High concentrations of human beta-defensin 2 in gastric juice of patients with Helicobacter pylori infection.
OBJECTIVE
Human beta-defensin (HBD)-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori (H pylori). We sought to determine HBD-1 and HBD-2 concentrations in gastric juice during H pylori infection.


METHODS
HBD-1 and HBD-2 concentrations were measured by radioimmunoassay in plasma and gastric juice of 49 H pylori-infected and 33 uninfected subjects and before and after anti-H pylori treatment in 13 patients with H pylori-associated gastritis. Interleukin (IL)-1beta and IL-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay (ELISA). Histological grades of gastritis were determined using two biopsy specimens taken from the antrum and corpus. Reverse phase high performance liquid chromatography (RP-HPLC) was used to identify HBD-2.


RESULTS
HBD-2 concentrations in gastric juice, but not in plasma, were significantly higher in H pylori-positive than -negative subjects, albeit the post-treatment levels were unchanged. Immunoreactivity for HBD-2 was exclusively identified in H pylori-infected mucosa by RP-HPLC. HBD-2 concentrations in gastric juice correlated with histological degree of neutrophil and mononuclear cell infiltration in the corpus. IL-1beta levels correlated with those of IL-8, but not HBD-2. Plasma and gastric juice HBD-1 concentrations were similar in H pylori-infected and uninfected subjects.


CONCLUSIONS
Our results place the beta-defensins, especially HBD-2, in the front line of innate immune defence. Moreover, HBD-2 may be involved in the pathogenesis of H pylori-associated gastritis, possibly through its function as immune and inflammatory mediator.
Isomoto
Hajime
H
Second Department of Internal Medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. hajimei2002@yahoo.co.jp
Mukae
Hiroshi
H
Ishimoto
Hiroshi
H
Nishi
Yoshito
Y
Wen
Chun-Yang
CY
Wada
Akihiro
A
Ohnita
Ken
K
Hirayama
Toshiya
T
Nakazato
Masamitsu
M
Kohno
Shigeru
S
D000890:Anti-Infective Agents / Q000032:analysis; D005750:Gastric Juice / Q000737:chemistry*; D016481:Helicobacter Infections / Q000378:metabolism* / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D023083:beta-Defensins / Q000097:blood / Q000378:metabolism*
D000890:Anti-Infective Agents; C406407:DEFB1 protein, human; C106641:DEFB4A protein, human; D023083:beta-Defensins