Gastroenterology

Gastroenterology

Volume 125, Issue 6, December 2003, Pages 1613-1625
Gastroenterology

Clinlcal-alimentary tract
Expression of LL-37 by human gastric epithelial cells as a potential host defense mechanism against Helicobacter pylori

https://doi.org/10.1053/j.gastro.2003.08.028Get rights and content

Abstract

Background & Aims: LL-37/human cationic antimicrobial peptide 18 (hCAP18) is a human cathelicidin with broad-spectrum antimicrobial, lipopolysaccharide binding, and chemotactic activities. This study examined the role of LL-37/hCAP18 in gastric innate immune defense by characterizing its constitutive and regulated expression by human gastric mucosa and its bactericidal activity against the gastric pathogen Helicobacter pylori.

Methods: LL-37/hCAP18 messenger RNA expression in normal and H. pylori-infected gastric mucosa and gastric epithelial cells was determined by in situ hybridization, real-time polymerase chain reaction, immunostaining, and immunoblot analysis. Bactericidal activity was measured by using a colony-forming unit assay.

Results: LL-37/hCAP18 messenger RNA and protein were expressed in a distinct distribution by surface epithelial cells as well as chief and parietal cells in the fundic glands of normal gastric mucosa. LL-37/hCAP18 was significantly increased in the epithelium and gastric secretions of H. pylori-infected patients, but not in individuals with non-H. pylori-induced gastric inflammation. Infection of cultured gastric epithelial cells with a wild-type but not an isogenic ΔcagE mutant strain of H. pylori increased LL-37/hCAP18 expression, indicating that H. pylori-induced regulation of LL-37/hCAP18 production required an intact type IV secretion system. LL-37, the C-terminal peptide of LL-37/hCAP18, alone or in synergy with human β-defensin 1, was bactericidal for several H. pylori strains.

Conclusions: These data indicate that H. pylori up-regulates production of LL-37/hCAP18 by gastric epithelium and suggest this cathelicidin contributes to determining the balance between host mucosal defense and H. pylori survival mechanisms that govern chronic infection with this gastric pathogen.

Section snippets

Antibodies, cytokines, and antimicrobial peptides

Preimmune chicken IgY, chicken IgY anti-LL-37 that recognizes the LL-37 peptide domain, and chicken IgY anti-hCAP18 antibody that recognizes the cathelin domain were as described earlier.39 Rabbit IgG anti-LL-37 antibody was a gift of B. Agerberth. Rabbit anti-H+, K+-ATPase (α-subunit) was from Calbiochem (San Diego, CA). Control rabbit serum and IgG were from Jackson ImmunoResearch Laboratories (West Grove, PA). Synthetic LL-37 peptide was from SynPep Corp. (Dublin, CA).40 Synthetic hBD-1 and

LL-37/hCAP18 mRNA and protein expression by normal human gastric epithelium

To determine if LL-37/hCAP18 was expressed by human gastric epithelium in vivo, mucosal biopsies of normal human antrum were analyzed for LL-37/hCAP18 mRNA expression by in situ hybridization. LL-37/hCAP18 mRNA was expressed by the luminal surface and adjacent gastric pit epithelium and by epithelium in the deeper gastric glands (Figure 1A and C). Similar results were obtained using gastric tissues from 3 additional individuals using probes directed to either the LL-37 or cathelin domains

Discussion

Gastric epithelial cells express LL-37/hCAP18 mRNA and protein and release this cathelicidin into gastric secretions. LL-37/hCAP18 was produced by those epithelial cells that line the luminal surface and upper gastric pits and by cells deeper in gastric glands but was absent from cells in the regenerative mucus neck zone. In addition, there was little, if any, LL-37/hCAP18 expression in regions of increased epithelial cell proliferation in hyperplastic polyps, by the surface epithelium in

Acknowledgements

We thank John Leopard and Jennifer Smith for technical assistance and Dr. Nissi Varki for pathological consultation.

