Cryptosporidium parvum induces B7-H1 expression in cholangiocytes by down-regulating microRNA-513.
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.
Gong
Ai-Yu
AY
Department of Medical Microbiology and Immunology, Creighton University Medical Center, Omaha, Nebraska, USA.
Zhou
Rui
R
Hu
Guoku
G
Liu
Jun
J
Sosnowska
Danuta
D
Drescher
Kristen M
KM
Dong
Haidong
H
Chen
Xian-Ming
XM
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
D015703:Antigens, CD; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C546275:MIRN513A1 microRNA, human; D035683:MicroRNAs