groups (P < 0.05). Conclusion: By incorporating HE with double-immunofluorescence staining in human chronic periodontitis, the significantly increased number of tryptase-TIM-1 double-positive MCs had the similar tendency as the severity of periodontitis inflammation. Based on our results, we suggest that tryptase-TIM-1 double-positive MCs may play an important role in human chronic periodontitis.

Poor outcomes of chronic active Epstein-Barr virus infection and hemophagocytic lymphohistiocytosis in non-Japanese adult patients

Chronic active Epstein-Barr virus infection manifests as a combination of persistent infectious mononucleosis-like symptoms and high viral load in apparently immunocompetent patients. It is closely related to Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis. These 2 abnormal Epstein-Barr virus-associated diseases are seldom reported in individuals other than Japanese children and adolescents. We report a series of 2 adult non-Japanese patients with fatal chronic active Epstein-Barr virus and 1 adult non-Japanese patient with Epstein-Barr virus hemophagocytic lymphohistiocytosis and discuss its pathogenesis and treatment options.

Phenotypic changes in colonocytes following acute stress or activation of mast cells in mice: implications for delayed epithelial barrier dysfunction

BACKGROUND AND AIMS

Stressful life events are known to modulate the development or relapse of disease in both inflammatory bowel disease and irritable bowel disease patients but underlying mechanisms remain unclear. Stress is known to effect mast cells, interferon gamma (IFN-gamma), and myosin light chain phosphorylation to trigger colonic epithelial barrier dysfunction. The aim of this study was to investigate whether acute stress induced or chemical mast cell activation impaired expression and function of epithelial tight junctions, and altered colonocyte differentiation in mice.

METHODS

Colonic paracellular permeability was assessed as the in vivo lumen to blood ratio of 51Cr-EDTA in different groups of mice (controls, stressed, mast cell degranulator BrX-537A treated), pretreated or not with the mast cell stabiliser doxantrazole. Involvement of mast cells and IFN-gamma was evaluated in wild-type and IFN-gamma deficient mice. Tight junction alteration was assessed by histology, transmission electron microscopy, and real time reverse transcription-polymerase chain reaction. Colonocyte differentiation was determined by protein kinase C zeta (PKCzeta) immunofluorescence and western blotting, and alkaline phosphatase activity assay.

RESULTS

Acute stress induced a three day delayed increase in colonic paracellular permeability which involved mast cell degranulation and overproduction of IFN-gamma. The colonic epithelial barrier was morphologically altered and expression of mRNA encoding tight junction proteins ZO-2 and occludin was decreased. Moreover, three days after acute stress, colonocyte differentiation was reduced, as shown by decreased expression of both PKCzeta isotype and alkaline phosphatase.

CONCLUSION

These data highlight new mechanisms whereby an acute stress acts on the gastrointestinal tract by inducing alterations in colonocyte differentiation and decreased expression of mRNA encoding tight junction proteins. Thus phenotypic changes in colonocytes could pave the way for stress related intestinal disorders.

Quantification of mast cells in different stages of human periodontal disease

OBJECTIVE AND METHODS

Among the cells involved in immune and inflammatory responses in periodontal disease, mast cells have been shown to be capable of generating a large number of biologically active substances. The present study was undertaken to identify and quantify the presence of mast cells in different stages of human periodontal disease using histochemical (toluidine blue) and immunohistochemical (tryptase-positive mast cells) techniques.

RESULTS

Mast cell densities (cells per mm(2)) were significantly increased in chronic periodontitis/gingivitis lesions compared with clinically healthy gingival tissues (Health) uniquely by immunohistochemical technique. Interestingly, mast cells were distributed specially in close apposition to mononuclear cells.

CONCLUSIONS

In human periodontal disease there is an increase in the number of mast cells that may be participating either in the destructive events or in the defense mechanism of periodontal disease via secretion of cytokines, including perpetuation of the Th2 response, and cellular migration and healing processes.

Comparative immunohistochemical study of the presence of mast cells in apical granulomas and periapical cysts: possible role of mast cells in the course of human periapical lesions

Cells other than macrophages and lymphocytes have recently been shown capable of producing cytokines and mediators. Among these are mast cells, a cell population now recognized for its immunoregulatory properties. Little is known about the complex interactions between cells, cytokines, and other inflammatory elements in periapical lesions. The objective of this investigation was to determine the immunohistochemical pattern of expression of mast cells tryptase in periapical lesions based on study of 20 apical granulomas and 20 periapical cysts. Microscopic analysis revealed mast cells to be present in greater numbers in periapical cysts than in apical granulomas, and in cysts were more numerous in regions of active inflammation. Mast cells tended to be more common in the peripheral regions of both periapical lesions, and were often found in close proximity to lymphocytes. These findings lead us to propose a functional relationship between these two cell populations that may facilitate elicitation of an immune response contributory to the pathogenesis of periapical lesions.