title: Identification of small RNAs in extracellular vesicles from the commensal yeast Malassezia sympodialis.
abstract: Malassezia is the dominant fungus in the human skin mycobiome and is associated with common skin disorders including atopic eczema (AE)/dermatitis. Recently, it was found that Malassezia sympodialis secretes nanosized exosome-like vesicles, designated MalaEx, that carry allergens and can induce inflammatory cytokine responses. Extracellular vesicles from different cell-types including fungi have been found to deliver functional RNAs to recipient cells. In this study we assessed the presence of small RNAs in MalaEx and addressed if the levels of these RNAs differ when M. sympodialis is cultured at normal human skin pH versus the elevated pH present on the skin of patients with AE. The total number and the protein concentration of the released MalaEx harvested after 48 h culture did not differ significantly between the two pH conditions nor did the size of the vesicles. From small RNA sequence data, we identified a set of reads with well-defined start and stop positions, in a length range of 16 to 22 nucleotides consistently present in the MalaEx. The levels of small RNAs were not significantly differentially expressed between the two different pH conditions indicating that they are not influenced by the elevated pH level observed on the AE skin.
authors.affiliation: Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway.
authors.forename: Simon
authors.initials: S
authors.lastname: Rayner
authors.affiliation: Translational Immunology Unit, Department of Medicine Solna, Karolinska Institutet and University Hospital Stockholm, Sweden.
authors.forename: Sören
authors.initials: S
authors.lastname: Bruhn
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, and Sachs' Children and Youth Hospital, Södersjukhuset, SE-118 83 Stockholm, Sweden.
authors.forename: Helen
authors.initials: H
authors.lastname: Vallhov
authors.affiliation: Translational Immunology Unit, Department of Medicine Solna, Karolinska Institutet and University Hospital Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Andersson
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: R Blake
authors.initials: RB
authors.lastname: Billmyre
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, and Sachs' Children and Youth Hospital, Södersjukhuset, SE-118 83 Stockholm, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Scheynius
mesh_terms: D000818:Animals; D016207:Cytokines / Q000378:metabolism; D003881:Dermatomycoses / Q000235:genetics / Q000382:microbiology*; D055354:Exosomes / Q000235:genetics*; D000067128:Extracellular Vesicles / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007073:Immunoglobulin E / Q000097:blood; D008290:Malassezia / Q000235:genetics*; D020733:RNA, Small Cytoplasmic / Q000235:genetics*; D012867:Skin / Q000382:microbiology / Q000473:pathology*; D013559:Symbiosis; D014010:Tinea Versicolor / Q000235:genetics / Q000382:microbiology*
chemical_list: D016207:Cytokines; D020733:RNA, Small Cytoplasmic; D007073:Immunoglobulin E