Contributions of Extracellular Vesicles to Fungal Biofilm Pathogenesis

Extracellular vesicles (EVs) are produced by all kingdoms of life and have been increasingly recognized as a key aspect of microbial pathogenicity. These membrane-bound compartments serve as secretory vehicles for the delivery of macromolecules to the extracellular environment. Studies over the past several decades have revealed that microbial EVs are highly suited to the biology and environmental context of the organism secreting them. Fungal EVs have been described in at least 12 species and have diverse functions. These functions include, but are not limited to, molecular transport across the cell wall, immunomodulation, cell-cell communication, export of virulence factors and nucleic acids, extracellular matrix (ECM) production, and induction of drug resistance. This chapter will explore the contributions of EVs to fungal pathogenesis and virulence, with a detailed focus on the role of C. albicans biofilm EVs in matrix biogenesis and antifungal resistance. Brief commentary on EV function in bacterial biofilms will also be provided for comparison, and suggestions for areas of future investigation in this field will be discussed.