Study of the protective effect of calcium channel blockers against neuronal damage induced by glutamate in cultured hippocampal neurons.

BACKGROUND: The aim of this study was to examine the putative protective effect of calcium channel blockers on hippocampal neurons in the experimental model of excitotoxic damage. METHODS: Seven-day old primary dissociated cultures of rat hippocampal neural cells containing one of the following calcium channel blockers: cinnarizine, flunarizine or nimodipine were exposed to glutamate-induced injury. Quantitative assessments of neuronal injury were accomplished by measuring lactate dehydrogenase (LDH) activity in the media 24 h after exposure to glutamate and by counting and establishing the apoptotic and necrotic cells in flow cytometry with Annexin V-FITC/PI staining. RESULTS: In our experiment, glutamate induced a 339% elevation of apoptotic cells and a 289% increase of necrotic cells in hippocampal neurons as compared to control cultures without drugs. In cultures containing flunarizine, glutamate-induced cell apoptosis was suppressed by 62% while necrosis showed no significant alternation. Cinnarizine exerted no anti-apoptotic effects on glutamate-injured cultured hippocampal neurons, while nimodipine intensified the apoptotic pathway of cell death and promoted an increase in the number of apoptotic neurons by 26%. When cinnarizine or nimodipine were used, the percentage of necrotic cells was significantly lower when compared with glutamate-injured cultures and it amounted to 44% and 24% for cinnarizine and nimodipine, respectively. CONCLUSIONS: The obtained results suggest the beneficial anti-apoptotic potential of flunarizine and the anti-necrotic potential of cinnarizine against glutamate-induced death of cultured hippocampal neurons. Nimodipine can protect neurons against necrosis, but has an intensified adverse pro-apoptotic effect on cultured neurons in the experimental model of excitotoxic injury.

Production of cytokines by mononuclear cells of hypertrophic adenoids in children with otitis media with effusion.

Hypertrophic adenoids with otitis media with effusion is a common infectious disease and present a serious otological problem in children. Cytokines, potent inflammatory mediators, play important role in the initiation of immunological response in otitis media. Adenoids excised due to hypertrophy with or without chronic otitis media with effusion were used to isolate mononuclear cells. Secretion of cytokines by non-stimulated and PHA-stimulated cells was determined by specific ELISAs. We found a significant increase in the production of IL-5 and TNF-α secreted by adenoidal cells of children with otitis media with effusion compared to group with hypertrophic adenoids. No differences were found in the secretion of IL-8, IL-6, and IL-10 between these two groups of patients. Our results suggest a difference between the immunological responses in the course of hypertrophic adenoids with otitis media as compared to hypertrophic adenoids.

Generation of functional T-regulatory cells in children with metabolic syndrome.

Recent research implies a role of decreased number and/or function of T-regulatory cells (Tregs) in low-grade inflammation associated with obesity and atherosclerosis. The enhancement of atheroprotective immunity by the expansion of Tregs could serve as a therapeutic strategy in obesity-related immunological disturbances. The aim of our study was an attempt to generate Treg cells in children with risk factors for the development of cardiovascular disease and to compare the results to those obtained in healthy subjects. The study group consisted of 30 children with metabolic syndrome (MS) and 30 controls. Conventional CD4(+)CD25(-) cells separated from the peripheral blood were converted into Treg cells with the use of CD3/CD28 antibodies and interleukin (IL)-2/transforming growth factor (TGF)-ß stimulation. The expression of critical Treg molecules and cytokines was assessed at mRNA and protein levels. The percentages of Treg cells in the peripheral blood were significantly lower in the children with MS compared to the healthy subjects. After the culture with CD3/CD28 and IL-2/TGF-ß we detected a significant increase in the expression of Tregs marker transcription factor FoxP3. The Tregs induced from the children with MS varied from the ones obtained in the controls in the expression of some molecules at mRNA level (e.g. IL-27, LGAL, KLF10 and NRP1) yet not in proliferation studies. For the first time, we have demonstrated the possibility of generating functional Treg cells in children with MS. The results of our study could be used in the design of therapeutic interventions in obesity associated immunologic disturbances.

[Generation of T regulatory cells in children with type 1 diabetes mellitus]. / Generacja komórek T regulatorowych u dzieci z cukrzyca typu 1.

