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Activation Markers (activation + marker)
Kinds of Activation Markers Selected AbstractsClose association of CD8+/CD38bright with HIV-1 replication and complex relationship with CD4+ T-cell count,CYTOMETRY, Issue 4 2009Edouard Tuaillon Abstract Background: Measuring lymphocyte activation provides information in addition to CD4+ T-cell count for immune monitoring of HIV-1 infected patients. CD38 is a well-established activation marker that is generally analyzed on the whole population of CD8+ T-cells. Focusing specifically on CD38 high expression (CD8+/CD38bright) may be an interesting surrogate gating strategy because CD38bright characterizes principally activated memory cells. Methods: CD8+/CD38bright was investigated in 1,353 HIV-1 infected patients over a one-year period to establish relevant cutoff values and clarify the relationships of this marker with HIV-1 RNA viral load (VL) and CD4+ T-cell count. Results: The CD8+/CD38bright (>8,500 CD38 binding site per cells) is well correlated with HIV-1 VL (r = 0.87, P < 0.001) in this longitudinal follow-up of nonimmunodepressed patients that initiated antiviral therapy (ART). In aviremic patients on ART, the marker was highly predictive of VL rebound (sensitivity 93%, specificity 64% for a VL level of detection >200 copies/ml). While the CD8+/CD38bright moderately correlated with CD4+ T-cell count independently of the VL (r = ,0.37, P < 0.001), it increased dramatically in aviremic patient groups that exhibited profound CD4+ T-cell depletion (median 39% for CD4+ T-cell counts <50/mm3). This result indicates that other additional immunological and/or viral factors than readily detectable HIV-1 replication appears to be involved in T-cell activation of immunodepressed individuals. Conclusions: CD8+/CD38bright is an effective marker for monitoring T-cell activation, which is a central factor of HIV-1 pathogenesis. This gating strategy requires only a single additional staining in conventional four color CD4 protocols. © 2008 Clinical Cytometry Society [source] Platelet hyperactivity in clinical depression and the beneficial effect of antidepressant drug treatment: how strong is the evidence?ACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2004R. Von Känel Objective:, Platelet hyperactivity is thought to contribute to the increased coronary artery disease (CAD) risk in depression. This study reviewed the evidence for hyperactive platelets and for effects of antidepressant drug treatment on platelet ,stickiness' in clinical depression. Method:, By means of PubMed electronic library search, 34 studies in English were identified (1983,2003) and critically reviewed. Results:, In depression, flow cytometry studies allowing detection of subtle platelet activation states consistently found at least one platelet activation marker to be increased, while the bulk of platelet aggregation studies did not suggest increased platelet aggregability. Platelets seem to be more activated in depressed patients with CAD than in depressed individuals without CAD. The selective serotonin reuptake inhibitors normalized platelet hyperactivity in four studies. Conclusion:, Data on platelet activity in depression are inconclusive. To resolve this issue and its clinical implications, studies in larger sample sizes controlling for confounders of platelet functioning and prospectively designed are needed. [source] Phenotypic analysis of human peripheral blood regulatory T cells (CD4+FOXP3+CD127lo/,) ex vivo and after in vitro restimulation with malaria antigensEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2010Olivia C. Finney Abstract Regulatory T cells (Treg) play crucial roles in regulating autoimmune responses and immunity to tumors and infectious diseases. However, numerous subpopulations of Treg are now being described and the utility of various Treg markers is being reassessed. Here we report the results of a detailed phenotypic comparison of two supposedly regulatory human T-cell populations, namely CD4+FOXP3+ T cells and CD4+CD25hi T cells. We find that CD4+FOXP3+ cells are extremely heterogeneous with respect to CD25 expression and that FOXP3+ and CD25hi CD4+ T cells differ in their expression of chemokine receptors (CCR), CD95 and Bcl-2, suggestive of distinct migration characteristics and susceptibility to apoptosis. Further, we propose that CD25 expression should be regarded as an activation marker rather than as a defining marker of Treg. Lastly, CD4+FOXP3+ T cells activated in vitro with malaria antigen expressed the highest levels of CCR4 and CD95, and the lowest levels of CCR7, indicating that they are most likely generated from effector memory cells during an immune response and rapidly succumb to apoptosis at the end of the response. [source] Differential involvement of the prelimbic cortex and striatum in conditioned heroin and sucrose seeking following long-term extinctionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2005E. Donné Schmidt Abstract Relapse to drug taking is triggered by stimuli previously associated with consumption of drugs of misuse (cues) and involves brain systems controlling motivated behaviour towards natural reinforcers. In this study, we aimed to identify and compare neuronal pathways in corticostriatal systems that control conditioned heroin or natural reward (sucrose) seeking. To that end, rats were trained to self-administer heroin or sucrose in association with an identical compound cue. After more than 3 weeks of abstinence during extinction training, cue exposure robustly reinstated heroin and sucrose seeking, but induced distinct and even opposing changes in the expression of the neuronal activation marker zif268 in the prelimbic cortex and striatal complex, respectively. Because in the prelimbic area zif268 expression was enhanced during cue-induced heroin seeking but unaffected during sucrose seeking, a pharmacological intervention was aimed at this prefrontal region. Injection of a GABA agonist mixture within the prelimbic area enhanced conditioned heroin seeking, but had no effect on conditioned sucrose seeking. Our findings suggest a differential role of the prelimbic area and the striatum in the persistence of heroin vs. sucrose seeking following long-term extinction. [source] Functional characterization of human natural killer cells responding to Mycobacterium bovis bacille Calmette-GuérinIMMUNOLOGY, Issue 1 