Species-Specific Immunological Reactivities Depend on the Cell-Wall Organization of the Two , and .

Although belong to the same genus, is primarily involved in invasive pulmonary infection, whereas is a common cause of superficial infection. In this study, we compared conidia (the infective propagules) of these two species. In immunocompetent mice, intranasal inoculation with conidia of resulted in significantly higher inflammatory responses in the lungs compared to mice inoculated with conidia. assays revealed that the dormant conidia of , unlike dormant conidia, are immunostimulatory. The conidial surface of was covered by a rodlet-layer, while that of were presented with exposed polysaccharides. harbored significantly higher number of proteins in its conidial cell wall compared to conidia. Notably, β-1,3-glucan in the conidial cell-wall showed significantly higher percentage of branching compared to that of . The polysaccharides ensemble of conidial cell wall stimulated the secretion of proinflammatory cytokines, and conidial cell wall associated proteins specifically stimulated IL-8 secretion from the host immune cells. Furthermore, the two species exhibited different sensitivities to antifungal drugs targeting cell wall polysaccharides, proposing the efficacy of species-specific treatment strategies. Overall, the species-specific organization of the conidial cell wall could be important in establishing infection by the two species.