Suppression of human mononuclear cell response by Helicobacter pylori: Effects on isolated monocytes and lymphocytes

• Published in: FEMS immunology and medical microbiology Vol. 8; no. 2; pp. 157 - 166
• Main Authors: Knipp, U., Birkholz, S., Kaup, W., Mahnke, K., Opferkuch, W.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-02-1994; Blackwell
• Subjects: Antigens, CD - biosynthesis; Antigens, Surface - biosynthesis; B-Lymphocytes - immunology; Bacteriology; Biological and medical sciences; Cell Adhesion Molecules - biosynthesis; Cell Transformation, Viral; Cytoplasm - immunology; Fundamental and applied biological sciences. Psychology; Helicobacter pylori; Helicobacter pylori - immunology; HLA-DR Antigens - biosynthesis; Humans; Immune Tolerance - immunology; Immunosuppression; In Vitro Techniques; Intercellular Adhesion Molecule-1; Lymphocyte Activation - drug effects; Microbiology; Monocytes - immunology; Mononuclear cell; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phytohemagglutinins - pharmacology; Subcellular Fractions - immunology; Suppressive activity; T-Lymphocytes - immunology; Tetradecanoylphorbol Acetate - pharmacology; Human; Immunosuppression; Mononuclear cell; Immune response; Spirillales; Helicobacter pylori; Spirillaceae; Bacteria; Host agent relation; Cellular immunity; Defense; Mechanism
• ISSN: 0928-8244; 1574-695X
• DOI: 10.1111/j.1574-695X.1994.tb00438.x

Helicobacter pylori colonization of the human gastric mucosa causes a long‐term, not self‐limiting inflammation, suggesting that the microbe has properties to protect itself against the host immune defence system. Recently we were able to demonstrate that H. pylori suppresses the in vitro proliferative response of human peripheral blood mononuclear cells to antigens as well as to mitogens without affecting cell viability. The purpose of this study was to clarify which cell subsets of mononuclear cells are influenced by H. pylori. The use of monocytes which had been pretreated with a soluble cytoplasmic fraction of H. pylori (30 μg ml−1) led to a suppressed proliferation of T cells after PHA‐activation. Activation of isolated T cells with PHA and PMA revealed that the proliferative response of lymphocytes could also be inhibited independently of monocytes. The anti‐proliferative effect was associated with a reduction of IL‐2 receptor (CD25) expression as well as an inhibition of blastogenesis. Furthermore, the spontaneous proliferation of EBV‐transformed B cell lines was suppressed in a dose‐dependent manner. FACS‐analysis of HLA‐DR, ICAM‐1 and CD14 expression on the surface of monocytes revealed an influence of H. pylori on CD14 expression at a concentration of 30 μg ml−1, while the expression of HLA‐DR and ICAM‐1 was not affected at this concentration.