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. 2013 Jul 30;47(3):258-65.
doi: 10.2478/raon-2013-0043. eCollection 2013.

Inhibition of cathepsin X enzyme influences the immune response of THP-1 cells and dendritic cells infected with Helicobacter pylori

Miha Skvarc  1 , David Stubljar, Andreja Natasa Kopitar, Samo Jeverica, Bojan Tepes, Janko Kos, Alojz Ihan
Affiliations

Inhibition of cathepsin X enzyme influences the immune response of THP-1 cells and dendritic cells infected with Helicobacter pylori

Miha Skvarc et al. Radiol Oncol. .

Abstract

Background: The immune response to Helicobacter pylori importantly determines the outcome of infection as well as the success of eradication therapy. We demonstrate the role of a cysteine protease cathepsin X in the immune response to H. pylori infection.

Materials and methods: We analysed how the inhibition of cathepsin X influenced the immune response in experiments when THP-1 cells or dendritic cells isolated from patients were stimulated with 48 strains of H. pylori isolated from gastric biopsy samples of patients which had problems with the eradication of bacteria.

Results: The experiments, performed with the help of a flow cytometer, showed that the expression of Toll-like receptors (TLRs), especially TLR-4 molecules, on the membranes of THP-1 cells or dendritic cells was higher when we stimulated cells with H. pylori together with inhibitor of cathepsin X 2F12 compared to THP-1 cells or dendritic cells stimulated with H. pylori only, and also in comparison with negative control samples. We also demonstrated that when we inhibited the action of cathepsin X in THP-1 cells, the concentrations of pro-inflammatory cytokines were lower than when THP-1 cell were stimulated with H. pylori only.

Conclusions: We demonstrated that inhibition of cathepsin X influences the internalization of TLR-2 and TLR-4. TLR-2 and TLR-4 redistribution to intra-cytoplasmic compartments is hampered if cathepsin X is blocked. The beginning of a successful immune response against H. pylori in the case of inhibition of cathepsin X is delayed.

Keywords: cathepsin X; cytokines; dendritic cells; hampered immune response; macrophages; toll-like receptors.

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Figures

FIGURE 1.
FIGURE 1.
Expression of TLR-4 on THP-1 cells after stimulation with H. pylori or with H. pylori plus inhibitor of cathepsin X. 1–20 strains of H. pylori sensitive to clarithromycin, 21–40 strains of H. pylori resistant to clarithromycin, CTX inhibitor of cathepsin X.
FIGURE 2.
FIGURE 2.
Concentrations of cytokines (pg/ml) IL-6, IL-1b, IL-8, IL-10 in the supernatant of THP-1 cells after stimulation with H. pylori strains or with H. pylori strains plus inhibitor of cathepsin X (CTX). 1–20 strains of H. pylori sensitive to clarithromycin, 21–40 strains of H. pylori resistant to clarithromycin.
FIGURE 3.
FIGURE 3.
The expression of TLR-2 and TLR-4 on DCs (MFI - mean fluorescence intensity) in box plot. NEG negative control – un-stimulated DCs, INH DCs with H. pylori plus 2F12 - inhibition, STIM DCs with H. pylori - stimulation.
See this image and copyright information in PMC

References

    1. Rad R, Ballhorn W, Voland P, Eisenächer K, Mages J, Rad L, et al. Extracellular and intracellular pattern recognition receptors cooperate in the recognition of Helicobacter pylori. Gastroenterology. 2009;136:2247–57. - PubMed
    1. Amieva MR, El-Omar EM. Host-bacterial interactions in Helicobacter pylori infection. Gastroenterology. 2008;134:306–23. - PubMed
    1. Borody T, Ren Z, Pang G, Clancy R. Impaired host immunity contributes to Helicobacter pylori eradication failure. Am J Gastroenterol. 2002;97:3032–7. - PubMed
    1. Mitchell P, Germain C, Fiori PL, Khamri W, Foster GR, Ghosh S, et al. Chronic exposure to Helicobacter pylori impairs dendritic cell function and inhibits Th1 development. Infect Immun. 2007;75:810–7. - PMC - PubMed
    1. Bühling F, Peitz U, Krüger S, Küster D, Vieth M, Gebert I, et al. Cathepsins K, L, B, X and W are differentially expressed in normal and chronically inflamed gastric mucosa. Biol Chem. 2004;385:439–45. - PubMed

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