Characteristics of vacuolating toxin produced by Helicobacter pylori.
OBJECTIVE
We sought a good indicator cell line to use in detecting the vacuolating toxin produced by Helicobacter pylori and in examining the characteristics of the toxin.


METHODS
Using five cell lines [baby hamster kidney (BHK-21), human amnion (FL), human uterine cancer (HeLa), rabbit kidney (RK-13) and African green monkey kidney (Vero)], cytotoxicity assays were performed with 33 H. pylori strains. To analyse the proteins produced by toxigenic and non-toxigenic strains, immunoblotting was done with the sera of patients with gastroduodenal diseases.


RESULTS
When RK-13, FL, Vero, BHK-21 and HeLa cells were used for the assay, 73, 61, 27, 27 and 21% of strains, respectively, were toxigenic. The vacuolating toxin is sensitive to heat at 70 degrees C. By immunoblot analysis, under non-denaturing conditions, immune sera recognized proteins with molecular weights of 600,000 and 500,000 in the toxigenic but not in the non-toxigenic strains.


CONCLUSIONS
H. pylori produces vacuolating toxin, which is a heat-sensitive protein at 70 degrees C and is easily detectable by cytotoxicity assay using the RK-13 cell line. Toxigenic H. pylori strains produce various proteins, including this toxin, which are recognized by sera from patients with gastroduodenal diseases.
Kamiya
S
S
Department of Microbiology, Kyorin University School of Medicine, Mitaka, Japan.
Kai
M
M
Ozawa
A
A
Kobayashi
H
H
Shirai
T
T
Harasawa
S
S
Miwa
T
T
D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000633:toxicity; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000633:toxicity; D001681:Biological Assay; D002460:Cell Line; D006224:Cricetinae; D003603:Cytotoxins / Q000096:biosynthesis* / Q000633:toxicity; D005767:Gastrointestinal Diseases / Q000097:blood; D000882:Haplorhini; D016480:Helicobacter pylori / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D015151:Immunoblotting; D011817:Rabbits
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; C074689:VacA protein, Helicobacter pylori