title: Sequence and apoptotic activity of VacA cytotoxin cloned from a Helicobacter pylori Thai clinical isolate.
abstract: The vacuolating cytotoxin VacA produced by Helicobacter pylori induces the formation of large cytoplasmic vacuoles in host gastric epithelial cells as well as a release of cytochrome C from mitochondria resulting in cell apoptosis. Considerable sequence diversity in VacA relating to different degrees of disease severity is observed with clinical samples from a multitude of geographic places. In this study we describe expression in Escherichia coli, purification to homogeneity and in vitro assay of its apoptotic activity of a VacA toxin from a H. pylori isolate of a Thai patient with gastrointestinal lymphoma. Sequencing revealed that the deduced amino acid sequence of the cloned Thai isolate VacA is similar to H. pylori s1/m2 type strains. The percent sequence similarity to the model strain 60190 was lower due to the presence of extra amino acids in the mid (m) region. The purified VacA toxin exhibited significant apoptotic activity on both T84 and MDCK epithelial cell lines, as revealed by DAPI staining, whereby the observed activity was significantly higher on MDCK cells. These findings could relate to a modulation of VacA activity on host cells in the Thai isolate-VacA toxin that may differ from those of the model strain.
authors: Department of Pharmacy, Division of Pharmacology, University of Malakand, Khyber Pakhtunkhwa 18550, Pakistan ; Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand.
authors: Muhammad
authors: M
authors: Junaid
authors: Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand.
authors: Sarbast
authors: S
authors: Al-Gubare
authors: Department of Physiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Muhammad
authors: M
authors: Yousef
authors: Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors: Mathukorn Na
authors: MN
authors: Ubol
authors: Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand.
authors: Somphob
authors: S
authors: Leetachewa
authors: Department of Physiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Chatchai
authors: C
authors: Muanprasat
authors: Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand.
authors: Chanan
authors: C
authors: Angsuthanasombat
authors: Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
authors: Wanpen
authors: W
authors: Chaicumpa
authors: Department of Pharmacology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar 25000, Pakistan.
authors: Niaz
authors: N
authors: Ali
authors: Bacterial Protein Toxin Research Cluster, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand.
authors: Gerd
authors: G
authors: Katzenmeier
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001426:Bacterial Proteins / Q000235:genetics / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003603:Cytotoxins / Q000235:genetics / Q000494:pharmacology*; D004285:Dogs; D016480:Helicobacter pylori / Q000235:genetics*; D061985:Madin Darby Canine Kidney Cells; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D003603:Cytotoxins; D011994:Recombinant Proteins; C074689:VacA protein, Helicobacter pylori