2004Semih Esin Summary The kinetics of activation and induction of several effector functions of human natural killer (NK) cells in response to Mycobacterium bovis bacille Calmette-Guérin (BCG) were investigated. Owing to the central role of monocytes/macrophages (MM) in the initiation and maintenance of the immune response to pathogens, two different experimental culture conditions were analysed. In the first, monocyte-depleted nylon wool non-adherent (NW) cells from healthy donors were stimulated with autologous MM preinfected with BCG (intracellular BCG). In the second, the NW cells were directly incubated with BCG, which was therefore extracellular. In the presence of MM, CD4+ T lymphocytes were the cell subset mainly expressing the activation marker, CD25, and proliferating with a peak after 7 days of culture. In contrast, in response to extracellular BCG, the peak of the proliferative response was observed after 6 days of stimulation, and CD56+ CD3, cells (NK cells) were the cell subset preferentially involved. Such proliferation of NK cells did not require a prior sensitization to mycobacterial antigens, and appeared to be dependent upon contact between cell populations and bacteria. Following stimulation with extracellular BCG, the majority of interferon-, (IFN-,)-producing cells were NK cells, with a peak IFN-, production at 24,30 hr. Interleukin (IL)-2 and IL-4 were not detectable in NK cells or in CD3+ T lymphocytes at any time tested. IL-12 was not detectable in the culture supernatant of NW cells stimulated with extracellular BCG. Compared to the non-stimulated NW cells, the NW cells incubated for 16,20 hr with BCG induced the highest levels of expression of apoptotic/death marker on the NK-sensitive K562 cell line. BCG also induced expression of the activation marker, CD25, and proliferation, IFN-, production and cytotoxic activity, on negatively selected CD56+ CD3, cells. Altogether, the results of this study demonstrate that extracellular mycobacteria activate several NK-cell functions and suggest a possible alternative mechanism of NK-cell activation as the first line of defence against mycobacterial infections. [source] Activation of human T lymphocytes under conditions similar to those that occur during exposure to microgravity: A proteomics studyPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2005Angela Risso Abstract A number of experiments, conducted under microgravity conditions, i.e. in space shuttle biolaboratories or in ground based systems simulating the conditions occurring in microgravity, show that in hypogravity, in vitro human lymphocyte activation is severely impaired. However, very early stimulation steps of T lymphocytes are not compromised, since CD69 receptor, the earliest membrane activation marker, is expressed by T cells at a level comparable to that observed on 1 g activated lymphocytes. Since CD69 engagement, together with submitogenic doses of phorbol esters, transduces an activation signal to T lymphocytes, we undertook a comparative study on the stimulation mediated through this receptor on human CD3+ cells cultured under conditions similar to those which occur during exposure to microgravity, i.e. in clinorotation, or at 1 g. During the early hours of activation, increased levels of intracellular calcium and increased mitochondrial membrane potential were detectable in clinorotating as well as in 1 g cells. However, after 48 hours clinorotation, interleukin 2 production by T lymphocytes was significantly reduced and cell proliferation was greatly decreased. By means of a differential proteomics approach on T cells activated in clinorotation or at 1 g for 48 hours, we were able to detect statistically significant quantitative protein alterations. Seven proteins with modified expression values were identified; they are involved in nucleic acids processing, proteasome regulation and cytoskeleton structure. [source] Increasing Circulating T-cell Activation Markers are Linked to Subsequent Implantation Failure After Transfer of In vitro Fertilized EmbryosAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 4 2003Carolyn B. Coulam Problem: Implantation determines success of in vitro fertilization (IVF) and embryo transfer (ET) cycles. Data are accumulating to support a role of the immune system in implantation. Most of the literature addresses the importance of natural killer (NK) cells in this process. The purpose of the current study is to examine the role of circulating T cells in implantation failure. Method of study: Blood from 22 women undergoing IVF/ET during November, 2001, was drawn on cycle day 9 and analyzed for the percentage of circulating T cells expressing the activation markers CD69+ and human leukocyte antigen (HLA)-DR and the suppressor marker CD11b using immunofluorescence and flow cytometry. These results were compared with total percentage circulating CD3, CD4 and CD8 cells as well as NK cells and pregnancy outcome that cycle. Results: Infertile women had significantly greater expression of the activation marker of CD69+ among CD8+ and CD4+ T cells and HLA-DR among CD4 cells than fertile women. No difference in expression of T cell suppressor marker of CD11b was noted when infertile and fertile women were compared. No correlations were observed when activated T cells were compared with circulating CD3+, CD4+, CD8+, activated NK cells and NK cytotoxicity. CD3+4+HLA-DR+ was expressed significantly less among successfully pregnant compared with unsuccessfully pregnant women. Conclusion: T-cell activation markers CD 69+ and HLA-DR+ are associated with increased implantation failure after IVF/ET. [source] Seasonal changes in suppressive capacity of CD4+ CD25+ T cells from patients with hayfever are allergen-specific and may result in part from expansion of effector T cells among the CD25+ populationCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2009A. E. Anderson Summary Background Suppression of allergen-stimulated peripheral blood CD4+ CD25, effector T cells by CD4+ CD25+ regulatory T cells obtained from subjects with allergic rhinoconjunctivitis is reduced during the pollen season when compared with out of season. Objective We examined possible explanations for this effect of seasonal pollen exposure on suppression of allergen responses. Methods CD4+ CD25, and CD4+ CD25+ T cells were isolated from blood obtained from 44 volunteers with allergic rhinoconjunctivitis during and out of