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Vivo Stimulation (vivo + stimulation)
Kinds of Vivo Stimulation Selected AbstractsPostoperative serum attenuates LPS-induced release of TNF-, in orthopaedic surgeryJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007Olav Reikerås Abstract Studies with ex vivo stimulation of whole blood samples from injured patients have revealed a diminished production capacity for a broad range of secretory products, including inflammatory cytokines. Recent interest has focused on the release of mediators in serum that depress the cell-mediated immune response following trauma. The involvement of the lipid mediator prostaglandin E2 (PGE2) has been assumed because it is a potent endogenous immunosuppressor. In the present study, we tested the hypothesis that inhibitory substances circulating in the patient's serum after a major musculoskeletal trauma might impair leukocyte function by evaluating the effect of such serum on cytokine release in a whole blood model. Six females and three males undergoing elective total hip replacement were included in the study. Ex vivo LPS-induced TNF-, and IL-10 were measured in whole blood sampled preoperatively and added serum taken before, at the end of operation, and at postoperative days 1 and 6 with saline as negative control. LPS induced significant releases of TNF-, and IL-10 in whole blood. Addition of preoperative, postoperative, and day-1 postoperative serum did not alter the LPS-induced release of TNF-, as compared to saline. In the presence of serum from postoperative day 6, however, the expression of TNF-, was significantly reduced as compared to saline and preoperative serum (p,=,0.021 and 0.008, respectively). Neither of the serum samples altered the release of IL-10. PGE2 was significantly (p,=,0.008) increased in serum at postoperative day 6 as compared to preoperative levels. In conclusion, these data show that at day 6 after major orthopaedic surgery, the patient serum contained activity that inhibited ex vivo LPS-induced TNF-, release. The potent TNF-, inhibitory activity found at day 6 after injury correlated with increased levels of PGE2 and indicates cell-mediated hyporesponsiveness to a second stimulus. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1395,1400, 2007 [source] Antagonistic expression of hepatitis C virus and alpha interferon in lymphoid cells during persistent occult infectionJOURNAL OF VIRAL HEPATITIS, Issue 8 2007T. N. Q. Pham Summary., Detection of residual HCV in individuals with SVR after treatment of CHC can be significantly heightened by analyzing ex vivo mitogen-activated T and B lymphocytes and applying sensitive nucleic acid amplification assays. However, it remained unknown if synergistic activation of lymphocytes and monocytes would further augment HCV detection, if viral replication becomes universally upregulated in treated cells, and if examining sequential sera and lymphoid cells would improve detection of occult infection. Using paired sera and lymphoid cells collected 1 year apart from 17 individuals with normal liver enzymes for up to 72 months after SVR, it was found that simultaneous activation of lymphocytes and monocytes enhanced identification of silent HCV infection and revealed that in some cases monocytes were the principal immune cell type where HCV persisted. Testing of serial samples further increased detection of occult infection. Ultimately, by combining the above two approaches, all individuals with SVR were found to be silent carriers of HCV. Clonal sequencing revealed HCV variations in sera and lymphoid cells and evolution of viral genomes confirming ongoing virus replication. Surprisingly, similar to those with CHC, naive lymphoid cells from some individuals carried ,103 HCV copies/,g total RNA. HCV loads in naive lymphoid cells predetermined the outcome of ex vivo stimulation with respect to upregulation or inhibition of HCV replication. HCV RNA levels in occult infection were inversely proportional to the expression of IFN, and IFN-inducible MxA, but not to IFN, or tumour necrosis factor , in naive and mitogen-treated lymphoid cells. [source] Oxidoreductase macrophage migration inhibitory factor is simultaneously increased in leukocyte subsets of patients with severe sepsisBIOFACTORS, Issue 4 2008Lutz E. Lehmann M.D. Abstract The oxidoreductase Macrophage Migration Inhibitory Factor (MIF) is discussed as a promising target for immunomodulatory therapy in patients with severe sepsis. Moreover, MIF expresses tautomerase as well as thiol-protein oxidore-ductase activities and has a potential role in cellular redox homeostasis, apoptosis inhibition, endotoxin responsiveness as well as regulation of nuclear transcription factors. To further elucidate a potential role of intracellular MIF in severe sepsis, we assessed alterations of intracellular MIF content in peripheral blood leukocytes of patients with severe sepsis in comparison to healthy controls and non-septic patients after major surgery. Intracellular MIF was significantly elevated simultaneously in lymphocytes, B-cells, macrophages and granulocytes