The role of prostaglandins in the experimental infection by Histoplasma capsulatum.

Author(s)

Priscilla Aparecida Tartari Pereira

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2009-08-13

Examining board members

Lucia Helena Faccioli; Marta Chagas Monteiro; Gloria Emilia Petto de Souza

• Advisor: Lucia Helena Faccioli

Abstract

The Histoplasmosis is a chronic granulomatosas disease whose etiologic agent is pathogenic dimorphic fungus Histoplasma capsulatum. Infection occurs mainly by fungal inhalation that reaches the alveoli, where if transforms into leavenings that are responsible for pathogenic diseases. The cellular immunity of the host determines the degree of the clinical manifestations in histoplasmosis, being the interaction between cells T and macrophages, basic for the control of the infection and eradication of the H. capsulatum. Recently, our group of research demonstrated the participation of leukotrienes in the mechanisms of defense of the host during the Histoplasmosis. Beyond this important lipid mediator who participates in the immune reply against H. capsulatum. In this work, we describe another involved mediator, the prostaglandin. In the present work, we demonstrate that the prostaglandins contribute for pathogenic of the disease, being that during its inhibition with celecoxib it resulted in the survival of up to 80% of the infection-mice with inoculum lethal of H. capsulatum, in contrast with 100% of mortality infection-mice. Moreover, the inhibition of prostaglandins resulted in the reduction (i) of the synthesis of pro-inflammatory cytokines and the cellular immune response and (ii) in the migration of neutrophils and macrophages. For other hand, increased (iii) of cells TCD4+ in the lung, (iv) of the nitric oxide synthesis, (v) of phagocytosis of yeast of H. capsulatum for alveolar macrophages and (vi) of the synthesis of LTB4. Our results suggest that prostaglandins have important role in pathogenic in the infection for H. capsulatum, modulating the host immune response. (AU)