the UK grass pollen season. Co-cultures were performed with grass pollen extract and house dust mite (HDM) to examine allergen specificity. The frequency of IL-5 and IL-10 producing cells was determined by ELISPOT and the expression of T cell activation markers and the CD25+ regulatory T cell-associated transcription factor Foxp3 were examined. Lactic acid stripping of IgE was used to determine IgE dependence of T cell responses. Results The seasonal reduction in suppression by CD4+ CD25+ T cells was confirmed and was shown to be allergen specific because suppression of HDM-stimulated cultures was not affected significantly. The CD4+ CD25+ population contained IL-5 and IL-10 producing cells but increases in their frequencies with seasonal pollen exposure were not significant. Both activation marker and Foxp3 expression increased during the pollen season. IgE stripping reduced CD4+ and CD4+ CD25, T cell responses to allergen, but had no effect on suppression by CD4+ CD25+ T cells. Conclusion The seasonal reduction in suppression of grass pollen-stimulated effector T cells by CD4+ CD25+ T cells is allergen specific and cannot be explained by increased IgE-facilitated allergen presentation. We suggest that changes in the proportion of effector to regulatory T cells among the CD25+ population isolated may partially explain these findings, and that trafficking to the site of allergic disease may reduce allergen-specific regulatory T cell numbers in peripheral blood. [source] Different cytokine production and activation marker profiles in circulating cutaneous-lymphocyte-associated antigen+ T cells from patients with acute or chronic atopic dermatitisCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2004C. Antúnez Summary Background Atopic dermatitis (AD) is an inflammatory skin disease whose lesions can have two stages: acute and chronic. In skin biopsies a biphasic pattern of cytokine expression has been shown, Th2 in acute lesions and Th1 in chronic AD lesions. Objective We investigated the expression of an activation marker and a homing receptor, as well as cytokine production, in different peripheral blood T cell subpopulations from AD patients with chronic (Group A) and acute lesions (Group B) and controls. Methods We evaluated 26 adult AD patients (12 Group A, 14 Group B) and 14 non-atopic controls. IgE was measured by immunoassay. CD4, CD8, cutaneous-lymphocyte-associated antigen (CLA) and human leucocyte antigen (HLA)-DR expression, and cytokine production (IL-2, IL-13, IFN-,, TNF-,, IL-10, IL-4) were analysed in mononuclear cells by flow cytometry. Results In Group B there was a significant increase in eosinophil levels and a non-significant increase in IgE. In Group A we found an increase in CLA+CD4+ cells (8.19±1.84) compared with controls (4.83±0.53) (P<0.05) and CD4+HLA-DR+ cells in the CLA+ subpopulation (45.54±15.40) compared with controls (30.49±6.07) (P<0.05). In the CLA+CD4+ subpopulation, there was a significant increase in IL-4, IL-13 and TNF-, production in Group B (12.46±7.7, 11.26±5.97, 43.92±15.55) compared with controls (5.34±3.50, 4.54±1.78, 19.29±9.97) with no differences in Group A. Conclusion Greater immunological differences were detected in peripheral blood from patients with acute compared with chronic lesions, especially in the circulating T cell-subset with skin tropism that preferentially responded to cutaneous allergens. This is the first demonstration of phenotypic changes in circulating CLA+ T cells between AD patients with acute and chronic lesions. [source] The effects of maximal treadmill graded exercise testing on haemorheological, haemodynamic and flow cytometry platelet markers in patients with systolic or diastolic heart failureEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2008I. Chung ABSTRACT Background, Acute exercise has been associated with activation of thrombosis, and this risk may be accentuated in patients with heart failure. Given the relation of platelets to atherothrombosis, we tested the hypothesis that acute exercise would adversely affect platelet indices and platelet activation markers in patients with systolic and diastolic heart failure. Materials and methods, We studied 20 patients with systolic heart failure (17 men, 3 women; mean age 64 ± 10 years, all with ejection fraction (EF) , 40%) and 20 patients with diastolic heart failure (14 men, 6 women; mean age 64 ± 8 years, mean EF = 66%) who were exercised to maximal intensity, who were compared to 13 healthy controls (6 men, 7 women; mean age 60 ± 4 years, mean EF = 73%). We measured platelet indices (platelet volume, mass and component) and platelet activation markers (platelet-bound CD62P%G, CD63%G and CD40L%G using flow cytometry, as well as plasma sCD40L and soluble P-selectin (sP-sel) levels). Results, Baseline Mean Platelet Volume (MPV), sP-sel, CD40L%G and CD63%G levels were significantly higher in patients with systolic and diastolic heart failure, when compared with controls. The mean exercise duration and VO2 peak in patients with systolic and diastolic heart failure were not significantly different, but lower than that seen in healthy controls. Following exercise, mean haematocrit, CD62P%G, and CD63%G significantly increased in all three subject groups (all P < 0·05). The proportional change in CD62P%G and CD63%G were not significantly different between healthy controls and heart failure patients (P > 0·05). Conclusion, Acute maximal graded exercise increases platelet activation markers, with no disproportionate differences between heart failure patients and healthy controls, despite the former group having a lower exercise tolerance and VO2 peak. [source] Interferon-, in healthy subjects: selective modulation of inflammatory mediatorsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2001J. De Metz Background It is suggested that interferon-, (IFN-,), like other cytokines, is a mediator in the host inflammatory response, which could be of importance in the pathophysiology of sepsis. The role of IFN-, in human host inflammatory responses, however, has not been studied. Design In a placebo-controlled trial we studied the acute effects of IFN-, administration on host inflammatory mediators in healthy men: i.e. the cytokine/chemokine cascade system, acute-phase proteins, activation markers of the innate cellular immunity and coagulation/fibrinolysis parameters. Results IFN-, increased plasma levels of interleukin-6 (IL-6), IL-8 and IFN-,-inducible protein-10 (IP-10) (P < 0·05), but did not affect plasma levels of other cytokines (IL-4, IL-10, tumour necrosis factor-,, IL-12p40/p70). Plasma concentrations of C-reactive protein and secretory phospholipase A2 both increased (P < 0·05). Plasma levels of the leucocyte activation marker elastase-,1,antitrypsin complexes increased after IFN-, administration (P < 0·05), IFN-, increased the percentage of high-affinity Fc,-receptor (Fc,RI) -positive neutrophils (P < 0·05), but did not affect the mean fluorescence intensity of Fc,RI on neutrophils. Procoagulant and profibrinolytic effects of IFN-, were evidenced by increased plasma levels of prothrombin fragment F1 + F2, tissue-plasminogen activator and plasmin-,2,antiplasmin complexes (P < 0·05). Conclusion We conclude that IFN-, selectively affects host inflammatory mediators in humans. [source] In vivo application of mAb directed against the ,, TCR does not deplete but generates "invisible" ,, T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2009Christian Koenecke Abstract mAb targeting the ,, TCR have been used for ,, T-cell depletion with varying success. Although the depletion-capacity of the anti-,, TCR mAb clone GL3 has been disputed repeatedly, many groups continue to use ,, T-cell depletion protocols involving the mAb clone UC7-13D5 and find significant biological effects. We show here that treatment with both GL3 and UC7-13D5 antibodies does not deplete ,, T cells in vivo, but rather leads to TCR internalization and thereby generates "invisible" ,, T cells. We addressed this issue using anti-,, TCR mAb injections into WT mice as well as into reporter TCR delta locus-histone 2B enhanced GFP knock-in mice, in which ,, T cells can be detected based on an intrinsic green fluorescence. Importantly, the use of TCR delta locus-histone 2B enhanced GFP mice provided here for the first time direct evidence that the "depleted" ,, T cells were actually still present. Our results show further that GL3 and UC7-13D5 mAb are in part cross-competing for the same epitope. Assessed by activation markers, we observed in vitro and in vivo activation of ,, T cells through mAb. We conclude that ,, T-cell depletion experiments must be evaluated with caution and discuss the implications for future studies on the physiological functions of ,, T cells. [source] CD5+ B cells with the features of subepithelial B cells found in human tonsilsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2007Mariella Dono Abstract This study describes a CD5+ B cell that differs from the majority of the CD5+ B cells from human tonsils. This cell, isolated from in vivo activated B cells, expressed activation markers and featured a CD23,, IgMhigh, IgDlow surface phenotype, responded to T cell-independent type-2 antigens in vitro, and was detected in the subepithelial (SE) areas, the tonsil equivalent of the splenic marginal zone (MZ). Most of the cells utilized unmutated Ig VH genes, although cells with mutated genes also were found, a finding confirmed by single-cell studies. Mutated sequences were more frequent in suspensions enriched for CD27+ cells. Repeated VDJ gene sequences were observed in different molecular clones from the same cell suspension, suggesting in situ expansion. These CD5+ B cells seem to share features with previously characterized tonsil CD5, SE B cells and differ from the majority of tonsil CD5+ B cells, which have the surface phenotype of follicular mantle B cells, lack activation markers, do not respond to T cell-independent antigens, and utilize unmutated VH genes. These data are discussed considering the present views on the origin of B cell subset populations and the relationships between MZ and B1 cells. [source] Cell-surface bound pertussis toxin induces polyclonal T cell responses with high levels of interferon-, in the absence of interleukin-12EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2003Ayako Wakatsuki Abstract Pertussis toxin (PTx), an exotoxin produced by Bordetella pertussis, has long been used as a mucosal adjuvant. We examined the T cell stimulatory properties of PTx in order to dissectits mechanisms of adjuvanticity. PTx or the B-oligomer of PTx (PTxB) failed to activate purified murine CD4+ or CD8+ T cells, as measured by a lack of proliferation or expression of early T cell activation markers. However, these T cells proliferated extensively in response to the toxin in the presence of syngeneic DC, and proliferation was accompanied by a high level of IFN-, production in the absence of IL-12. Interestingly, such responses were independent of signals mediated by MHC,TCR interaction. Both PTx and PTxB were found to bind stably to the surface of DC, and increased the adherence of DC to surrounding cells. These data suggest that polyclonal T cell responses mediated by the toxin are likely to be caused by the toxin bound on the surface of APC, either cross-linking cell surface molecules on T cells, or directly stimulating T cells together with the co-stimulatory molecules expressed on APC. B. pertussis may use this toxin as a mechanism to evade a specific immune response. [source] About the cutaneous targets of bexarotene in CTCL patientsEXPERIMENTAL DERMATOLOGY, Issue 8 2010Anne Chantal Knol Please cite this paper as: About the cutaneous targets of bexarotene in CTCL patients. Experimental Dermatology 2010; 19: e299,e301. Abstract:, There are several approved therapies for cutaneous T-cell lymphoma (CTCL). The retinoids are one of the major biologic response modifiers used in CTCL, producing good response rates but few complete responses. Bexarotene has been demonstrated to act on malignant T-cells by inducing their apoptosis, but nothing is known about its role on keratinocytes and Langerhans cells. Immunohistochemical analysis using CD1a, HLA-DR, ICAM-1 (activation markers), CD95 and CD40 (apoptosis markers) was conducted on frozen sections of bexarotene-exposed cutaneous explants and skin biopsy specimens from patients treated with bexarotene. None of the studied markers was significantly modulated both on cutaneous explants and on skin biopsy specimens after treatment with bexarotene, compared to controls. Langerhans cells and keratinocytes do not appear to play a central role in the therapeutic control of CTCL by bexarotene therapy. The main bexarotene's target thus remains T-cells by inducing their apoptosis, a mechanism that is different from the other