Immune response to a 26-kDa protein, alkyl hydroperoxide reductase, in Helicobacter pylori-infected Mongolian gerbil model.

BACKGROUND

The host immune response is thought to play an important role in the outcome of Helicobacter pylori infection. The successful development of the H. pylori-infected Mongolian gerbil model that mimics human disease has enabled study of the antibody response against H. pylori antigens.

MATERIALS AND METHODS

Serum samples from ulcer and carcinogenesis models of H. pylori-infected gerbils were used to screen for H. pylori antigens that cause a humoral immune response in the infected hosts. H. pylori alkyl hydroperoxide reductase (AhpC) is one such antigen on which we report here. The tsaA gene encoding AhpC was amplified by PCR from H. pylori ATCC 43504 strain, cloned into pMAL(TM)-c2 expression vector and expressed in Escherichia coli. Maltose-binding protein fusion protein (MBP-AhpC) was purified by a MBP affinity column. Using purified recombinant AhpC protein as an antigen, the antibody response and changes of antibody levels against AhpC in the gerbil models were studied by Western blotting and ELISA.

RESULTS

Antibody against AhpC was negative in the early stages of infection, and became positive in the gerbils with the emergence of gastric diseases such as chronic active gastritis, gastric ulcer and gastric cancer. The antibody levels (ELISA) increased gradually over time and were higher in gerbils with gastric ulcer than that in gerbils without ulcers.

CONCLUSIONS

Use of the gerbil model that mimics human H. pylori infection is likely to provide insights into the role of H. pylori-specific antigens possibly related to the subsequent development of gastric diseases.