The Cell Wall Fraction from Fonsecaea pedrosoi Stimulates Production of Different Profiles of Cytokines and Nitric Oxide by Murine Peritoneal Cells In Vitro

Chromoblastomycosis is a chronic, suppurative and granulomatous mycosis whose main etiologic agent is the fungus Fonsecaea pedrosoi. The severity of chromoblastomycosis clinical manifestations correlates with the Th1 or Th2 immune response, and an efficient cellular immune response depends on the interaction between immune cells and the cell wall of the fungi, which is able to promote this activation. The objective of this study was to analyze the influence of cell wall fractions of Fonsecaea pedrosoi on the activation of peritoneal phagocytes obtained from mice. Our results revealed that after 4 h of inoculation with fungal cell wall components, there was a cell migration predominantly comprised of neutrophils followed, after 72 h, by migration of the macrophages. After 4 h, the F2 fraction caused increased production of nitric oxide in phagocytes, but this effect was not observed in the phagocytes after 72 h. The F1 fraction stimulated production of IL-12 in cells that migrated after 72 h, while the inactivated fungus and the F2 fraction led to production of IL-10. The F2 fraction decreased the rate of phagocytosis and increased the production of IL-10. Our results suggest that the F2 fraction and its components caused an important disruption of microbicidal mechanisms negatively modulating the immune response and favoring the persistence of the fungus.