INTRODUCTION: In spite of intensive research the pathogenesis of type 1 diabetes mellitus is not thoroughly understood. One of the ideas which currently has a great number of supporters is the theory of the participation of T regulatory cells in the mechanism of insufficient suppression of the immune response against pancreatic self -antigens. According to some authors, the infusion of T regulatory cells in autoimmune diseases could lead to long -term remission or even a complete cure. AIM OF THE STUDY: The aim of our present study was to achieve T regulatory cells from conventional T lymphocytes isolated from a small amount of peripheral blood in children with type 1 diabetes mellitus and their comparison to the Tregs generated from the blood of control children. Additionally, we assessed the changes in the expression of selected genes essential for the function of these cells during Tregs generation. MATERIAL AND METHODS: The examined group consisted of 20 children with type 1 diabetes mellitus, the control group consisted of 20 non -diabetic children. From the peripheral blood CD4+CD25 - cells were separated and cultured with T -reg expander and interleukin (IL) 2. Before and after the culture the cells were analysed according to the expression of transcription factor FoxP3 and other molecules/cytokines: OX40, 4 -1BB, GITR, ICOS -1, CTLA -4 and IFN -γ, IL -10 and TGF -ß. RESULTS: We observed a significantly higher percentage of T regulatory cells after the culture (with no difference between diabetic and control children). Moreover, we observed a lower expression of mRNA for GITR molecule and a higher IL -10 expression in the cultures of diabetic children compared to the control ones. The cells cultured from the blood of control children were characterised by a higher increase in the expression of mRNA for ICOS -1 and a lower expression of mRNA for TGF -ß in comparison to the cultures from diabetic children. CONCLUSIONS: The results of our investigations confirm the possibility of generating T regulatory cells from conventional T lymphocytes from peripheral blood of children with newly recognised type 1 diabetes mellitus.

Levetiracetam protects hippocampal neurons in culture against hypoxia-induced injury.

Many experimental studies indicate that some antiepileptic drugs possess neuroprotective properties in varied models of neuronal injury. Levetiracetam is a second-generation antiepileptic drug with a novel mechanism of action. In the present study, we evaluated the putative neuroprotective effect of levetiracetam on primary hippocampal cultures at seven day in vitro. Cell death was induced by incubation of neural cultures in hypoxic conditions over 24 hours. Neuronal injury was assessed by morphometric investigation of death/total ratio of neurons in light microscopy using Trypan blue staining and by evaluation of lactate dehydrogenase (LDH) release in the culture medium. Our results indicate that pre-conditioning of hippocampal cultures with high concentrations of levetiracetam (100 µM and 300 µM) protects neurons against hypoxia-induced death. Two-fold higher number of neurons remained viable as compared to control cultures without drug. Lack of neuroprotective action of the drug on hippocampal neural cultures was observed, when a low concentration (10 µM) of levetiracetam was used.

Transformation of conventional T cells into regulatory T cells in children with metabolic syndrome.

BACKGROUND: Much research has been done in the recent years to establish an association between obesity, metabolic syndrome and the immune system. Numerous data suggest that the decreased number and/or function of regulatory T cells (Treg cells) can lead to chronic minimal inflammation present in patients with obesity and trigger formation of atherosclerotic plaque. AIM: To generate Treg cells from the peripheral blood in children meeting the diagnostic criteria of metabolic syndrome. METHODS: A total of 25 children with metabolic syndrome and 25 controls were enrolled in the study. Peripheral blood was collected, CD4(+)/CD25(-) cells were separated and cultured for 4 weeks in the presence of a Treg expander (CD3/CD28) and interleukin-2. The expression of the transcription factor FoxP3 as a Treg marker was assessed before and after culture using reverse transcriptase polymerase chain reaction (RT-PCR) and flow cytometry. RESULTS: Before the culture we observed a slightly lower percentage of Treg cells in children with metabolic syndrome vs controls. After the culture we noted a significant increase in mRNA expression and in the percentage of FoxP3-positive cells. We observed no differences in the results between the children with metabolic syndrome and the controls. CONCLUSIONS: Our study shows that it is possible to generate Treg cells from peripheral blood of children with metabolic syndrome. In future, these findings could be used to develop a model of immunotherapeutic intervention for patients at risk of cardiovascular disease.

The mRNA expression of pro- and anti-inflammatory cytokines in T regulatory cells in children with type 1 diabetes.

