AUTHOR=Wong Sarah Sze Wah , Venugopalan Lakshmi Prabha , Beaussart Audrey , Karnam Anupama , Mohammed Mohammed Razeeth Shait , Jayapal Jeya Maheshwari , Bretagne Stéphane , Bayry Jagadeesh , Prajna Lalitha , Kuppamuthu Dharmalingam , Latgé Jean-Paul , Aimanianda Vishukumar 

TITLE=Species-Specific Immunological Reactivities Depend on the Cell-Wall Organization of the Two Aspergillus, Aspergillus fumigatus and A. flavus

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.643312

DOI=10.3389/fcimb.2021.643312

ISSN=2235-2988

ABSTRACT=<p>Although belong to the same genus, <italic>Aspergillus fumigatus</italic> is primarily involved in invasive pulmonary infection, whereas <italic>Aspergillus flavus</italic> is a common cause of superficial infection. In this study, we compared conidia (the infective propagules) of these two <italic>Aspergillus</italic> species. In immunocompetent mice, intranasal inoculation with conidia of <italic>A. flavus</italic> resulted in significantly higher inflammatory responses in the lungs compared to mice inoculated with <italic>A. fumigatus</italic> conidia. <italic>In vitro</italic> assays revealed that the dormant conidia of <italic>A. flavus</italic>, unlike <italic>A. fumigatus</italic> dormant conidia, are immunostimulatory. The conidial surface of <italic>A. fumigatus</italic> was covered by a rodlet-layer, while that of <italic>A. flavus</italic> were presented with exposed polysaccharides. <italic>A. flavus</italic> harbored significantly higher number of proteins in its conidial cell wall compared to <italic>A. fumigatus</italic> conidia. Notably, β-1,3-glucan in the <italic>A. flavus</italic> conidial cell-wall showed significantly higher percentage of branching compared to that of <italic>A. fumigatus</italic>. The polysaccharides ensemble of <italic>A. flavus</italic> 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 <italic>Aspergillus</italic> species.</p>