Helicobacter pylori-induced Genotoxic Damage in Human B Lymphocytes

Abstract

Background

Helicobacter pylori (H. pylori) is recognized as the causative agent of peptic and duodenal ulcers, gastric adenocarcinoma, and low-grade mucosa-associated lymphoid tissue (MALT) lymphoma. In the present study, we investigate the genotoxic damage of lysates of H. pylori in human B lymphocytes.

Materials and Methods 

Human B lymphocytes were treated with 0, 10, 20, and 30 µg/L of total protein concentration of lysates obtained from H. pylori isolates from dyspeptic patients. Direct H. pylori-induced DNA damage was investigated by the in vitro cytokinesis-block cytokinesis-assay which detects chromosomal fragments and maldistributed whole chromosomes.

Results 

The total mean micronuclei number  (tMMN) observed per 1000 binucleus B cells significantly correlated with increasing protein concentration of H. pylori lysates (12.43 ± 1.91) when compared with the control (3.26 ± 0.48).

Conclusion

This study provides evidence of the direct effect of H. pylori in chromosomal breakage of human B lymphocytes, which might lead to the development of abnormal B cells. Long-term infection by H. pylori has been implicated in epithelial cell damage as a result of continuous induction of the immune system by bacterial antigens. However, the results of this study propose that persistent H. pylori infection could also directly damage B lymphocyte DNA from which gastric MALT  lymphoma arises.