Original Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 28, 2011; 17(32): 3691-3699
Published online Aug 28, 2011. doi: 10.3748/wjg.v17.i32.3691
Induction of CD69 expression by cagPAI-positive Helicobacter pylori infection
Naoki Mori, Chie Ishikawa, Masachika Senba
Naoki Mori, Chie Ishikawa, Department of Microbiology and Oncology, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan
Masachika Senba, Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
Naoki Mori, Department of Internal Medicine, Omoromachi Medical Center, 1-3-1 Uenoya, Naha, Okinawa 900-0011, Japan
Chie Ishikawa, Transdisciplinary Research Organization for Subtropics and Island Studies, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
Author contributions: Mori N and Ishikawa C performed the research; Senba M performed the immunohistochemistry; Mori N designed the study and wrote the manuscript.
Correspondence to: Naoki Mori, MD, PhD, Department of Microbiology and Oncology, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan. naokimori50@gmail.com
Telephone: +81-98-8672116 Fax: +81-98-8612398
Received: January 12, 2011
Revised: March 1, 2011
Accepted: March 8, 2011
Published online: August 28, 2011
Abstract

AIM: To investigate and elucidate the molecular mechanism that regulates inducible expression of CD69 by Helicobacter pylori (H. pylori) infection.

METHODS: The expression levels of CD69 in a T-cell line, Jurkat, primary human peripheral blood mononuclear cells (PBMCs), and CD4+ T cells, were assessed by immunohistochemistry, reverse transcription polymerase chain reaction, and flow cytometry. Activation of CD69 promoter was detected by reporter gene. Nuclear factor (NF)-κB activation in Jurkat cells infected with H. pylori was evaluated by electrophoretic mobility shift assay. The role of NF-κB signaling in H. pylori-induced CD69 expression was analyzed using inhibitors of NF-κB and dominant-negative mutants. The isogenic mutants with disrupted cag pathogenicity island (cagPAI) and virD4 were used to elucidate the role of cagPAI-encoding type IV secretion system and CagA in CD69 expression.

RESULTS: CD69 staining was detected in mucosal lymphocytes and macrophages in specimens of patients with H. pylori-positive gastritis. Although cagPAI-positive H. pylori and an isogenic mutant of virD4 induced CD69 expression, an isogenic mutant of cagPAI failed to induce this in Jurkat cells. H. pylori also induced CD69 expression in PBMCs and CD4+ T cells. The activation of the CD69 promoter by H. pylori was mediated through NF-κB. Transfection of dominant-negative mutants of IκBs, IκB kinases, and NF-κB-inducing kinase inhibited H. pylori-induced CD69 activation. Inhibitors of NF-κB suppressed H. pylori-induced CD69 mRNA expression.

CONCLUSION: The results suggest that H. pylori induces CD69 expression through the activation of NF-κB. cagPAI might be relevant in the induction of CD69 expression in T cells. CD69 in T cells may play a role in H. pylori-induced gastritis.

Keywords: CD69; T cells; Helicobacter pylori; cag pathogenicity island; Nuclear factor-κB