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.

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).

Reduction of naive CD4/CD45RA+ T cells in children with biliary atresia before and after liver transplantation

The aim of this study was to examine whether liver transplantation reverses the abnormal distribution of lymphocyte subsets previously observed in biliary atresia children, namely a selective decrease in the naive CD4/CD45RA+ T cell subset and an increase in the B and natural killer cell subpopulations. Eight biliary atresia children aged 1.08 to 6 years were studied before and 1 year after LTx for comparison with 15 age-matched healthy controls. The posttransplant immunosuppressive regimens included prednisone [0.1 mg/kg] and tacrolimus (level range: a 10-12 microg/dL). The percentage, absolute cell number, and receptor density were assessed by the use of double color flow cytometry (EPICS-XL MCL fluorocytometer). Biliary atresia patients were compared after LTx with subjects before LTx, essentially showing no statistically significant changes in lymphocyte subsets. We conclude that LTx of biliary atresia children does not reverse the abnormal lymphocyte subset distribution present before transplantation. Hence, these changes may reflect either their independence from the liver status or may result from immunosuppressive treatment that contributes to defective CD4+ T cell regeneration reflected by a deficiency in CD4/CD45RA+ naive T cells.

Reduction of CD45RA isoform expression and decrease in CD4 and CD8 receptor density in lymphocytes of patients with primary biliary cirrhosis

BACKGROUND

The immunological background of primary biliary cirrhosis (PBC) remains largely obscure.

METHODS

Using double colour flow cytometry, we estimated the distribution of functionally different lymphocyte subpopulations in the peripheral blood of 25 PBC patients and 18 controls. We examined: 1) the expression of CD3, CD4, CD8, CD19 and CD56 surface receptors, 2) the distribution of lymphocyte subsets bearing 'naive' (CD45RA+) and 'memory' (CD45RO+) phenotypes in both CD4+ and CD8+ cell populations, 3) the expression of an early activation marker (CD69), 4) the distribution of C1.7 mAb binding cytotoxic effectors in CD3+, CD8+ and CD56+ cells. The surface marker expression was evaluated in terms of percentage of positive cells and receptor density.

RESULTS

We found: 1) a decrease in the percentage of total CD3+ and CD4+ cells, an unchanged proportion of CD8+ cells but elevated proportion of CD19+ cells and NK lymphocytes; 2) a reduction in the percentage of 'naive' CD4+ but normal proportion of 'naive' CD8+ as well as CD4+ and CD8+ 'memory' cell subsets; 3) a decrease in the density of CD4 and CD8 receptors in the subsets of 'naive' and 'memory' T cells, 4) an increase in the percentage of CD69 receptor bearing T cells but unchanged proportion of C1.7 mAb.

CONCLUSIONS

It is concluded that the reduction in number of 'suppressor-inducer-like 'naive' CD4+ T-cell subsets in association with the decrease in fluorescence intensity for CD4 and CD8 may significantly contribute to the mechanisms that could account for a development of PBC.

IGF-I triple helix gene therapy of rat and human gliomas

PURPOSE

IGF-I anti-gene technology was applied in treatment of rat and human gliomas using IGF-I triple helix approach.

MATERIAL AND METHODS

CNS-1 rat glioma cell and primary human glioblastoma cell lines established from surgically removed glioblastomas multiforme were transfected in vitro with IGF-I antisense (pMT-Anti-IGF-I) or IGF-I triple helix (pMT-AG-TH) expression vectors. The transfected cells were examined for immunogenicity (immunocytochemistry and flow cytometry analysis) and apoptosis phenomena (electron microscopy). 3 x 10(6) transfected cells were inoculated subcutaneously either into transgenic Lewis rats or in patients with glioblastoma. The peripheral blood lymphocytes (PBL) derived from "vaccinated" patients were immunophenotyped for the set of CD antigens (CD4, CD8 etc).

RESULTS

Using immunocytochemistry and Northern blot techniques, the transfected "antisense" and "triple-helix" cells showed total inhibition of IGF. Transfected cultures were positively stained either for both MHC-I and B7 antigens--60% of cloned lines, or for MHC-I only--40% of cloned lines. Moreover "triple helix" cells as compared to "antisense" cells showed slightly higher expression of MHC-I or B7. Transfected cells also showed the feature of apoptosis in 60%-70% of cells. In in vivo experiments with rats bearing tumors, the injection of "triple helix" cells expressing both MHC-I and B7 interrupted tumor growth in 80% of cases. In contrast, transfected cells expressing only MHC-I stopped development in 30% of tumors. In five patients with surgically resected glioblastoma who were inoculated with "triple helix" cells, PBL showed an increased percentage of CD4 + CD25+ and CD8 + CD11b-cells, following two vaccinations.

