Potent neutralization of vacuolating cytotoxin (VacA) of Helicobacter pylori by immunoglobulins against the soluble recombinant VacA.
BACKGROUND
The recombinant vacuolating cytotoxin (rVacA) of Helicobacter pylori that retains native conformational epitopes was evaluated as a vaccine antigen for anti-H. pylori treatment.


METHODS
s1m1 vacA gene fraction encoding the mature VacA protein was expressed as a soluble protein in E. coli at low temperature. The efficacy of anti-rVacA antibody against VacA or H. pylori was assessed in vitro using AGS cells and in vivo using a murine model.


RESULTS
The rabbit antisera against rVacA completely neutralized the vacuolating activity and partially inhibited the cell death induced by VacA in AGS cells. Oral immunization of C57BL/6 mice with rVacA plus CpG-oligodeoxynucleotide (ODN) as an ajuvant stimulated specific anti-VacA antibody and mucosal immune responses which correlated with decreased systemic immune responses and gastric urease activities (p>0.05).


CONCLUSIONS
The rVacA antigen possessing conformational epitopes may have potential as a vaccine component and may be useful in serological and histopathological analysis.
Ki
Mi-Ran
MR
College of Veterinary Medicine, Kyungpook National University, Buk-ku, Daegu City, Republic of Korea.
Hong
Il-Hwa
IH
Park
Jin-Kyu
JK
Hong
Kyung-Sook
KS
Hwang
Ok-Kyung
OK
Han
Jung-Yuan
JY
Ji
Ae-Ri
AR
Park
Se-Il
SI
Lee
Seung-Keun
SK
Yoo
Sung-Eun
SE
Jeong
Kyu-Shik
KS
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000276:immunology* / Q000821:virology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007114:Immunization; D015151:Immunoblotting; D051379:Mice; D008810:Mice, Inbred C57BL; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D013274:Stomach Neoplasms / Q000097:blood / Q000276:immunology* / Q000821:virology; D014407:Tumor Cells, Cultured; D014617:Vacuoles / Q000378:metabolism*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; C074689:VacA protein, Helicobacter pylori