Studies of the mechanisms of adhesion and cytokine modulation during interaction of epithelial cells and pathogenic fungi

Abstract

Several studies about interaction of fungi of medical importance with host were performed using myeloid cells, which include macrophages, dendritic cells and neutrophils. By acting as structural barrier, lung epithelial cells constitute one of the first mechanisms of defense against inhaled particles and microorganisms. Besides, several groups have demonstrated that bacteria, fungi and other stimuli promote the expression of cytokines, chemokines and receptors in epithelial cells from different sources. Therefore, epithelial cells may participate in innate immunity, modulating host inflammatory response.The importance of epithelial cells in Candida albicans infection is more evident today. On the other hand, studies about interaction of epithelial cells with Paracoccidioides brasiliensis or Histoplasma capsulatum are still incipient. In this manner, the goals of this project are: i) analysis of the involved mechanisms in cytokine secretion by human epithelial cells, during infection with yeasts of P. brasiliensis or H. capsulatum; ii) characterization of proteases, isolated from P. brasiliensis, that degrade interleukin (IL)-6 and IL-8; and, iii) analysis of the mechanisms of adhesion and/or invasion of H. capsulatum yeasts in human epithelial cells. (AU)