of patients with severe sepsis when compared to healthy control individuals (p < 0.05) and increased when compared to non-septic patients after major surgery. In parallel, plasma MIF levels were elevated in severe sepsis (p < 0.05). There was no difference of intracellular MIF in lymphocytes, B-cells, macrophages or granulocytes between surviving and non-surviving patients with severe sepsis (p > 0.05). However, in survivors LPS ex vivo stimulation increased MIF secretion but not in non-survivors of sepsis (p < 0.05). This finding underlines the role of intracellular MIF in inflammatory diseases. It suggests monitoring of intracellular MIF in further clinical and non-clinical research valuable. [source] Retroviral transduction of acute myeloid leukaemia-derived dendritic cells with OX40 ligand augments their antigen presenting activityBRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2004Soshi Yanagita Summary Recent studies have shown that human myeloid leukaemia cells can differentiate into dendritic cell (DC)-like cells (leukaemia-DCs) when cultured with a combination of cytokines. In the present study, we examined whether the transduction of leukaemia-DCs with OX40 ligand (OX40L), a member of the tumour necrosis factor (TNF) family, resulted in augmentation of their antigen presenting activity. Bicistronic retroviral vectors expressing both human OX40L and enhanced green fluorescent protein (EGFP) or EGFP alone were generated and used for transduction. Fresh leukaemic cells from five patients with acute myeloid leukaemia (AML) were isolated and retrovirally transduced with OX40L during the culture with a combination of cytokines from stem cell factor, fms -like tyrosine kinase (Flt)-3 ligand, granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-4 (IL-4) and TNF- ,. After 7 d, the majority of cells showed DC-like morphology, and expressed higher levels of CD80, CD86 and HLA-DR than fresh leukaemic cells. The transduction efficiency was 8·5,27·2%. Leukaemia-DCs transduced with OX40L elicited higher proliferative response of allogeneic CD4+ T cells than fresh leukaemic cells, non-transduced, or mock-transduced leukaemia-DCs. Co-culture of allogeneic CD4+ T cells with OX40L-transduced leukaemia-DCs was superior in the generation of interferon (IFN)- , producing CD4+ T cells and in production of IFN- ,. Furthermore, OX40L-transduced leukaemia-DCs could elicit significant proliferative response of human leucocyte antigen-matched T cells from the donor in allogeneic stem cell transplantation. These results indicate that retroviral transduction of leukaemia-DCs with OX40L augments their antigen presenting cell activity and thus renders them more suitable for tumour vaccines or ex vivo stimulation of leukaemia-specific T cells. [source] Vascular endothelial growth factor receptor-2: Its unique signaling and specific ligand, VEGF-ECANCER SCIENCE, Issue 9 2003Masabumi Shibuya Vascular endothelial growth factor receptor-2 (VEGFR-2/KDR/Flk-1) is a high-affinity receptor for vascular endothelial growth factor-A (VEGF-A), and mediates most of the endothelial growth and survival signals from VEGF-A. VEGFR-2 has a typical tyrosine kinase receptor structure with seven immunoglobulin (Ig)-like domains in the extracellular region, as well as a long kinase insert in the tyrosine kinase domain. It utilizes a unique signaling system for DNA synthesis in vascular endothelial cells, i.e. a phospholipase C,-protein kinaseC-Raf-MAP kinase pathway. Although VEGF-A binds two receptors, VEGFR-1 and -2, a newly isolated ligand VEGF-E (Orf-virus-derived VEGF) binds and activates only VEGFR-2. Transgenic mice expressing VEGF-ENZ-7 showed a dramatic increase in angiogenesis with very few side effects (such as edema and hemorrhagic spots), suggesting strong angiogenic signaling and a potential clinical utility of VEGF-E. VEGF family members bear three loops produced via three intramolecular disulfide bonds, and cooperation between loop-1 and loop-3 is necessary for the specific binding and activation of VEGFR-2 for angiogenesis. As it directly upregulates tumor angiogenesis, VEGFR-2 is an appropriate target for suppression of solid tumor growth using exogenous antibodies, small inhibitory molecules and in vivo stimulation of the immune system. [source] Inflammatory changes associated with circadian variation in pulmonary function in subjects with mild asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2004E. A. B. Kelly Summary Background Nocturnal enhancement of airway inflammation has been demonstrated in patients with asthma who have a significant drop in pulmonary function at night. Objective To investigate the circadian changes in airway inflammation and their relationship with variations in pulmonary function in subjects with mild atopic asthma. Methods Twelve asthma subjects were admitted to the hospital for two separate 24-h visits. Bronchoalveolar lavage (BAL) was performed at 04:00 hours during one visit, and at 16:00 hours during another visit. BAL cells were analysed for lymphocyte phenotype and the capacity to secrete cytokines following ex vivo stimulation with