References (67)

  • J Johansson et al.

    Conformation-dependent antibacterial activity of the naturally occurring human peptide LL-37

    J Biol Chem

    (1998)
  • D.J Schibli et al.

    The solution structures of the human beta-defensins lead to a better understanding of the potent bactericidal activity of HBD3 against Staphylococcus aureus

    J Biol Chem

    (2002)
  • J.M Schroder

    Epithelial peptide antibiotics

    Biochem Pharmacol

    (1999)
  • J.E Everhart

    Recent developments in the epidemiology of Helicobacter pylori

    Gastroenterol Clin North Am

    (2000)
  • H.P Wirth et al.

    Helicobacter pylori Lewis expression is related to the host Lewis phenotype

    Gastroenterology

    (1997)
  • A Peschel

    How do bacteria resist human antimicrobial peptides?

    Trends Microbiol

    (2002)
  • D.A O’Neil et al.

    Regulation of human β-defensins by gastric epithelial cells in response to infection with Helicobacter pylori or stimulation with interleukin-1

    Infect Immun

    (2000)
  • Y Hamanaka et al.

    Expression of human beta-defensin 2 (hBD-2) in Helicobacter pylori induced gastritisantibacterial effect of hBD-2 against Helicobacter pylori

    Gut

    (2001)
  • D Santini et al.

    Lysozyme localization in normal and diseased human gastric and colonic mucosaA correlative histochemical, immunohistochemical and immunoelectron microscopic investigation

    Apmis

    (1992)
  • R Bals

    Epithelial antimicrobial peptides in host defense against infection

    Respir Res

    (2000)
  • H.G Boman

    Innate immunity and the normal microflora

    Immunol Rev

    (2000)
  • T Ganz

    Defensins and host defense

    Science

    (1999)
  • D.A O’Neil et al.

    Expression and regulation of the human β-defensins hBD-1 and hBD-2 in intestinal epithelium

    J Immunol

    (1999)
  • N Uehara et al.

    Human beta-defensin-2 induction in Helicobacter pylori-infected gastric mucosal tissuesantimicrobial effect of overexpression

    J Med Microbiol

    (2003)
  • R Gennaro et al.

    Structural features and biological activities of the cathelicidin-derived antimicrobial peptides

    Biopolymers

    (2000)
  • R.I Lehrer et al.

    Cathelicidinsa family of endogenous antimicrobial peptides

    Curr Opin Hematol

    (2002)
  • M Zaiou et al.

    Cathelicidins, essential gene-encoded mammalian antibiotics

    J Mol Med

    (2002)
  • K Hase et al.

    Cell differentiation is a key determinant of cathelicidin LL-37/human cationic antimicrobial protein 18 expression by human colon epithelium

    Infect Immun

    (2002)
  • R Bals et al.

    The peptide antibiotic LL-37/hCAP-18 is expressed in epithelia of the human lung where it has broad antimicrobial activity at the airway surface

    Proc Natl Acad Sci U S A

    (1998)
  • S.M Travis et al.

    Bactericidal activity of mammalian cathelicidin-derived peptides

    Infect Immunol

    (2000)
  • T Kirikae et al.

    Protective effects of a human 18-kilodalton cationic antimicrobial protein (CAP18)-derived peptide against murine endotoxemia

    Infect Immun

    (1998)
  • J Turner et al.

    Activities of LL-37, a cathelin-associated antimicrobial peptide of human neutrophils

    Antimicrob Agents Chemother

    (1998)
  • F Niyonsaba et al.

    Evaluation of the effects of peptide antibiotics human beta-defensins- 1/-2 and LL-37 on histamine release and prostaglandin D(2) production from mast cells

    Eur J Immunol

    (2001)
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    Supported by NIH grants DK58960 and DK35108 (to M.F.K.), DK53649 (to S.P.C.), AI052453 (to R.L.G.), and a VA Merit Award (to R.L.G.).

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