Type 1 diabetes mellitus (T1DM) is caused by the autoimmune-mediated destruction of insulin-producing beta cells in the pancreas. T regulatory cells (Tregs) represent an active mechanism of suppressing autoreactive T cells that escape central tolerance. The aim of our study was to test the hypothesis that T regulatory cells express pro- and anti-inflammatory cytokines, elements of cytotoxicity and OX40/4-1BB molecules. The examined group consisted of 50 children with T1DM. Fifty two healthy individuals (control group) were enrolled into the study. A flow cytometric analysis of T-cell subpopulations was performed using the following markers: anti-CD3, anti-CD4, anti-CD25, anti-CD127, anti-CD134 and anti-CD137. Concurrently with the flow cytometric assessment of Tregs we separated CD4+CD25+CD127dim/- cells for further mRNA analysis. mRNA levels for transcription factor FoxP3, pro- and anti-inflammatory cytokines (interferon gamma, interleukin-2, interleukin-4, interleukin-10, transforming growth factor beta1 and tumor necrosis factor alpha), activatory molecules (OX40, 4-1BB) and elements of cytotoxicity (granzyme B, perforin 1) were determined by real-time PCR technique. We found no alterations in the frequency of CD4+CD25highCD127low cells between diabetic and control children. Treg cells expressed mRNA for pro- and anti-inflammatory cytokines. Lower OX40 and higher 4-1BB mRNA but not protein levels in Treg cells in diabetic patients compared to the healthy children were noted. Our observations confirm the presence of mRNA for pro- and anti-inflammatory cytokines in CD4+CD25+CD127dim/- cells in the peripheral blood of children with T1DM. Further studies with the goal of developing new strategies to potentiate Treg function in autoimmune diseases are warranted.

[Regulatory T cells in children with acute lymphoblastic leukaemia]. / Limfocyty t regulatorowe u dzieci z ostra bialaczka limfoblastyczna.

UNLABELLED: There is a rising interest in the field of immunotherapy in cancer in the last few years. One of the methods is to prevent the immunosuppression accompanying neoplastic diseases including acute lymphoblastic leukaemia (ALL) in children. In healthy people regulatory T cells (Tregs) prevent the autoimmune, destructive activation of T lymphocytes. However, the hyperfunction of Tregs will lead to impairement of the immune system. THE AIM: of our study was to determine the Tregs (including molecules important for their function) in the peripheral blood of children with ALL. MATERIAL AND METHODS: Thirty children were enrolled into our study, the assessment of Tregs was performed with flow cytometry including the following antigens: CD4, CD10, CD19, CD25, CD28, CD45, CD45RA, CD45RO, CD54 (ICAM-1), CD62L, CD69, CD103, CD127, CD134 (OX40), CD152 (CTLA-4), GITR. RESULTS: 1. The percentages of Tregs were higher in the blood of the examined group, however the difference was not statistically significant; 2. In the examined group higher percentage of Tregs with the coexpression of CD45RA, CD134 and CD152 antigens were noted; 3. The percentages of Tregs with coexpression of CD62L (with or without CD103) and CD54 were lower then in the control group; 4. We did not observe differences in Tregs with coexpression of CD11a, CD27, CD28, CD45RO, CD69, CD103, GITR antigens between the examined and the control group. CONCLUSIONS: The finding of smaller number and lower percentage of regulatory T cells with coexpression of CD62L or lack expression of CD103 in children with ALL as compared to the control group, may be interpreted as activation of Treg cells and one of the mechanisms of immunosuppression in cancer of children. Further studies in this direction are needed.

Diminished expression of ICOS, GITR and CTLA-4 at the mRNA level in T regulatory cells of children with newly diagnosed type 1 diabetes.

Diabetes mellitus is one of the most common chronic diseases in children. T regulatory cells (Tregs) modulate response to autoantigens and probably play a role in pathogenesis of type 1 diabetes (T1DM). The aim of the present study was the assessment of T regulatory cells including their percentages and expression of critical genes in these cells in children with newly diagnosed type 1 diabetes. The examined group consisted of 50 children with T1DM. A flow cytometric analysis of T-cell subpopulations was performed using the following markers: anti-CD4, anti-CD25 and anti-CD127 (=IL-7R). Additionally, T regulatory cells were isolated for assessment of mRNA levels for chosen genes with the real-time RT-PCR technique. The percentages of CD4(+)CD25(high)CD127(dim/-) were very low and did not differ between T1DM and control children. We did not observe any statistically significant differences between healthy and diabetic children in mRNA expression for FoxP3, IL-7R (CD127), IL-8RA, IL-10RA, IL-12A, IL-2RA (CD25), IL-21, STAT1, STAT3, SOCS2, SOCS3, TGF-beta1-R1, TGF-beta-R2 and TBX-21 genes. Interestingly the mRNA level for CTLA-4, ICOS1, IL-23, IL-27, SMAD3 and GITR were lower in Treg cells of children with diabetes compared to the control patients. No disturbances in the percentages of T regulatory cells in patients with diabetes but diminished expression of some elements important in Treg function could be the result of an immunologic imbalance accompanying the onset of the diabetes. The results of our study should be used in future research in the field of immunotherapy in pediatric diabetes.

Profile of exoglycosidases in synovial cell cultures derived from human synovial membrane.

