Effect of exposure to cigarette smoke in a murine model in the reactivation of paracoccidioidomycosis

• Grant number: 16/03914-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2016
• End date: February 28, 2017
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Gil Benard
• Grantee: Thais Martins de Jesus
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Paracoccidioidomycosis (PCM) is a systemic mycosis endemic in Latin America. Clinical manifestations of the disease usually resolve spontaneously; however, the fungus may persist in a quiescent focus with the subsequent development of the disease by endogenous reactivation, an event that may coincide with changes in the pattern of the host immune system. In this regard, because of the high frequency of tobacco use among PCM patients, which exceeds 93%, smoking appears to be a risk factor for the development of the mycosis. Moreover, previous studies have demonstrated the immunomodulatory effects of smoking by acetilcolinérgica efferent pathway of the vagus nerve, which signals to peripheral tissues via nicotinic acetylcholine receptors interrupting the production of proinflammatory cytokines by alveolar macrophages. In addition, while some studies suggest that pulmonary fibrotic lesions are due to a persistent antigenic stimulation, others point to smoking as the leading cause of the disability and functional changes observed in patients with PCM. Finally, the diagnosis of PCM is established by direct visualization of Paracoccidioides spp., under the microscope; histopathology preparation and confirmed by isolation of the fungus by culture or indirectly by serological techniques. Large therapeutic options are available for patients with PCM, including sulfonamide derivatives, amphotericin B and azole.