CONCLUSIONS

The anti-tumor effectiveness of IGF-I anti-gene technology may be related to both MHC-I and B7 expression in cells used for therapy. The IGF-I antigene therapy of human glioblastoma multiforme increases immune response of treated patients.

Effect of Pseudomonas aeruginosa exotoxin A on CD3-induced human T-cell activation

The effect of Pseudomonas aeruginosa (PA) exotoxin A (P-ExA) on CD3-induced T-cell activation was studied on the level of T-cells (proliferation, synthesis of interleukin (IL)-2, expression of IL-2R complex, ICAM-1,2 and LFA-1 molecules), and on the level of monocytes (expression of ICAM-1,2, LFA-1 molecules, as well as FcRI and CD14 receptors). We found that: (1) P-ExA blocked T-cell proliferation and this effect was totally reversed by intact monocytes, and partially by IL-2 or TPA but not by costimulatory cytokines (IL-1alpha, IL-1beta, TNF-alpha or IL-6); (2) P-ExA transiently, in short-term cultures (48 h), inhibited synthesis of IL-2; (3) prolonged stimulation (96 h) of peripheral blood mononuclear cells (PBMC) or CD4 + T-cells with P-ExA in high or low doses (100 and 10 ng/ml, respectively), enhanced the level of IL-2 in the cultures; (4) P-ExA at low dose, combined with IL-1beta, TNF-alpha or IL-6, up-regulated synthesis of IL-2; and (5) stimulation of T-cells with anti-CD3 monoclonal antibody (mAb) and P-ExA at high dose diminished the expression of the p55 chain but not of the p75 chain of IL-2R complex and slightly affected the expression of CD3 complex, ICAM-1,2 and LFA-1 molecules. Hence, P-ExA can regulate the level of IL-2 in cultures of CD3-induced T-cells either by inhibition of IL-2 consumption (when P-ExA is applied in high dose), or by induction of IL-2 production (a costimulatory effect exerted by P-ExA in low dose in combination with monokines). Action of P-ExA on monocytes resulted in: (1) inhibition of the expression of ICAM-1,2 molecules and their ligand LFA-1 molecule; (2) low expression of FcRI receptor (a ligand for Fc part of CD3 mAb); and (3) inhibition (over 90%) of the expression of CD14 molecule. In conclusion, P-ExA-induced anergy of T-cells depends on: (a) decrease in the affinity of IL-2R complex on activated T-cells; and (b) inhibition of the accessory activities of monocytes.

Linkage studies exclude the AT-V gene(s) from the translocation breakpoints in an AT-V patient

An 8-year-old girl with severe microcephaly of prenatal onset, borderline intelligence, defects of skin pigmentation, deficiency of both humoral and cellular immunity, a normal serum alpha-fetoprotein level and hypersensitivity to ionizing irradiation is described. Spontaneous chromosomal breakage in lymphocytes together with the clinical presentation led to the diagnosis of ataxia telangiectasia variant (AT-V). In addition, the patient carried a constitutional translocation of paternal origin: 46,XX,t(3;7)(q12;q31.3) pat. In subsequent linkage and haplotype studies in 12 AT-V families with microsatellite markers from each of the translocation breakpoint regions, we could clearly exclude the localization of an AT-V gene to these regions.

Primary immunodeficiency diseases in children treated in the Children's Memorial Hospital, Poland

One hundred and three cases of primary immunodeficiency diseases were diagnosed among children suffering mainly from chronic and severe infections in the period 1980-1987. Predominantly antibody defects were recognized in 48 patients (46.6%), combined immunodeficiencies in 36 patients (35%), phagocytic disorders in 12 patients (11.6%), complement defects in 6 patients (5.8%), and cell-mediated disease (Di George syndrome) in 1 patient. Allergic complications were observed in 25 patients (24.2%) and malignancy-in 3 patients (2.9%). More detailed immunological studies were performed in children with X-linked agammaglobulinemia in the course of intravenous immunoglobulin therapy and in children with ataxia telangiectasia.