Antigen-specific lymphocyte proliferation as a marker of immune response in guinea pigs with sustained Helicobacter pylori infection.

Abstract

Helicobacter pylori (H. pylori) bacteria are human pathogens causing symptomatic gastritis, peptic ulcer or gastric cancer. Little is known about the kinetics of immune responses in H. pylori infected patients because the initial moment of infection has not been identified. Various animal models are used to investigate the immune processes related to H. pylori infection. In this study we checked whether H. pylori infection in guinea pigs, mimicking natural H. pylori infection in humans, resulted in the development of specific immune responses to H. pylori antigens by measuring the proliferation of lymphocytes localized in mesenteric lymph nodes, spleen and peripheral blood. The maturity of macrophages and cytokines, delivered by monocyte-macrophage lineage or lymphocytes, were considered as mediators, which might influence the lymphocyte blastogenic response. The obtained results showed the activation of T cells localized in mesenteric lymph nodes by H. pylori antigens in H. pylori infected guinea pigs four weeks postinfection. The blastogenic activity of lymphocytes was shaped by their interaction with antigen presenting cells, which were present in the cell cultures during the whole culture period. Moreover, the balance between cytokines derived from adherent leukocytes including interleukin 8--IL-8 as well as interferon gamma--IFN-γ, and transforming growth factor beta--TGF-β delivered by lymphocytes, was probably important for the successful proliferation of lymphocytes. The H. pylori specific lymphocytes were not propagated in peripheral blood and spleen of H. pylori infected animals. The modulation of immunocompetent cells by H. pylori antigens or their different distribution cannot be excluded.

Impact ofHelicobacter pylorion the healing process of the gastric barrier

“…The antigen concentrations were adjusted experimentally or adopted from previously performed experiments[44,47,48,68]. …”

Immunoregulation of antigen presenting and secretory functions of monocytic cells by Helicobacter pylori antigens in relation to impairment of lymphocyte expansion

“…Guinea pigs are a convenient model for studying the development of specific adaptive immune response to H. pylori antigens. In our previous study we showed that lymphocytes isolated from mesenteric lymph nodes, particularly CD4 + , but not lymphocytes obtained from peripheral blood responded by proliferation to H. pylori antigens included in GE (Miszczyk et al, 2014). D'elios et al, showed that in humans with H. pylori related chronic gastritis or MALT lymphoma, CD4 + T-cell clones, but not CD8 + , proliferated to H. pylori antigens (D'elios et al, 1999).…”

“…Other than in the spleen may also be a location of sensitized lymphocytes capable of clonal expansion in response to H. pylori antigens. Previously it was shown that lymphocytes of guinea pigs infected with H. pylori, which proliferated in the milieu of GE antigens were deposited in the mesenteric lymph nodes (Miszczyk et al, 2014). Another study showed that antigen-specific lymphocytes from the patients infected with H. pylori were accumulated in the basal membrane of the gastric mucosa (Quiding-Jarbrink et al, 2001).…”

“…The H. acynonychis UreA subunit was amplified by a polymerase chain reaction (PCR) as previously described (Hinc et al, 2010), and used as a homologue of H. pylori UreA protein at the concentration of 5 µg/ml. The antigen concentrations were adjusted experimentally (UreA) or adopted from previously performed experiments (Miszczyk et al, 2014). The LPS from the reference strain of H. pylori CCUG 17874 (courtesy of AP.…”

“…Assessment of the H. pylori status. The H. pylori infection in guinea pigs was confirmed by the detection of Helicobacter-like organisms (HLO) in thin layer sections of the stomach tissue, which were stained by routine histological procedure with the Giemsa stain solution and analysed according to the Sydney scale using a light microscope and immunofluorescence staining of mucus smears with rabbit anti-H. pylori antibodies conjugated with fluorescein isothiocyanate (FITC) as previously described (Miszczyk et al, 2014). The cell imaging was performed using a JuLI Smart fluorescent cell analyzer (Digital Biotechnology, Boston, USA).…”