Abstract
Helicobacter pylori now is recognized as an etiological agent in chronic superficial gastritis and peptic ulcer disease. Although only about 60% of H. pylori isolates produce an immunodominant 128-kDa antigen (CagA; cytotoxin- associated gene product), virtually all H. pylori-infected patients with duodenal ulceration develop a serologic response to the 128-kDa protein, which suggests an association of this gene with ulceration. The cloned cagA gene from H. pylori 84-183 was disrupted by insertion of a kanamycin resistance gene, and this inactivated cagA construct was introduced into H. pylori 84-183 by electrotranformation. Southern hybridization of kanamycin- resistant H. pylori transformants demonstrated that the wild-type cagA gene had been disrupted by insertion of the kanamycin cassette, and immunoblot analysis showed that the mutant strains no longer produced the 128-kDa CagA protein. Similar results were obtained when the cagA mutation was introduced by natural transformation into H. pylori 60190, a high-level toxin-producing strain. The cagA-negative H. pylori strains showed cytotoxin, urease, and phospholipase C activities, C3 binding, and adherence similar to those of the isogenic wild-type strains. These findings demonstrate that the cagA gene product does not affect the vacuolating cytotoxin activity of H. pylori.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2609-2613 |
| Number of pages | 5 |
| Journal | Infection and immunity |
| Volume | 62 |
| Issue number | 6 |
| State | Published - Jan 1 1994 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Immunology
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Mutation of the cytotoxin-associated cagA gene does not affect the vacuolating cytotoxin activity of Helicobacter pylori. / Tummuru, M. K R; Cover, T. L.; Blaser, Martin.
In: Infection and immunity, Vol. 62, No. 6, 01.01.1994, p. 2609-2613.Research output: Contribution to journal › Comment/debate
TY - JOUR
T1 - Mutation of the cytotoxin-associated cagA gene does not affect the vacuolating cytotoxin activity of Helicobacter pylori
AU - Tummuru, M. K R
AU - Cover, T. L.
AU - Blaser, Martin
PY - 1994/1/1
Y1 - 1994/1/1
N2 - Helicobacter pylori now is recognized as an etiological agent in chronic superficial gastritis and peptic ulcer disease. Although only about 60% of H. pylori isolates produce an immunodominant 128-kDa antigen (CagA; cytotoxin- associated gene product), virtually all H. pylori-infected patients with duodenal ulceration develop a serologic response to the 128-kDa protein, which suggests an association of this gene with ulceration. The cloned cagA gene from H. pylori 84-183 was disrupted by insertion of a kanamycin resistance gene, and this inactivated cagA construct was introduced into H. pylori 84-183 by electrotranformation. Southern hybridization of kanamycin- resistant H. pylori transformants demonstrated that the wild-type cagA gene had been disrupted by insertion of the kanamycin cassette, and immunoblot analysis showed that the mutant strains no longer produced the 128-kDa CagA protein. Similar results were obtained when the cagA mutation was introduced by natural transformation into H. pylori 60190, a high-level toxin-producing strain. The cagA-negative H. pylori strains showed cytotoxin, urease, and phospholipase C activities, C3 binding, and adherence similar to those of the isogenic wild-type strains. These findings demonstrate that the cagA gene product does not affect the vacuolating cytotoxin activity of H. pylori.
AB - Helicobacter pylori now is recognized as an etiological agent in chronic superficial gastritis and peptic ulcer disease. Although only about 60% of H. pylori isolates produce an immunodominant 128-kDa antigen (CagA; cytotoxin- associated gene product), virtually all H. pylori-infected patients with duodenal ulceration develop a serologic response to the 128-kDa protein, which suggests an association of this gene with ulceration. The cloned cagA gene from H. pylori 84-183 was disrupted by insertion of a kanamycin resistance gene, and this inactivated cagA construct was introduced into H. pylori 84-183 by electrotranformation. Southern hybridization of kanamycin- resistant H. pylori transformants demonstrated that the wild-type cagA gene had been disrupted by insertion of the kanamycin cassette, and immunoblot analysis showed that the mutant strains no longer produced the 128-kDa CagA protein. Similar results were obtained when the cagA mutation was introduced by natural transformation into H. pylori 60190, a high-level toxin-producing strain. The cagA-negative H. pylori strains showed cytotoxin, urease, and phospholipase C activities, C3 binding, and adherence similar to those of the isogenic wild-type strains. These findings demonstrate that the cagA gene product does not affect the vacuolating cytotoxin activity of H. pylori.
UR - http://www.scopus.com/inward/record.url?scp=0028307195&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028307195&partnerID=8YFLogxK
M3 - Comment/debate
C2 - 8188385
AN - SCOPUS:0028307195
VL - 62
SP - 2609
EP - 2613
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 6
ER -