Vacuolating cytotoxin in Helicobacter pylori water-soluble proteins upregulates chemokine expression in human eosinophils via Ca2+ influx, mitochondrial reactive oxygen intermediates, and NF-kappaB activation.
Helicobacter pylori-infected gastric mucosa is characterized by infiltration of inflammatory cells such as neutrophils and eosinophils. However, little information is available on the relationship between H. pylori virulence factors and chemokine expression in eosinophils. This study investigates the role of vacuolating cytotoxin (VacA) in chemokine expression from human eosinophils. Eosinophils were isolated from the peripheral blood of healthy volunteers using a magnetic cell separation system. VacA(+) H. pylori water-soluble proteins (WSP) induced higher expression of interleukin-8, growth-related oncogene alpha, monocyte chemotactic protein 1, and RANTES (regulated on activation, normal, T-cell expressed and secreted) than Vac(-) WSP in human eosinophils, as assessed by quantitative reverse transcription-PCR and enzyme-linked immunosorbent assay. Purified VacA not only increased chemokine expression but also activated p65/p50 NF-kappaB heterodimers and phosphorylated IkappaB kinase (IKK) alpha/beta signals in human eosinophils. Inhibition of NF-kappaB and IKK significantly decreased the chemokine expression in VacA-stimulated eosinophils. Furthermore, VacA-induced NF-kappaB activation and chemokine release from eosinophils were dependent on Ca(2+) influx and mitochondrial generation of reactive oxygen intermediates (ROI). These results suggest that NF-kappaB and IKK signals via Ca(2+) influx and mitochondrial ROI play a role in the up-regulation of chemokine expression in eosinophils stimulated with H. pylori VacA.
Kim
Jung Mogg
JM
Department of Microbiology, Hanyang University College of Medicine, 17 Haengdang-dong, Sungdong-gu, Seoul 133-791, South Korea. jungmogg@hanyang.ac.kr
Kim
Joo Sung
JS
Lee
Jin Young
JY
Kim
Yeong-Jeon
YJ
Youn
Ho-Joo
HJ
Kim
In Young
IY
Chee
Young Joon
YJ
Oh
Yu-Kyoung
YK
Kim
Nayoung
N
Jung
Hyun Chae
HC
Song
In Sung
IS
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D018925:Chemokines / Q000378:metabolism*; D004804:Eosinophils / Q000276:immunology / Q000378:metabolism*; D016480:Helicobacter pylori / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012995:Solubility; D015854:Up-Regulation; D014867:Water
D001426:Bacterial Proteins; D018925:Chemokines; D016328:NF-kappa B; D017382:Reactive Oxygen Species; C074689:VacA protein, Helicobacter pylori; D014867:Water; D051550:I-kappa B Kinase; D002118:Calcium