retinoids used in CTCL. [source] The human basophil , a novel target of the neuropeptide alpha-melanocyte-stimulating hormoneEXPERIMENTAL DERMATOLOGY, Issue 8 2006M. Böhm There is increasing evidence that the basophil does not only play an important role in acute allergic reactions but also in the pathogenesis of chronic allergic disorders. Here we show that human basophils express melanocortin receptors (MC-Rs) and respond to alpha-melanocyte-stimulating hormone (alpha-MSH) with regulation of proallergic cytokine expression and modulation of basophil activation markers. Using primers against all known MC-R subtypes we demonstrate that the human basophil cell line KU812 expresses MC-1R. Expression of MC-1R on the surface of KU812 cells was confirmed by FACS analysis using an anti-MC-1R antibody. The MC-1R expressed by KU812 cells was functionally active as alpha-MSH induced intracellular cAMP in a dose-dependent manner. Moreover, alpha-MSH abrogated the effect of calcium ionophore A23187 on IL-4 mRNA expression in these cells. The relevance of the above findings was corroborated by showing that MC-1R surface expression is also detectable in basophils of leukocyte suspensions derived from whole human blood. Most interestingly, alpha-MSH was capable of suppressing the inductive effect of fMLP on surface expression of the basophil activation marker CD63 in leukocyte suspensions of atopic individuals. Likewise, alpha-MSH significantly blocked grass pollen-induced up-regulation of CD63 in leukocyte suspensions of patients with grass pollen allergy. Our findings highlight a novel functional dimension of alpha-MSH. In addition, MSH peptides may become a novel future therapeutic avenue in treating human allergic diseases. [source] Activation and deactivation of periventricular white matter phagocytes during postnatal mouse developmentGLIA, Issue 1 2010Mariya Hristova Abstract Brain microglia are related to peripheral macrophages but undergo a highly specific process of regional maturation and differentiation inside the brain. Here, we examined this deactivation and morphological differentiation in cerebral cortex and periventricular subcortical white matter, the main "fountain of microglia" site, during postnatal mouse development, 0,28 days after birth (P0,P28). Only macrophages in subcortical white matter but not cortical microglia exhibited strong expression of typical activation markers alpha5, alpha6, alphaM, alphaX, and beta2 integrin subunits and B7.2 at any postnatal time point studied. White matter phagocyte activation was maximal at P0, decreased linearly over P3 and P7 and disappeared at P10. P7 white matter phagocytes also expressed high levels of IGF1 and MCSF, but not TNFalpha mRNA; this expression disappeared at P14. This process of deactivation followed the presence of ingested phagocytic material but correlated only moderately with ramification, and not with the extent of TUNEL+ death in neighboring cells, their ingestion or microglial proliferation. Intravenous fluosphere labeling revealed postnatal recruitment and transformation of circulating leukocytes into meningeal and perivascular macrophages as well as into ramified cortical microglia, but bypassing the white matter areas. In conclusion, this study describes strong and selective activation of postnatally resident phagocytes in the P0,P7 subcortical white matter, roughly equivalent to mid 3rd trimester human fetal development. This presence of highly active and IGF1- and MCSF-expressing phagocytes in the neighborhood of vulnerable white matter could play an important role in the genesis of or protection against axonal damage in the fetus and premature neonate. © 2009 Wiley-Liss, Inc. [source] Pigment epithelium-derived factor induces the production of chemokines by rat microgliaGLIA, Issue 4 2005Asako Takanohashi Abstract Many studies have shown that pigment epithelium-derived factor (PEDF) has neurotrophic effects on retinal cells and hippocampal, spinal cord, and cerebellar granule cell neurons, but much less work has examined the effects of PEDF on glia. In this study, we show that PEDF changes microglial morphology within 1 h of exposure, to a more deactivated form, while having no effect on the expression of such activation markers as OX-42 and ED-1. In contrast, urea activates acid phosphatase, and PEDF blocks that activation. PEDF also activates NF,B, accompanied by the induction of mRNAs and proteins for the chemokines macrophage inflammatory protein-1, (MIP-1,, MIP-2, and MIP-3,. All the chemokines stimulate acid phosphatase activity, and high doses of MIP-2 and MIP-3,), alter the morphology of the microglia at 1 h after treatment. These results suggest that the use of PEDF for clinical treatments, such as for retinal neovascularization, brain injury, or ischemia, should be undertaken with caution because of the possibility of induction of inflammation caused by microglial or other immune cell migration in response to the chemokines induced by PEDF. © 2005 Wiley-Liss, Inc. [source] Effects of Helicobacter pylori Eradication on Platelet Activation and Disease Recurrence in Patients with Acute Coronary SyndromesHELICOBACTER, Issue 6 2004J. Ignasi Elizalde ABSTRACT Background., Platelet activation is consistently observed in animal models of Helicobacter pylori infection and could help to explain the alleged epidemiological association between H. pylori and coronary heart disease. Materials and Methods., Ninety-two patients with recent acute coronary syndromes were enrolled. Helicobacter pylori -positive patients were randomized to receive a 7-day course of omeprazole, amoxycillin and metronidazole or placebos. Two months later, H. pylori status was reassessed and baseline parameters, including soluble P-selectin and platelet surface expression of CD62P, CD63 and CD41, were measured again. Patients were followed-up for 1 year or until death or readmission. Results., No baseline differences were observed between H. pylori -positive and -negative cases. Among H. pylori -positive patients, 18 received placebo and 31 received active medication resulting in eradication in 21 cases. No differences were observed in inflammatory parameters or platelet activation markers between patients with persistent or resolved H. pylori infection. However, coronary events recurred at 6 and 12 months, respectively, in 35% and 55% of patients with persisting H. pylori infection compared with 10% and 25% of