OBJECTIVE: Determining the activity of lysosomal exoglycosidases in tissue cultures of synoviocytes derived from the knee joints of patients with injured anterior cruciate ligaments (ACL), juvenile idiopathic arthritis (JIA), and rheumatoid arthritis (RA). METHODS: The following exoglycosidases in cultured synoviocytes were analyzed with p-nitrophenyl derivatives of appropriate sugars as substrates: hexosaminidase (HEX) and its isoenzyme A (HEX-A), beta-glucuronidase (GluA), beta-galactosidase (GAL), alpha-mannosidase (MAN), and alpha-fucosidase (FUC). RESULTS: In our cell cultures, fibroblast-like synovial cells (FLS) dominated. In the group of patients with ACL-injuries, and in the groups of patients with JIA and RA, the activity of the investigated exoglycosidases was significantly higher in the intra- rather than in the extracellular compartment. Hexosaminidase was the predominant exoglycosidase. Stimulation of synoviocytes by IL-1beta in cell cultures significantly increased the activity of HEX, HEX-A, and GluA in both compartments, as well as of GAL, MAN, and FUC in the intracellular compartment. Stimulation by IL-1beta rheumatoidal synoviocytes increased by 128-201% the activity of HEX and HEX A in intracellular compartments and 33-72% in extracellular compartment. CONCLUSIONS: The profile of lysosomal exoglycosidases in a cell culture of human synoviocytes is similar, but not identical, to those in the knee joint. Hexosaminidase is the dominant glycosidase in cultured unstimulated and IL-1beta-stimulated human synoviocytes. The HEX inhibitors may be new drugs for the treatment of inflamed knee joints.

Upregulation of antigen-processing machinery components at mRNA level in acute lymphoblastic leukemia cells after CD40 stimulation.

The development of immunotherapy in hematologic malignancies has been observed in the last few years. One of the approaches is the use of cancer vaccines based on leukemia-derived dendritic cells (DC). Recent studies from our laboratory and other laboratories have shown that CD40 stimulation improves leukemia cells immunogenicity and generates an antitumor immune response. The design of future cancer vaccines requires the knowledge concerning the function of dendritic cells including antigen processing. The aim of our present study was the assessment of antigen-processing machinery (APM) components in acute lymphoblastic leukemia (ALL) cells before and after CD40 stimulation at messenger RNA (mRNA) level. Twenty-five children with ALL were enrolled into the study. Leukemic cells were stimulated (or not) with CD40L and IL-4. Elements of the antigen-processing machinery (MB1, LMP2, LMP7, LMP10, TAP1, TAP2, calnexin, calreticulin, tapasin, ERp57, zeta, delta) were determined by real-time PCR technique. The expression of important costimulatory and adhesion molecules considered as DC markers (CD40, CD54, CD80, CD83, CD86) were determined at the mRNA (PCR) and protein (flow cytometry) levels. The following are the results of our study: (1) We noted an upregulation of all costimulatory and adhesion molecules at the mRNA and protein levels in ALL cells after the culture; (2) the significant rise in expression of nearly all APM components after CD40 stimulation was observed. This confirms specific stimulation of the antigen-processing system in ALL cells by CD40L. Future work should focus on the clinical significance of these findings for immunotherapy in leukemias.

CD40 stimulation induces differentiation of acute lymphoblastic leukemia cells into dendritic cells.

UNLABELLED: Despite the very high percentage of long-term remissions in acute lymphoblastic leukemia (ALL) in children, some of them suffer from recurrence of the disease. New treatment modalities, e.g. effective geno- and immunotherapy are needed. The use of neoplasmatic cells to present tumor antigens is one of the approaches in cancer vaccines. ALL cells lack the expression of costimulatory molecules and are poor antigen presenting cells (APCs) for T-cell activation. CD40/40L interaction stimulates B-cells to proliferate, differentiate, upregulate costimulatory molecules and increase antigen presentation. The aim of the study was to test the hypothesis that ALL cells can be turned into professional APCs by CD40L activation. Children with B-cell precursor ALL were enrolled into the study. Mononuclear cells from bone marrow or peripheral blood were stimulated with CD40L and interleukin 4. RESULTS: 1) after culture we noted upregulation of all assessed costimulatory, adhesion and activatory molecules i.e. CD1a, CD11c, CD40, CD54, CD80, CD83, CD86, CD123, HLA class I and II; 2) CD40L activated ALL cells induced proliferation of allogeneic T-cells (measured by [(3)H]thymidine incorporation). These results confirm the possibility of enhancing the immunogenicity of ALL cells with the CD40L system and indicate that this approach can be used in immunotherapeutic trials.