phytohaemagglutinin (PHA). Results The numbers of BAL lymphocytes and the percentage of CD4+ T cells were higher at 04:00 hours compared with 16:00 hours. At 04:00 hours, the forced expiratory volume in 1 s (FEV1) was inversely correlated with BAL lymphocytes and CD4+ cells. PHA-induced generation of IL-5 by BAL cells correlated with BAL eosinophils and CD4+ cells. Moreover, there was a linear relationship between the relative change (16:00,04:00 hours) in IL-5 and circadian variation in FEV1. Conclusions These data suggest that the circadian variation in lung function in asthma is associated with increased airway CD4+ lymphocyte numbers and their capacity to generate IL-5. Furthermore, in mild asthma, these circadian changes appear to fall into a continuous range, suggesting that day/night variations in airway inflammation and lung function occur on a continuum, rather than as an all-or-none phenomenon. [source] Anti-inflammatory effects of probiotic yogurt in inflammatory bowel disease patientsCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007M. Lorea Baroja Summary Our aim was to assess anti-inflammatory effects on the peripheral blood of subjects with inflammatory bowel disease (IBD) who consumed probiotic yogurt for 1 month. We studied 20 healthy controls and 20 subjects with IBD, 15 of whom had Crohn's disease and five with ulcerative colitis. All the subjects consumed Lactobacillus rhamnosus GR-1 and L. reuteri RC-14 supplemented yogurt for 30 days. The presence of putative regulatory T (Treg) cells (CD4+ CD25high) and cytokines in T cells, monocytes and dendritic cells (DC) was determined by flow cytometry from peripheral blood before and after treatment, with or without ex vivo stimulation. Serum and faecal cytokine concentrations were determined by enzyme-linked immunosorbent assays. The proportion of CD4+ CD25high T cells increased significantly (P = 0·007) in IBD patients, mean (95% confidence interval: CI) 0·84% (95% CI 0·55,1·12) before and 1·25% (95% CI 0·97,1·54) after treatment, but non-significantly in controls. The basal proportion of tumour necrosis factor (TNF)-,+/interleukin (IL)-12+ monocytes and myeloid DC decreased in both subject groups, but of stimulated cells only in IBD patients. Also serum IL-12 concentrations and proportions of IL-2+ and CD69+ T cells from stimulated cells decreased in IBD patients. The increase in CD4+ CD25high T cells correlated with the decrease in the percentage of TNF-,- or IL-12-producing monocytes and DC. The effect of the probiotic yogurt was confirmed by a follow-up study in which subjects consumed the yogurt without the probiotic organisms. Probiotic yogurt intake was associated with significant anti-inflammatory effects that paralleled the expansion of peripheral pool of putative Treg cells in IBD patients and with few effects in controls. [source] The kinetics of CD154 (CD40L) expression in peripheral blood mononuclear cells of healthy subjects in liver allograft recipients and X-linked hyper-IgM syndromeCLINICAL TRANSPLANTATION, Issue 6 2000A Bartlett The costimulatory pathways play a key role in T cell activation during allograft rejection (AR). Inhibition of the T cell costimulatory molecule CD154 (CD40 ligand) has been effective in producing long-term allograft survival in rodents and non-human primates. The role of the CD40-CD154 pathway in human orthotopic liver transplantation (OLT) has not been examined. Aim: To describe the patterns of CD154, CD69 and CD152 (CTLA4) expression in OLT recipients and to determine their temporal relationship to AR. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 15 OLT allograft recipients just prior to and for seven consecutive days postoperatively. Gene and protein expression of CD154, CD69 and CD154 were examined by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry (FC), respectively. Results: FC failed to demonstrate an up-regulation of CD154 and CD152 protein expression during the first postoperative week. Intracellular FC did not increase the sensitivity. There was an increased level of CD3+CD8+ T cells expressing CD69 at the time of rejection compared to that on day 0. RT-PCR demonstrated a sporadic expression of CD154 and CD69 mRNA, with no correlation to episodes of acute cellular rejection. In vitro stimulation of PBMCs revealed an impaired up-regulation of CD154 in patients receiving conventional immunosuppression compared to healthy controls. The assays were validated using positive and negative controls, including a family with X-linked hyper-IgM syndrome. Conclusion: We found no evidence of spontaneous CD154 gene or protein expression in PBMCs associated with acute rejection episodes following OLT. Immunosuppression resulted in impaired responses to ex vivo stimulation. Lymphocyte costimulatory pathways play a critical role in mediating acute allograft rejection. However, we found no evidence of spontaneous CD154 gene or protein expression in PBMCs associated with acute rejection episodes following OLT. Furthermore, stimulation in vitro resulted in less up-regulation of CD154 than for healthy controls. [source] | |||||||||||||