patients in whom H. pylori was either absent or eradicated (p = .01). Only final H. pylori status [RR 3.07 (95% CI 1.35,98)] and number of coronary risk factors [RR 2.58 (95% CI 1.51,4.41)] were independent predictors of recurrence. Conclusions., Infection with H. pylori does not induce significant platelet activation in patients treated for coronary disease. Helicobacter pylori -infected patients, however, may have an increased risk of recurrence of coronary events. [source] Inhibition of hepatic stellate cell proliferation and activation by the semisynthetic analogue of fumagillin TNP-470 in ratsHEPATOLOGY, Issue 5 2000Yan Qing Wang Proliferation and activation of hepatic stellate cells (HSCs) are critical steps for the development of postnecrotic fibrosis in the liver. The present study aimed to reveal the inhibitory effect of the semisynthetic analogue of fumagillin TNP-470 on these events for its possible use as an antifibrogenic agent. Rat models of carbon tetrachloride (CCl4)- and dimethylnitrosamine-induced hepatic fibrosis were used for an in vivo study. In both models, the fibrotic area was considerably decreased by concurrent repetitive subcutaneous injections of 30 mg/kg body weight of TNP-470. In CCl4 -induced fibrosis, factor VIII-related antigen-positive blood vessels, desmin-, or ,-smooth muscle actin (,SMA)-positive mesenchymal cells, bromodeoxyuridine (BrdU)-positive mesenchymal cells also decreased in number by treatment with TNP-470. In in vitro experiments, a supplement of 1,000 ng/mL TNP-470 suppressed BrdU incorporation and cyclins D1, D2, and E expression by cultured HSCs in the absence and/or presence of platelet-derived growth factor (PDGF). Expression of HSC activation markers, i.e., ,SMA and PDGF receptor ,, was also suppressed. The present results indicate that TNP-470 inhibits HSC proliferation by blocking the cell-cycle transition from G1 to S and HSC activation, and, as the consequence, prevents the progression of hepatic fibrosis, probably being coupled with its antiangiogenic effect. [source] Interleukin-18 overproduction exacerbates the development of colitis with markedly infiltrated macrophages in interleukin-18 transgenic miceJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2003TAKAHIRO ISHIKURA Abstract Background and Aim:, The authors have previously shown that production of interleukin (IL)-18 was increased in the inflamed mucosa of patients with Crohn's disease (CD) and blockade of IL-18 ameliorated the murine model of CD. This demonstrated that IL-18 plays a significant role during intestinal inflammation. However, the initial role of IL-18 during intestinal inflammation was unclear; therefore the susceptibility of IL-18 transgenic (Tg) mice to acute dextran sulfate sodium (DSS)-induced colitis was examined. Methods:, Interleukin-18 Tg and wild-type (WT) mice were fed 2.0% of DSS for 8 days. The total clinical scores (bodyweight loss, stool consistency, and rectal bleeding), colon length and histological scores were assessed. The expressions of surface markers and IL-18 on infiltrating lamina propria mononuclear cells were analyzed immunohistochemistrically. Mesenteric lymph node (MLN) cells were isolated and the expressions of CD4+ T-cell activation markers (CD69, CD25 and IL18R) were analyzed by flow cytometry. Results:, The IL-18 Tg mice exhibited an increased susceptibility to DSS-induced colitis, as shown by significantly increased clinical, histological scores, and more severe colonic shortening compared with WT mice. Immunohistochemical analysis revealed a significant increase of IL-18 production and CD11b+ macrophages but not CD4+ T cells in the inflamed mucosa in DSS-fed IL-18 Tg compared with DSS-fed WT mice. Furthermore, MLN cells revealed no evidence of increased CD4+ T-cell activation in DSS-fed IL-18 Tg. Conclusions:, These findings suggest that IL-18 overproduction in the mucosa plays an important role in the marked infiltration of macrophages and exacerbates colitis in IL-18 Tg mice. [source] Changes in HIV RNA viral load, CD4+ T-cell counts, and levels of immune activation markers associated with anti-tuberculosis therapy and cotrimoxazole prophylaxis among HIV-infected tuberculosis patients in Abidjan, Côte d'IvoireJOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Mireille Kalou We analyzed changes in plasma human immunodeficiency virus (HIV)-1 viral load, CD4+ T-cell count, and markers of immune activation markers at start of treatment of tuberculosis and 12 months after among 44 HIV-1-infected patients with newly diagnosed, sputum-smear positive for Mycobacterium tuberculosis pulmonary in fection. All patients received a standard regimen of 6 months of rifampicin and isoniazid with first 2 months of pyrazinamid with or without cotrimoxazole. Compared with values at start of treatment, median viral load increased by a median of 0.64 log10 copies/ml after 12 months of follow-up (P,=,0.0002). Median CD4+ T-cell counts were 393 cells/L at start of treatment and 370 cells/L after 12 months of follow-up (P,=,0.61). Levels of serum activation markers decreased significantly at 12 months of follow-up of the patients for both patients on standard and cotrimoxazole treatment. Levels of viral load, CD4+ T-cell counts, and markers of immune activation were not different for patients on standard treatment of tuberculosis compared with those on standard and cotrimoxazole treatment. Levels of serum activation markers decreased significantly at 12 months of follow-up of the patients for both patients on standard and cotrimoxazole treatment. Because viral load is a predictor of disease progression, its persistent elevated levels in blood of HIV-infected patients co-infected with tuberculosis, who successfully complete TB treatment, may account for the high mortality observed in this population. J. Med. Virol. 