Interferon-gamma-induced apoptosis in host cells infected with Neospora caninum.
Interferon-gamma (IFN-gamma) has a crucial role for host defence against parasite infection. It is not clear, however, how IFN-gamma affects the parasite-infected host cells. The effect of IFN-gamma on Neospora caninum-infected cells was investigated in murine fibroblasts and canine kidney cells in vitro. In the presence of IFN-gamma, the viability of the infected host cell was decreased and apoptotic cell death occurred, as analysed by DNA stainings with propidium iodide and a terminal deoxy-nucleotidyltransferase-mediated dUTP-biotin nick end labelling (TUNEL) and DNA fragmentation. The percentage of apoptotic cells depended on the dose of IFN-gamma. Flow cytometric analysis indicated a significant increase of FasL expression on the IFN-gamma treated cells following N. caninum infection. Moreover, IFN-gamma treatment down-regulated Bcl-2 expression in the cells cultured with N. caninum while parasite infection up-regulated Bcl-2 expression. The present study suggests that the IFN-gamma induced increases of FasL expression and down-regulated Bcl-2 expression in N. caninum-infected cells are associated with apoptosis in vitro.
Nishikawa
Y
Y
National Research Center for Protozoan Diseases, Obihiro University, Hokkaido, Yapan.
Mishima
M
M
Nagasawa
H
H
Igarashi
I
I
Fujisaki
K
K
Otsuka
H
H
Mikami
T
T
D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D016367:Baculoviridae / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D003048:Coccidiosis / Q000276:immunology / Q000662:veterinary*; D053938:DNA Fragmentation / Q000276:immunology; D004285:Dogs; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D019254:Genes, bcl-2 / Q000276:immunology; D020287:In Situ Nick-End Labeling; D007371:Interferon-gamma / Q000276:immunology* / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D051379:Mice; D018688:Neospora / Q000254:growth & development / Q000276:immunology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins; D019014:fas Receptor / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D019014:fas Receptor; D007371:Interferon-gamma