title: Expression of interferon gamma and proinflammatory cytokines in the cecal mucosa of rats experimentally infected with Blastocystis sp. strain RN94-9.
abstract: Blastocystis hominis is a zoonotic intestinal protozoan parasite whose pathogenic potential is still controversial. The aim of the present study was to clarify the pathogenicity of Blastocystis parasites in rats. Oral inoculation with 1 x 10(5) cysts of Blastocystis sp. strain RN94-9 in rats resulted in chronic infection in the cecum at least until 4 weeks after infection. Histological examination revealed neither mucosal sloughing nor inflammatory cell infiltration but showed a slight but significant increase in goblet cell numbers in the cecal mucosa 1-3 weeks post-infection. Differential staining of acidic and neutral mucins by the alcian blue-periodic acid-Schiff method showed that the predominantly increased cells were neutral mucin(+) but not acidic mucin(+) goblet cells. Reverse transcription real-time polymerase chain reaction studies demonstrated significant upregulation of the expression of interferon-gamma, interleukin (IL)-12, and tumor necrosis factor alpha, but not IL-6 or granulocyte-macrophage colony-stimulating factor, in the cecal mucosa at 2 and/or 3 weeks post-infection. The induction of local host responses, including mild goblet cell hyperplasia, and significant upregulation of type-1 and proinflammatory cytokines, suggest that Blastocystis sp. strain RN94-9 is a weakly pathogenic organism that could elicit proinflammatory as well as protective responses in local tissues.
authors.affiliation: Department of Biological Sciences, Nara Women's University, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Iguchi
authors.forename: Hisao
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamada
authors.forename: Isao
authors.initials: I
authors.lastname: Kimata
authors.forename: Naoki
authors.initials: N
authors.lastname: Arizono
mesh_terms: D000818:Animals; D016844:Blastocystis / Q000276:immunology* / Q000472:pathogenicity; D016776:Blastocystis Infections / Q000276:immunology* / Q000473:pathology; D002432:Cecum / Q000276:immunology* / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D020397:Goblet Cells / Q000473:pathology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000473:pathology; D008297:Male; D009077:Mucins / Q000032:analysis; D051381:Rats
chemical_list: D016207:Cytokines; D009077:Mucins