75:202,208, 2005. © 2004 Wiley-Liss, Inc. [source] Expression profiling reveals alternative macrophage activation and impaired osteogenesis in periprosthetic osteolysisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2008Panagiotis Koulouvaris Abstract Interactions between periprosthetic cells and prosthetic wear debris have been recognized as an important event in the development of osteolysis and aseptic loosening. Although the ability of wear debris to activate pro-inflammatory macrophage signaling has been documented, the full repertoire of macrophage responses to wear particles has not been established. Here, we examined the involvement of alternative macrophage activation and defective osteogenic signaling in osteolysis. Using real-time RT-PCR analysis of periprosthetic soft tissue from osteolysis patients, we detected elevated levels of expression of alternative macrophage activation markers (CHIT1, CCL18), chemokines (IL8, MIP1 ,) and markers of osteoclast precursor cell differentiation and multinucleation (Cathepsin K, TRAP, DC-STAMP) relative to osteoarthritis controls. The presence of cathepsin K positive multinuclear cells was confirmed by immunohistochemistry. Reduced expression levels of the osteogenic signaling components BMP4 and FGF18 were detected. Expression levels of TNF-,, IL-6, and RANKL were unchanged, while the anti-osteoclastogenic cytokine OPG was reduced in osteolysis patients, resulting in elevated RANKL:OPG ratios. In vitro studies confirmed the role of particulate debris in alternative macrophage activation and inhibition of osteogenic signaling. Taken together, these results suggest involvement in osteolysis of alternative macrophage activation, accompanied by elevated levels of various chemokines. Increased recruitment and maturation of osteoclast precursors is also observed, as is reduced osteogenesis. These findings provide new insights into the molecular pathogenesis of osteolysis, and identify new potential candidate markers for disease progression and therapeutic targeting. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:106,116, 2008 [source] Coagulation factors, activation markers and risk of coronary heart disease: the Northwick Park Heart StudiesJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2008G. D. O. LOWE [source] Comparison of basophil activation tests using CD63 or CD203c expression in patients with insect venom allergyALLERGY, Issue 9 2006B. Eberlein-König Background:, Flow cytometric basophil activation tests have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different activation markers (CD63 or CD203c) with distinct ways of regulation have been used after stimulation with various allergens. Objective:, It was the aim of the present study to compare basophil activation tests by measuring both CD63 and CD203c upregulation in patients with insect venom allergy. Materials and methods:, 43 patients with a history of insect venom anaphylaxis were examined. A careful allergy history was taken, and skin tests and determination of specific IgE-antibodies were performed. Basophil activation tests (BAT) using CD63 or CD203c expression were done after stimulation with different concentrations of bee and wasp venom extracts. 25 healthy subjects with negative history of insect venom allergy were studied as controls. Results:, The CD203c protocol showed a slightly higher sensitivity than the CD63 protocol (97% vs. 89%) with regard to patients' history. The magnitude of basophil response was higher with CD203c in comparison to CD63 for both insect venoms. Specificity was 100% for the CD63 protocol and 89% for the CD203c protocol with regard to controls with negative history and negative RAST. Conclusion:, These results support the reliability of basophil activation tests using either CD63 or CD203c as cellular tests in the in vitro diagnosis of patients with bee or wasp venom allergy with a slightly higher sensitivity for the CD203c protocol. [source] Treponema denticola immunoinhibitory protein induces irreversible G1 arrest in activated human lymphocytesMOLECULAR ORAL MICROBIOLOGY, Issue 3 2004W. Lee Oral spirochetes may contribute to the pathogenesis of a number of disorders including periodontal and periradicular diseases; however, the mechanism (s) by which these organisms act to cause disease is unknown. We have previously shown that extracts of the oral spirochete, Treponema denticola, contain an immunosuppressive protein (Sip) which impairs human lymphocyte proliferation. The objective of this study was to determine the mechanism by which Sip alters the proliferative response of lymphocytes. Human T-cells were activated by PHA in the presence or absence of Sip and cell cycle progression was assessed by flow cytometry. Cell cycle distribution was based upon DNA, RNA and protein content as well as expression of the activation markers; CD69 and IL-2R. Seventy-two hours following activation with PHA, cells were found in the G0, G1, S and G2/M phases of the cell cycle. In contrast, pretreatment with Sip resulted in a significant reduction of cells in the S and G2/M phases and a concomitant increase in the G1 phase. Sip did not alter the expression of the early activation markers CD69 and CD25R. To determine if G1 arrest resulted in activation of the checkpoint and cell death, we also monitored Sip-treated cells for apoptosis. Indeed, treatment with Sip resulted in both DNA fragmentation and caspase activation after 96 h. Our results indicate that Sip induces G1 arrest in human T-cells and, furthermore, that the arrest is irreversible, culminating in activation of the apoptotic cascade. We propose that if cell cycle arrest occurs in vivo, it may result in local and/or systemic immunosuppression and thereby enhance the pathogenicity of spirochetes and/or that of other opportunistic organisms. [source] Influence of Immunosuppression on Alloresponse, Inflammation and Contractile Function of Graft After Intestinal TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010J. Fujishiro In small bowel transplantation (SBTx), graft manipulation, ischemia/reperfusion injury and acute rejection initiate a severe cellular and molecular inflammatory response in the muscularis propria leading to impaired motility of the graft. This study examined and compared the effect of tacrolimus and sirolimus on inflammation in graft muscularis. After allogeneic orthotopic SBTx, recipient rats were treated with tacrolimus or sirolimus. Tacrolimus and sirolimus attenuated neutrophilic, macrophage and T-cell infiltration in graft muscularis, which was associated with reduced apoptotic cell death. Nonspecific inflammatory mediators (IL-6, MCP-1) and T-cell activation markers (IL-2, IFN-,) were highly upregulated in allogeneic control graft muscularis 24 h and 7 days after SBTx, and tacrolimus and sirolimus significantly suppressed upregulation of these mediators. In vitro organ bath method demonstrated a severe decrease in graft smooth muscle contractility in allogeneic control (22% of normal control). Correlating