Open AccessCaspase‐dependent apoptosis of the HCT‐8 epithelial cell line induced by the parasite Giardia intestinalis
Author(s) -
Panaro Maria Antonietta,
Cianciulli Antonia,
Mitolo Vincenzo,
Mitolo Carlo Ivan,
Acquafredda Angela,
Brandonisio Olga,
Cavallo Pasqua
Publication year - 2007
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2007.00304.x
Subject(s) - biology , apoptosis , dna fragmentation , caspase , poly adp ribose polymerase , programmed cell death , enterocyte , cell culture , microbiology and biotechnology , small intestine , dna , biochemistry , polymerase , genetics
Giardia intestinalis is a flagellated protozoan which causes enteric disease worldwide. Giardia trophozoites infect epithelial cells of the proximal small intestine and can cause acute or chronic diarrhea. The mechanism of epithelial injury in giardiasis remains unknown. A number of enteric pathogens, including protozoan parasites, are able to induce enterocyte apoptosis. The aim of this work was to assess whether G . intestinalis strain WB clone C6 is able to induce apoptosis in the human intestinal epithelial cell line HCT‐8, and to investigate the role of caspases in this process. Results demonstrated that the parasite induces cell apoptosis, as confirmed by DNA fragmentation analysis, detection of active caspase‐3 and degradation of the caspase‐3 substrate PARP [poly(ADP‐ribose) polymerase]. Furthermore, G . intestinalis infection induces activation of both the intrinsic and the extrinsic apoptotic pathways, down‐regulation of the antiapoptotic protein Bcl‐2 and up‐regulation of the proapoptotic Bax, suggesting a possible role for caspase‐dependent apoptosis in the pathogenesis of giardiasis.