The role of eosinophils during Cryptococcus gattii infection

Cryptococcosis is a potentially systemic invasive mycosis responsible for approximately 625,000 deaths annually. Species from the Cryptococcus neoformans/C. gattii complex are the primary etiological agents of the disease, with lung tissue generally serving as the primary site of infection. Eosinophils are prominent cells in bronchopulmonary mycoses. However, the exact role of eosinophils during fungal infections, particularly in pulmonary cryptococcosis, remains poorly understood. Previous work from our group has shown that pulmonary infection with C. gattii is associated with a type 2 inflammatory response, characterized by increased eosinophils, elevated IL-4 and IL-5 levels, and significant fibrosis caused by the deposition of thick collagen fibers. We hypothesize that eosinophils play a central role in the pulmonary inflammatory response caused by C. gattii. To investigate the contribution of this leukocyte population during C. gattii infection, we intratracheally inoculated 10⁴ yeasts into BALB/c wild-type (WT) and eosinophil-deficient (∆dblGATA1^-/-) mice. Our results indicate that ∆dblGATA1^-/- mice are more susceptible to C. gattii displaying higher mortality rate compared to infected BALB/c WT animals. Additionally, ∆dblGATA1^-/- mice exhibit higher clinical score two weeks post-infection. Further data are still needed to address our hypothesis, but the present results suggest a protective role for eosinophils during pulmonary C. gattii infection in the BALB/c mice model.