with attenuated upregulation of iNOS, tacrolimus and sirolimus treatment significantly improved contractility (64% and 72%, respectively). Although sirolimus reduced cellular and molecular inflammatory response more efficiently after 24 h, contrary tacrolimus prevented acute rejection more efficiently. In conclusion, tacrolimus and sirolimus attenuate cellular and molecular inflammatory response in graft muscularis and subsequent dysmotility of the graft after allogeneic SBTx. [source] Immunohistochemical Model to Predict Risk for Coronary Artery Disease and Failure in Heart Transplant PatientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2001Carlos A. Labarrere Transplant coronary artery disease is the leading cause of long-term morbidity and mortality in cardiac transplantation. We developed a model for early identification of patients who subsequently develop coronary artery disease and graft failure. Serial biopsies obtained from 141 cardiac allografts (5.5 ± 0.1 biopsies/patient) during the first 3 months post-transplant were evaluated immunohistochemically for deposition of myocardial fibrin, depletion of arteriolar tissue plasminogen activator, presence of arterial/arteriolar endothelial activation markers, and changes in vascular antithrombin. An immunohistochemical risk score was developed with a minimum value of 0 (normal) and a maximum value of 4 (most abnormal). Scores of 0 (low risk), 0.5,3.0 (moderate risk), and 3.5,4.0 (high risk) were analyzed for association with graft failure and development, severity, and progression of coronary artery disease detected using serial coronary angiograms (3.9 ± 0.2/patient). Allografts with high immunohistochemical risk scores in the first 3 months post-transplant developed more coronary artery disease (p,<,0.001), developed coronary artery disease earlier (p,<,0.001), developed more severe disease (p,<,0.001), and showed more disease progression (p,<,0.001) than allografts with moderate or low scores. Allografts with high immunohistochemical risk scores in the first 3 months post-transplant failed more (p,<,0.001) and failed earlier (p,<,0.001) than allografts with moderate or low scores. The present study demonstrates that early changes in the microvasculature are associated with impending coronary artery disease and graft failure in cardiac allograft recipients and suggests that treatment needs to be instituted early after transplantation in order to improve outcome. [source] Impaired activation-induced cell death promotes spontaneous arthritis in antigen (cartilage proteoglycan),specific T cell receptor,transgenic miceARTHRITIS & RHEUMATISM, Issue 10 2010Ferenc Boldizsar Objective To investigate whether genetic preponderance of a T cell receptor (TCR) recognizing an arthritogenic peptide of human cartilage proteoglycan (PG) is sufficient for development of arthritis. Methods We performed a longitudinal study using BALB/c mice expressing a TCR that recognizes the arthritogenic ATEGRVRVNSAYQDK peptide of human cartilage PG. PG-specific TCR,transgenic (PG-TCR,Tg) mice were inspected weekly for peripheral arthritis until 12 months of age. Peripheral joints were examined histologically, and T cell responses, T cell activation markers, serum cytokines, and autoantibodies were measured. Apoptosis and signaling studies were performed in vitro on T cells from aged PG-TCR,Tg mice. Results Spontaneous arthritis developed as early as 5,6 months of age, and the incidence increased to 40,50% by 12 months of age. Progressive inflammation began with cartilage and bone erosions in the interphalangeal joints, and later expanded to the proximal joints of the front and hind paws. Spontaneous arthritis was associated with a high proportion of activated CD4+ T cells, enhanced interferon-, and interleukin-17 (IL-17) production, and elevated levels of serum autoantibodies. PG-TCR,Tg mice lacking IL-4 developed arthritis earlier and at a higher incidence than IL-4,sufficient mice. Antigen-specific activation,induced cell death was diminished in vitro in CD4+ T cells of PG-TCR,Tg mice with spontaneous arthritis, especially in those lacking IL-4. Conclusion The presence of CD4+ T cells expressing a TCR specific for an arthritogenic PG epitope is sufficient to trigger spontaneous autoimmune inflammation in the joints of BALB/c mice. IL-4 appears to be a negative regulator of this disease, through attenuation of activation-induced cell death. [source] Recombinant Human Erythropoietin Treatment of Chronic Renal Failure Patients Normalizes Altered Phenotype and Proliferation of CD4-positive T LymphocytesARTIFICIAL ORGANS, Issue 3 2010Katarzyna A. Lisowska Abstract Patients with chronic renal failure (CRF) receive recombinant human erythropoietin (rhEPO) for the correction of anemia. However, rhEPO also has an immunomodulatory effect. Detailed changes of phenotype and function of CD4+ T lymphocytes in CRF patients receiving rhEPO have not been reported yet; their study may bring insight into understanding of this immunomodulatory action of rhEPO. Two groups of CRF patients were included into the study: those treated; and those not receiving rhEPO. The expression of activation markers on CD4+ lymphocytes was measured with flow cytometry, both ex vivo and in vitro. The kinetics of CD4+ T lymphocytes proliferation was calculated using a dividing cells tracing method and numerical approach. Significantly higher percentages of CD4+CD95+, CD4+HLA-DR+ cells, and lower percentages of CD4+CD69+ and CD4+CD28+ cells were observed in both rhEPO-treated and untreated patients when compared with healthy controls. Changes in the proportions of CD4+CD28+ and CD4+HLA-DR+ subpopulations were dependent on the type of rhEPO, being more pronounced for rhEPO,. CD4+ lymphocytes from untreated patients exhibited decreased expression of CD28 and CD69 after stimulation in vitro, whereas the expression of these antigens on lymphocytes of rhEPO-treated patients was similar to that observed in healthy controls. Fewer CD4+CD28+ T lymphocytes of untreated patients proliferated in vitro; these cells had longer G0,G1 time, which negatively correlated with surface expression of CD28. Our study confirms that rhEPO treatment normalizes activation parameters of CD4+ T lymphocytes and their proliferative capacity, which could explain earlier described immunomodulatory effects of rhEPO in patients suffering from CRF. [source] | |||||||||||||||||||||||||||||||