title: Mast cells kill Candida albicans in the extracellular environment but spare ingested fungi from death.
abstract: Mast cells (MCs) reside in tissues that are common targets of Candida spp. infections, and can exert bactericidal activity, but little is known about their fungicidal activity. MCs purified from rat peritoneum (RPMC) and a clinical isolate of C. albicans, were employed. Ingestion was evaluated by flow cytometry (FACS) and optical microscopy. The killing activity was assayed by FACS analysis and by colony forming unit method. RPMC degranulation was evaluated by β-hexosaminidase assay and phosphatidylserine externalization by FACS. Phagocytosing RPMC were also analyzed by transmission electron microscopy. Herein, we show that the killing of C. albicans by RPMC takes place in the extracellular environment, very likely through secreted granular components. Ultrastructural analysis of the ingestion process revealed an unusual RPMC-C. albicans interaction that could allow fungal survival. Our findings indicate that MCs have a positive role in the defense mechanism against Candida infections and should be included among the cell types involved in host-defense against this pathogen.
authors.affiliation: Department of Life Science, University of Trieste, Trieste, via Valerio n° 28, 34127, Trieste, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Trevisan
authors.forename: Francesca
authors.initials: F
authors.lastname: Vita
authors.forename: Nevenka
authors.initials: N
authors.lastname: Medic
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Soranzo
authors.forename: Giuliano
authors.initials: G
authors.lastname: Zabucchi
authors.forename: Violetta
authors.initials: V
authors.lastname: Borelli
mesh_terms: D000818:Animals; D002176:Candida albicans / Q000502:physiology*; D045604:Extracellular Fluid / Q000166:cytology / Q000502:physiology*; D005260:Female; D008297:Male; D008407:Mast Cells / Q000502:physiology* / Q000648:ultrastructure; D010587:Phagocytosis / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar