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Cytokine Stimulation (cytokine + stimulation)

Distribution by Scientific Domains

Medical Sciences	66%
Life Sciences	33%

Selected Abstracts

Cytokine Stimulation Promotes Increased Glucose Uptake Via Translocation at the Plasma Membrane of GLUT1 in HEK293 Cells

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2010
Angara Zambrano PhD
Abstract Interleukin-3 (IL-3) and granulocyte/macrophage colony-stimulating factor (GM-CSF) are two of the best-characterized cell survival factors in hematopoietic cells; these factors induce an increase in Akt activity in multiple cell lines, a process thought to be involved in cellular survival. It is known that growth factors require sustained glucose metabolism to promote cell survival. It has been determined that IL-3 and GM-CSF signal for increased glucose uptake in hematopoietic cells. Interestingly, receptors for IL-3 and GM-CSF are present in several non-hematopoietic cell types but their roles in these cells have been poorly described. In this study, we demonstrated the expression of IL-3 and GM-CSF receptors in HEK293 cells and analyzed their effect on glucose uptake. In these cells, both IL-3 and GM-CSF, increased glucose uptake. The results indicated that this increase involves the subcellular redistribution of GLUT1, affecting glucose transporter levels at the cell surface in HEK293 cells. Also the data directly demonstrates that the PI 3-kinase/Akt pathway is an important mediator of this process. Altogether these results show a role for non-insulin growth factors in the regulation of GLUT1 trafficking that has not yet been directly determined in non-hematopoietic cells. J. Cell. Biochem. 110: 1471,1480, 2010. © 2010 Wiley-Liss, Inc. [source]

Cytokine stimulation and the choice of promoter are critical factors for the efficient transduction of mouse T cells with HIV-1 vectors

THE JOURNAL OF GENE MEDICINE, Issue 2 2010
David E. Gilham
Abstract Background HIV-1 fails to successfully infect mouse T cells as a result of several blocks in the viral replication cycle. We investigated whether this also impacted on the use of HIV-1 derived lentiviral vectors for stable gene transfer into mouse T cells. Methods Freshly isolated primary mouse T cells were immediately mixed with lentiviral vectors encoding an enhanced green fluorescent protein marker gene and transduction frequency was determined after 5 days of culture. Results Optimal transduction required both mouse T cell activation and cytokine support. Furthermore, transduction was also dependent upon the promoter chosen, with the rank order of potency being PGK > EF1 > SFFV > CMV. HIV-1 lentiviral vectors also efficiently transduced cytokine-stimulated T cells (in the absence of antibody driven T cell activation), albeit with a lower level of transgene expression compared to fully-activated T cells. Conclusions The present study demonstrates that primary mouse T cells can be efficiently transduced with HIV-1 lentiviral vectors, opening up prospects for their use in mouse models of gene-modified adoptive cellular therapy. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Natural killer cells in viral hepatitis: facts and controversies

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2010
Mario U. Mondelli
Eur J Clin Invest 2010; 40 (9): 851,863 Abstract Background, Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major human hepatotropic pathogens responsible for a large number of chronic infections worldwide. Their persistence is thought to result from inefficiencies of innate and adaptive immune responses; however, very little information is available on the former. Natural killer (NK) cells are a major component of innate immunity and their activity is tightly regulated by several inhibitory and activating receptors. Design, In this review, we examine controversial findings regarding the role of NK cells in the pathogenesis of acute and chronic liver disease caused by HCV and HBV. Results, Recent studies built up on technical advances to identify NK receptors and their functional correlates in this setting. While NK cells seem to behave correctly during acute hepatitis, it would appear that the NK cytotoxic potential is generally conserved in chronic hepatitis, if not increased in the case of HCV. In contrast, their ability to secrete antiviral cytokines such as interferon ex vivo or after cytokine stimulation is severely impaired. Conclusions, Current evidence suggests the existence of an NK cell functional dichotomy, which may contribute to virus persistence, while maintaining low-level chronic liver inflammation. The study of liver-infiltrating NK cells is still at the very beginning, but it is likely that it will shed more light on the role of this simple and at the same time complex innate immune cell in liver disease. [source]

Education of hyporesponsive NK cells by cytokines

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2009
Kerstin Juelke
Abstract NK-cell tolerance to self is mediated via engagement of inhibitory receptors by cognate MHC molecules. This event is critical for NK-cell education to achieve functional competence. Thus, NK cells expressing self-MHC-specific inhibitory receptors are responsive to activating stimuli while those lacking such receptors are hyporesponsive. Nevertheless, the mechanisms underlying NK-cell education are still poorly understood. Here, we show that after stimulation with cytokines, hyporesponsive NK cells acquire stable expression of killer Ig-like receptors (KIR) as reflected by DNA hypomethylation of their KIR locus. Remarkably, only hyporesponsive NK cells that acquire KIR in the presence of their cognate MHC molecule gain functional competence and this process can occur in the absence of any accessory cells. Acquisition of competence does not result in autoreactivity, since acquired KIR are functional and therefore able to inhibit NK-cell cytotoxicity. Our data demonstrate that competent NK cells can be generated by cytokine stimulation, suggesting that NK-cell education might not only be an early event which takes place during NK-cell development but might also occur in the periphery during an immune response. [source]

Function of indoleamine 2,3-dioxygenase in corneal allograft rejection and prolongation of allograft survival by over-expression

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2006

Abstract Indoleamine 2,3-dioxygenase (IDO) suppresses T cell responses by its action in catabolising tryptophan. It is important in maintenance of immune privilege in the placenta. We investigated the activity of IDO in the cornea, following corneal transplantation and the effect of IDO over-expression in donor corneal endothelium on the survival of corneal allografts. IDO expression was analysed and functional activity was quantified in normal murine cornea and in corneas following transplantation as allografts. Low levels of IDO, at both mRNA and protein levels, was detected in the normal cornea, up-regulated by IFN-, and TNF. Expression of IDO in cornea was significantly increased following corneal transplantation. However, inhibition of IDO activity in vivo had no effect on graft survival. Following IDO cDNA transfer, murine corneal endothelial cells expressed functional IDO, which was effective at inhibiting allogeneic T cell proliferation. Over-expression of IDO in donor corneal allografts resulted in prolonged graft survival. While, on one hand, our data indicate that IDO may augment corneal immune privilege, up-regulated IDO activity following cytokine stimulation may serve to inhibit inflammatory cellular responses. While increasing IDO mRNA expression was found in allogeneic corneas at rejection, over-expression in donor cornea was found to significantly extend survival of allografts. [source]

Rapid and reliable generation of invariant natural killer T-cell lines in vitro

IMMUNOLOGY, Issue 3 2009
Asako Chiba
Summary Several tools have proved useful in the study of invariant natural killer T (iNKT) cells, including CD1d-deficient mice, J,281-deficient mice, synthetic lipid antigens and antigen-loaded CD1d tetramers. However, the generation and examination of long-term primary murine iNKT cell lines in vitro has been challenging. Here, we show the rapid generation of iNKT cell lines from splenic iNKT cells of V,14 T-cell receptor (TCR) transgenic (Tg) mice. These purified iNKT cells were stimulated by bone marrow-derived dendritic cells (BMDCs) loaded with ,-galactosylceramide (,GalCer) and cultured with interleukin (IL)-2 and IL-7. iNKT cells proliferated dramatically, and the cell number exhibited a 100-fold increase within 2 weeks and a 105 -fold increase in 8 weeks after repeated stimulation with ,GalCer. The iNKT cell lines consisted of iNKT cells expressing V, chains including V,8.1/8.2, V,14, V,10, V,6 and V,7, and responded to stimulation with ,GalCer presented both by BMDCs and by plate-bound CD1d. In addition, the iNKT cell lines produced interferon (IFN)-, when activated by lipopolysaccharide (LPS) or CpG oligodeoxynucleotide (ODN)-stimulated BMDCs. Further, we show that iNKT cell lines produced cytokines in response to microbial antigens. In summary, high-yield iNKT cell lines were generated very rapidly and robustly expanded, and these iNKT cells responded to both TCR and cytokine stimulation in vitro. Given the desire to study primary iNKT cells for many purposes, these iNKT cell lines should provide an important tool for the study of iNKT cell subsets, antigen and TCR specificity, activation, inactivation and effector functions. [source]

Reactive Oxygen Species and Signal Transduction

IUBMB LIFE, Issue 1 2001
Toren Finkel
Abstract Increasing evidence suggests a role for intracellular reactive oxygen species (ROS) as mediators of normal and pathological signal transduction pathways. In particular, a growing list of recent reports have demonstrated a rapid and significant increases in intracellular ROS following growth factor or cytokine stimulation. These ROS appear essential for a host of downstream signaling events. Biochemical characterization of this ligand-activated ROS production has revealed important information regarding the molecular composition of the cellular oxidases and the regulation of their activity by small GTPases. Work is proceeding on identifying strategies to identify how ROS might specifically regulate signaling pathways by altering the activity of direct target molecules. This review will focus on the progress in the rapid emerging area of oxidant or redox-dependent signal transduction and speculate how these insights might alter our view and treatment of diseases thought to be caused by oxidative stress. [source]

Mechanical strain increases cytokine and chemokine production in bronchial fibroblasts from asthmatic patients

ALLERGY, Issue 1 2009
F. Le Bellego
Background:, Mechanical strain and cytokine stimulation are two important mechanisms leading to airway remodeling in asthma. The effect of mechanical strain on cytokine secretion in airway fibroblasts is not known. The aim of this study was to determine whether bronchial and nasal fibroblasts differentially alter cytokine secretion in response to mechanical strain. Methods:, We measured secretion of the pro-fibrotic cytokine, interleukin-6 (IL-6), and the pro-inflammatory cytokines, IL-8 and monocyte chemotactic protein 1, before and after mechanical strain in bronchial fibroblasts obtained from asthmatic patients [asthmatic bronchial fibroblasts (BAF)] and normal volunteers [normal bronchial fibroblasts (BNF)], and in nasal fibroblasts (NF) obtained from nasal polyps. Cells were grown on flexible membranes and a mechanical strain of 30% amplitude, 1 Hz frequency was applied for 3, 6 and 24 h. Control cells were unstrained. IL-6, IL-8 and monocyte chemotactic protein 1 was measured after 24 h strain using enzyme-linked immunoassay; mRNA was measured by real time polymerase chain reaction. We also measured mRNA for versican, a matrix proteoglycan, known to be upregulated in the asthmatic airway wall. Results:, In unstrained conditions, no differences in cytokine secretion were observed. After 24 h strain, BAF secreted more IL-6 than BNF. Mechanical strain increased IL-8 mRNA in BAF, BNF and NF; and IL-6 and versican mRNA, in BAF, only. Conclusions:, Cytokine responses to mechanical strain varied in different airway fibroblast populations, and depended on the site of origin, and the underlying inflammatory state. Strain resulted in IL-6 upregulation and increased message for extracellular matrix protein in bronchial fibroblasts from asthmatic patients only, and may reflect these patients' propensity for airway remodeling. [source]

Phenotypic and functional characterization of mature dendritic cells from pediatric cancer patients

PEDIATRIC BLOOD & CANCER, Issue 7 2007
Joannes F.M. Jacobs MD
Abstract Background Dendritic cells (DCs) are the most potent antigen-presenting cells of the immune system. Clinical trials have demonstrated that mature DCs loaded with tumor-associated antigens can induce tumor-specific immune responses. Theoretically, pediatric patients are excellent candidates for immunotherapy since their immune system is more potent compared to adults. We studied whether sufficient amounts of mature monocyte-derived DCs can be cultured from peripheral blood of pediatric cancer patients. Procedure DCs from 15 pediatric patients with an untreated primary tumor were cultured from monocytes and matured with clinical grade cytokines. Phenotype and function were tested with flow cytometry, mixed lymphocyte reaction (MLR), and an in vitro migration assay. DCs of children with a solid tumor were compared with monocyte-derived DCs from age-related non-malignant controls. Results Ex vivo-generated monocyte-derived DCs from pediatric patients can be generated in numbers sufficient for DC vaccination trials. Upon cytokine stimulation the DCs highly upregulate the expression of the maturation markers CD80, CD83, and CD86. The mature DCs are six times more potent in inducing T cell proliferation compared to immature DCs. Furthermore, mature DCs, but not immature DCs, express the chemokine receptor CCR7 and have the capacity to migrate in vitro. Conclusions These data indicate that mature DCs can be generated ex vivo to further optimize DC-vaccination trials in pediatric cancer patients. Pediatr Blood Cancer 2007;49:924,927. © 2007 Wiley-Liss, Inc. [source]

Intrathoracic nontuberculous mycobacterial infections in otherwise healthy children

PEDIATRIC PULMONOLOGY, Issue 11 2009
Alexandra F. Freeman MD
Abstract Background Nontuberculous mycobacterial (NTM) infection is typically associated with lymphadenitis in immune competent children, and disseminated disease in children with immune deficiencies. Isolated pulmonary NTM disease is seen in cystic fibrosis, and is increasingly recognized in immunocompetent elderly women, where it is associated with an increased incidence of cystic fibrosis transmembrane regulator (CFTR) mutations. Thoracic NTM infection has been reported rarely in otherwise healthy children. We aimed to determine whether otherwise healthy children with pulmonary NTM disease had immunologic abnormalities or CFTR mutations. Clinical presentations of five otherwise healthy children with pulmonary NTM were reviewed. Immunologic studies were performed including a complete blood cell count (CBC), flow cytometric lymphocyte phenotyping and IFN-gamma receptor expression, in vitro cytokine stimulation, and serum immunoglobulin levels. Mutational analysis was performed for CFTR. The children ranged in age from 12 months to 2.5 years at diagnosis. Four presented with new onset wheezing or stridor failing bronchodilator therapy. One child was asymptomatic. Endobronchial lesions and/or hilar lymph nodes causing bronchial obstruction were identified in all patients. Mycobacterium avium complex was cultured from four patients, and Mycobacterium abscessus from one patient. All patients were successfully treated with anti-mycobacterial therapy with or without surgery. No definitive immunologic abnormalities were identified. No clinically significant mutations were found in CFTR. Pulmonary NTM infection should be considered in otherwise healthy young children presenting with refractory stridor or wheezing with endobronchial lesions or hilar lymphadenopathy. It does not appear to be associated with recognized underlying immune deficiency or CFTR mutations. Pediatr Pulmonol. 2009; 44:1051,1056. ©2009 Wiley-Liss, Inc. [source]

Evidence for a pathogenetic role of interleukin-18 in cutaneous lupus erythematosus

ARTHRITIS & RHEUMATISM, Issue 10 2008
Dong Wang
Objective Cutaneous manifestations are the most common clinical features of lupus erythematosus (LE). The aim of this study was to analyze differences in the inflammatory response of keratinocytes from patients with cutaneous LE (CLE) compared with healthy controls. Methods Keratinocytes from LE patients and controls were cultured from epidermal stem cells of the hair follicle of anagen head hairs. Functional responses of keratinocytes to cytokine stimulation were determined by flow cytometry and enzyme-linked immunosorbent assay. Biopsy samples of lesional skin were analyzed by immunohistochemistry. Results Keratinocytes from CLE patients expressed higher levels of IL-18 receptor on their cell surface in response to tumor necrosis factor , (TNF,) or interferon-, stimulation. In response to IL-18 stimulation, these cells produced large amounts of TNF,. Of note, in the presence of IL-18, CLE keratinocytes failed to express IL-12. IL-12 has previously been shown to protect keratinocytes from ultraviolet irradiation,induced apoptosis. Keratinocytes from LE patients were more prone to die upon exposure to IL-18, and this increased apoptosis was abrogated by blockade of endogenously produced TNF, as well as by the addition of exogenous IL-12. IL-18 was highly expressed in biopsy samples of lesional skin from CLE patients. Conclusion Our results demonstrate an intrinsic difference in the inflammatory response of keratinocytes and indicate an autocrine feedback loop involving TNF,, IL-18, and IL-12 family members. Our results suggest that IL-18 may occupy an important position in the cytokine hierarchy in CLE, indicating the potential benefit of a local agent that blocks IL-18 activity in the treatment of the manifestations of CLE. [source]

The influence of antisense oligonucleotides against STAT5 on the regulation of normal haematopoiesis in a bone marrow model

CELL PROLIFERATION, Issue 3 2004
M. Ba, kiewicz-Masiuk
The STAT5 (signal transducers and activators of transcription) proteins are members of a family of signal transducers and activators of transcription that can be activated after cytokine stimulation. Their binding to promoters of different genes influences cell proliferation, differentiation and survival. It is suggested that they play an important role in haematopoiesis, however, the question of the real function of STAT5 proteins requires further examination. The aim of our study was to investigate the role of STAT5 in the proliferation and apoptosis of normal haematopoietic bone marrow cells derived from heparinized cadaveric organ donors (HCOD). We applied antisense oligodeoxynucleotides (ODNs) to block STAT5A and STAT5B at the mRNA level and the reverse transcription polymerase chain reaction method to study STAT5 mRNA expression in the cells after incubation with ODNs. Moreover, we performed Western blot analysis of the STAT5A protein after exposure to antisense STAT5A. We analysed the clonogenicity of the colony-forming unit of granulocytes,macrophages and the burst-forming unit of erythrocytes in methylcellulose cultures according to the type and the dose of ODNs. We also examined apoptosis induced in bone marrow mononuclear and CD34+ cells by employing annexin V staining and the TUNEL method using flow cytometry (FACScan). We found that the perturbation of STAT5 expression decreased the clonogenicity of bone marrow haematopoietic cells. However, we did not observe any significant increase in the percentage of apoptotic cells after incubation with antisense ODNs. It was concluded that the STAT5 proteins play a significant role in the proliferation of human bone marrow cells harvested from HCOD. These proteins might be critical in the regulation of haematopoiesis, especially under stress conditions. [source]