Fibrosis and expression of mast cells peptidase: chymase and tryptase in oral paracoccidioidomycosis lesions (55.25)

Abstract

Abstract Mast cells belong to the innate immune system, which provides the first line of defense against tissue damage. Tryptases and chymases are mast cells peptidases that promote inflammation, matrix destruction, and tissue remodeling by several mechanisms. They also modulate immune responses by hydrolyzing chemokines and cytokines. Oral lesions in Paracoccidioidomycosis(PCM), microscopically shows granulomatous inflammatory reaction with giant cells, macrophages, lymphocytes, plasma cells and mast cells. Mast cells were seen in PCM, but their participation and interaction with other cells remains to be determined. This study evaluated in situ expression of mast cell peptidase and fibrosis on oral lesions of PCM patients. Fifteen oral biopsies from patients with clinical and histopathological diagnosis of oral PCM and thirteen biospies from normal oral mucous (control group) were analyzed. Fibrosis was significantly higher in disorganized granuloma when compared to controls. Indirect immunohistochemistry was used to evaluate the expression of peptidase chymase and tryptase. The number of immunostained cells for chymase and tryptase was significantly higher in control group, when compared to the Pmycosis patients (p<0.025). The down modulation of chymase and tryptase expression and the increase fibrosis in PCM oral lesion may be a consequence of inflammatory process induced by the presence of fungus and also are potentially involved in the regulation of immune response.