title: Cryptosporidium parvum induces B7-H1 expression in cholangiocytes by down-regulating microRNA-513.
abstract: Expression of B7 costimulatory molecules represents an important compartment of immune response of epithelial cells after microbial infection. We report here that the protozoan parasite Cryptosporidium parvum induced B7-H1 expression in cultured human cholangiocytes. Induced expression of B7-H1 was identified in cells after exposure to infective C. parvum parasite or parasite lysate. Interestingly, the level of microRNA-513 (miR-513) was reduced in cells after exposure to C. parvum, which resulted in a relief of 3' untranslated region-mediated translational suppression of B7-H1. Overexpression of miR-513 through transfection of miR-513 precursor inhibited C. parvum-induced B7-H1 protein expression. Moreover, enhanced apoptotic cell death was identified in activated human T cells after coculture with C. parvum-infected cholangiocytes. The apoptosis of activated T cells was partially blocked by a neutralizing antibody to B7-H1 or transfection of cholangiocytes with miR-513 precursor. These data suggest a role of miR-513 in regulating B7-H1 expression by cholangiocytes in response to C. parvum infection.
authors.affiliation: Department of Medical Microbiology and Immunology, Creighton University Medical Center, Omaha, Nebraska, USA.
authors.forename: Ai-Yu
authors.initials: AY
authors.lastname: Gong
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.forename: Guoku
authors.initials: G
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Danuta
authors.initials: D
authors.lastname: Sosnowska
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Drescher
authors.forename: Haidong
authors.initials: H
authors.lastname: Dong
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Chen
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis; D060890:B7-H1 Antigen; D001652:Bile Ducts / Q000166:cytology* / Q000469:parasitology; D002478:Cells, Cultured; D018920:Coculture Techniques; D016785:Cryptosporidium parvum / Q000472:pathogenicity*; D015536:Down-Regulation; D004847:Epithelial Cells / Q000378:metabolism* / Q000469:parasitology; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D013601:T-Lymphocytes / Q000469:parasitology
chemical_list: D015703:Antigens, CD; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C546275:MIRN513A1 microRNA, human; D035683:MicroRNAs