Profile of cytokines in the lungs of BALB/c mice after intra-nasal infection with Histoplasma capsulatum mycelial propagules

Abstract

The host pulmonary response to the fungus Histoplasma capsulatum was evaluated, through the profile of cytokines detected by the MagPix magnetic beads platform in lung homogenates and by lung-granulomas formation, from mice intra-nasally infected with mycelial propagules (M-phase) of two virulent H. capsulatum strains, EH-46 and G-217B. Results highlight that mice lung inflammatory response depends on the H. capsulatum strain used, during the first step of the fungal infection. IL-1β and TNF-α increased their concentrations in mice infected with both strains. The highest levels of IL-6, IL-17, and IL-23 were found in EH-46-infected mice, whereas levels of IL-22 were variable at all post-infection times for both strains. Significant increases of IL-12, IFN-γ, IL-4, and IL-10 were associated to EH-46-infected mice. Histological lung findings from EH-46-infected mice revealed incipient and numerous well-developed granulomas, distributed in lung-lobes at the 14th and the 21st days after infection, according to cytokine profiles.

Keywords: Cytokines; H. capsulatum; Intra-nasal infection; Mycelial propagules.