Immunomodulatory effects of Lactobacillous plantarum and Helicobacter pylori CagA⁺ on the expression of selected superficial molecules on monocyte and lymphocyte and the synthesis of cytokines in whole blood culture.

Helicobacter pylori (H. pylori) infections are usually superficial and clinically asymptomatic, but in approximately 10-20% cases it can be more aggressive and associated with other pathologies. The reason for weak or strong pro-inflammatory responses in gastric mucosa that occur during H. pylori infection is not understood. Combined treatment, including antibiotic therapy with administration of probiotic bacteria along, considerably improves the effectiveness of H. pylori eradication and reduces the relapse rate. Thus, the aim of this study was to analyze the effect of Lactobacillus plantarum (L. plantarum) and/or H. pylori CagA(+) on leucocytes in whole blood cultures. This study revealed how selected strains of H. pylori and L. plantarum modulate expression of chosen membrane markers of monocytes and lymphocytes, and the cytokine synthesis of in vitro cultures. The level of IFN-γ was higher in cultures stimulated with L. plantarum than in combination of this two examinated strains. We also observe the tendency to increase the level of IFN-γ by L. planatrum in relation to cells stimulated by H. pylori. In contrast, both H. pylori alone and in combination with L. plantarum had a strong modulatory effect on the synthesis of interleukin-10. Moreover lymphocytes with higher expression of CD25 and CD58 receptors was observed only in those cultures that were stimulated with L. plantarum strain alone or in combination with H. pylori. Effects exerted on the immune system, both in terms of natural and adaptive response, constitute the only functional criterion of probiotic bacteria. The immunostimulant effects documented in this study suggest that Lactobacillus spp. can restore immune function of mucosal membrane during symptomatic infection with H. pylori.

Hyperthermia-induced reorganization of microtubules and microfilaments and cell killing in CHO AA8 cell line.

The aim of this study was to elucidate the effects of hyperthermic treatment on cell morphology and the cytoskeleton in CHO AA8 cell line. The effects of exposure to elevated temperature were analyzed in CHO AA8 cell line by fluorescence microscopy and flow cytometry. The 30 min, at 44.5 degrees C heat shock treatment resulted in the collapse of microtubules (MTs) and microfilaments (MFs) around the nucleus followed by their recovery 24 h after heating. The initial collapse of these cytoskeletal systems, observed 15 min after treatment, was accompanied by the appearance of cells with reduction of volume, shrunken cytoplasm and condensed chromatin. 24 h afterwards, there was the increase in the number of cells with restored and extended MT and MF cytoskeletons. Most of them were larger in size compared to the control cells and had multiple nuclei. 48 h after heat shock the highest number of the giant cells with alternation in nuclear morphology was seen. Flow cytometry analysis revealed the increase in the number of cells with externalized phosphatidylserine 24 h and 48 h after hyperthermic treatment. These results suggest that following heat shock, CHO AA8 cells undergo mitotic catastrophe that presumably represents one of the events resulting in apoptosis.

Combined effect of different lactic acid bacteria strains on the mode of cytokines pattern expression in human peripheral blood mononuclear cells.

The balance between immunogenic and tolerogenic activities in human immune system strongly depends on microflora-induced pro-and anti-inflammatory activities. Lactic acid bacteria (LAB) are important components of microflora. The interactions of the different strains of LAB and the cells of immune system are largely unknown. To assess if LAB strains composition would have an effect on the cellular responses profile (proliferation, cytokines synthesis) peripheral blood mononuclear cells (PBMC) model system was used. PBMC were induced by three different strains of LAB: Lactobacillus acidophilus, Lactobacillus delbrueckii spp. bulgaricus, Bifidobacterium bifidum. Tested strains were mixed together, in combinations with each other (pairs) or alone. Both, the LAB mixture as well as the pairs and the single LAB strains induced low lymphocyte proliferation (about 10% of ConA-induced response). However, the single LAB strains and their combinations were quite different cytokines inducers. First, L. acidophilus was much stronger IFN-gamma inducer than the LAB mixture, being a few times higher IL-12 stimulator than L. bulgaricus and B. bifidum. Second, L. bulgaricus and B. bifidum suppressed L.acidophilus-induced IFN-gamma synthesis to the level equal to that induced by the LAB mixture, limiting IL-12 production by about 30% and 70%, respectively. Third, the LAB strains were good IL-10 and TNF-alpha inducers, irrespectively of their combinations used. We conclude that LAB strains' pro or anti-inflammatory potentials are at least in part dependent on their composition. Low LAB mixture-induced IL-12 and IFN-gamma production and relatively high IL-10 and TNF-alpha expression may represent cellular activities normally induced in vivo by a combined action of bacterial antigens. Their presence is important to limit pro-inflammatory reactions (via IL-10) and to provide protection against infections (via TNF-alpha).