Antrum- and corpus mucosa-infiltrating CD4(+) lymphocytes in Helicobacter pylori gastritis display a Th1 phenotype

Abstract

In this study, cytokine patterns produced by CD4(+) T cells isolated from antrum or corpus gastral biopsy specimens of 10 patients with Helicobacter pylori-positive gastritis were compared. To this end, expression of intracellular cytokines (interleukin-4 [IL-4] and gamma interferon) and of CD4 was assessed by flow cytometry. Ten to 60% of the isolated CD4(+) T cells produced gamma interferon upon stimulation. With the exception of one patient, IL-4-positive CD4(+) cells were not detected. Therefore, CD4(+) cells infiltrating antrum and corpus stomach mucosa during H. pylori infection show a Th1 phenotype. This polarized Th1-type response may contribute to the inability of the immune system to eradicate H. pylori infection.

FIG. 1

Relative numbers of CD4⁺ T cells present in gastral biopsy specimens of H. pylori-infected patients and uninfected control patients. T cells were isolated from gastral biopsy specimens as described in the text and processed for intracellular staining of cytokines and CD4. Thereafter, the cells were resuspended in PBS and analyzed by FACS. The figure shows mean numbers of antrum and corpus CD4⁺ T cells present in 100 μl of PBS, as measured by FACS. H.p., H. pylori.

FIG. 2

IFN-γ production by T cells isolated from the stomach of a patient with H. pylori-positive gastritis. T cells were isolated from the antrum (A and C) and corpus (B and D) regions. The T cells were stimulated, and intracellular staining of CD4, IFN-γ, and IL-4 was performed as described in the text. (A and B) Staining with control Abs, which were isotype matched to the anticytokine Abs: y axes, FITC-conjugated mouse IgG1 isotype control Ab; x axes, PE-conjugated rat IgG1-PE isotype control Ab. (C and D) Staining with CyChrome-conjugated anti-CD4 Ab (x axes) and FITC-conjugated anti-IFN-γ Ab (y axes).

FIG. 3

IFN-γ and IL-4 production by peripheral T cells. Peripheral blood mononuclear cells were isolated from heparinized blood of a healthy donor by using a Ficoll-Hypaque density gradient. The cells were cultured in Click’s medium for two weeks in the presence of recombinant human IL-2 (10 U/ml) and recombinant human IL-4 (20 U/ml). Thereafter, the cells were left untreated (left) or stimulated (right), and intracellular staining of CD4, IFN-γ, and IL-4 was performed as described in the text. Gating was restricted to CD4⁺ cells according to staining with anti-CD4 CyChrome. x axes, staining with FITC-conjugated anti-IFN-γ Ab; y axes, staining with PE-conjugated anti-IL-4 Ab.