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Peripheral Blood T Cells (peripheral + blood_t_cell)
Selected AbstractsRelationship between changes in interferon-, production by peripheral blood T cells and changes in peak expiratory flow rate in patients with chronic stable asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2002Y. I. Koh Summary Background Cytokines production by T helper lymphocytes (Th cells), which orchestrate the interplay of the different cells involved in airway inflammation of asthma, may be reflected in peripheral blood. Some studies have suggested that the Th cell cytokines by peripheral blood T cells correlate with asthma severity. Objective To investigate the relationship between changes in IFN-, production by peripheral blood T cells and changes in lung function in chronic stable asthmatics. Methods Sixteen patients with chronic stable moderate asthma aged 35,65 years (nine women) were recruited. Morning and evening peak expiratory flow rates (PEFR) monitoring and blood sampling for peripheral blood T cell culture, total IgE and blood eosinophils were performed at baseline and week 12. Levels of IFN-,, IL-4 and IL-5 in culture supernatants of peripheral blood T cell were determined by using enzyme-linked immunosorbent assay (ELISA) kits. Results Patients with increased IFN-, changes from baseline showed significantly increased changes in morning (P = 0.02) and evening (P < 0.05) PEFR compared with those with decreased IFN-, changes. The changes in IFN-, production and IFN-,: IL-4 ratio significantly correlated with the changes in morning PEFR (Rs = 0.59, P < 0.02; Rs = 0.63, P < 0.01, respectively) and tended to correlate with the changes in evening PEFR (Rs = 0.45, P = 0.08; Rs = 0.5, P = 0.05, respectively). The changes in IL-4 and IL-5 did not correlate with the changes in IgE and blood eosinophils, respectively. Conclusions These findings suggest that IFN-, may be associated with the alteration of lung function in asthmatics and play a role in the pathophysiology of chronic stable asthma. [source] Fucosyltransferase VII-positive, skin-homing T cells in the blood and skin lesions of atopic dermatitis patientsEXPERIMENTAL DERMATOLOGY, Issue 3 2008Yoshiko Mizukawa Abstract: Patients with atopic dermatitis (AD) have an abnormally increased frequency of cutaneous lymphocyte antigen (CLA)+ Th2 cells responsible for local inflammation; however, this is paradoxical, given the well-recognized defective capacity of Th2 cells to migrate to the skin sites of inflammation. These discrepant observations would stem from the ambiguity of CLA+ T cells, because CLA does not represent the epitope required for binding to E-selectin but the epitope generated by fucosyltransferase VII (Fuc-TVII) and because skin-homing T cells are composed of three distinct subpopulations; Fuc-TVII+ E-selectin ligand (ESL)+ CLA,, Fuc-TVII+ ESL+ CLA+ and Fuc-TVII, ESL, CLA+ cells. We therefore asked which subpopulations of skin-homing Th2 cells could be increased in the blood and skin lesions of AD. We analysed the frequencies of the three subpopulations in purified CD4+ peripheral blood T cells from AD patients and healthy controls by immunohistochemistry and flow cytometry. The Fuc-TVII+ CLA+ or CLA+ ESL+ CCR4+ cells were dramatically increased in frequency not only in the blood but also in the skin lesions of AD patients and this increase was related to the severity of the clinical symptoms. Our data indicate the clinical importance of identifying skin-homing T cells with the potent capacity to migrate into the skin by analysing their Fuc-TVII expression and E-selectin binding ability in patients with AD. [source] Expression of 5-lipoxygenase (5-LOX) in T lymphocytesIMMUNOLOGY, Issue 2 2007Jeanne M. Cook-Moreau Summary 5-lipoxygenase (5-LOX) is the key enzyme responsible for the synthesis of the biologically active leukotrienes. Its presence has been reported in cells of the myeloid lineage and B lymphocytes but has not been formally defined in T lymphocytes. In this study, we provide evidence for 5-LOX expression on both transcriptional and translational levels in highly purified peripheral blood T cells as well as in human T lymphoblastoid cell lines (MOLT4 and Jurkat). Messenger RNA (mRNA) of 5-LOX was amplified by conventional reverse transcription,polymerase chain reaction (RT-PCR; MOLT4 and Jurkat cells) and by in situ RT-PCR (T lymphocytes). 5-LOX protein expression was confirmed by Western blot and immunofluorescence studies. 5-LOX was present primarily in the cytoplasm with some nuclear localization and was translocated to the nuclear periphery after culture in a mitosis-supporting medium. Fluorescence-activated cell sorter analysis of different T-lymphocyte populations, including CD4, CD8, CD45RO, CD45RA, T helper type 2, and T-cell receptor-,, and -,, expressing cells, did not identify a differential distribution of the enzyme. Purified peripheral blood T lymphocytes were incapable of synthesizing leukotrienes in the absence of exogenous arachidonic acid. Jurkat cells produced leukotriene C4 and a small amount of leukotriene B4 in response to CD3,CD28 cross-linking. This synthesis was abolished by two inhibitors of leukotriene synthesis, MK-886 and AA-861. The presence of 5-LOX in T lymphocytes but the absence of endogenous lipoxygenase metabolite production compared to Jurkat cells may constitute a fundamental difference between resting peripheral lymphocytes and leukaemic cells. [source] CTLA-4 expression in T cells of patients with atopic dermatitisPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2005Sung Yon Choi Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4; CD152) is a surface molecule of activated T cells with sequence homologous to CD28, and may act as a negative regulator of T-cell activation. In murine animal models, cross-linkage of CTLA-4 molecules on the cell surface results in decreased T-cell proliferation, accompanied by increased interleukin (IL)-2 production and apotosis. To clarify the activation of peripheral blood T cells, we studied the CTLA-4 expression in 32 patients with atopic dermatitis who visited our institution, and 19 normal children who visited for pre-operative laboratory examination were used as normal controls. Whole blood was obtained from all subjects and stained with anti-CD3, anti-CD4, anti-CD8 monoclonal antibodies (mAb). After erythrocyte lysis with lysing solution, the cells were stained with anti-CTLA-4 mAb, and stained cells were analysed by fluorescence-activated cell sorter (FACScan) flow cytometer. Intracellular expression of CTLA-4 was significantly upregulated in peripheral blood CD3+ T cells (36.8%), CD4+ T cells (21.7%) and CD8+ T cells (18.7%) of patients with atopic dermatitis, compared with normal control (18.3%, 9.7%, 9.8%; respectively). Furthermore, CTLA-4-positive CD3+ T cells in patients with severe atopic dermatitis were significantly higher compared with milder group (42.8% vs. 32.2%). However, no significant difference was obtained in CD4+ and CD8+ T cells. Mean percentage of T cells expressing CTLA-4 in patients with atopic dermatitis was higher than the control group. These observations suggest the possibility that the disease activity can be correlated with the CTLA-4 level. [source] ORIGINAL ARTICLE: Women with Multiple Implantation Failures and Recurrent Pregnancy Losses have Increased Peripheral Blood T Cell ActivationAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2010Kwang Moon Yang Citation Yang KM, Ntrivalas E, Cho HJ, Kim NY, Beaman K, Gilman-Sachs A, Kwak-Kim J. Women with multiple implantation failures and recurrent pregnancy losses have increased peripheral blood T cell activation. Am J Reprod Immunol 2010 Problem, We aim to determine whether peripheral blood T cell activation is associated with repeated implantation failures or recurrent pregnancy losses (RPLs). Method of study, Women with a history of repeated implantation failure (n = 18) or RPLs (n = 17) comprise the study group. Normal fertile women (n = 11) are included as controls. Proportion of activated peripheral blood T cells (CD69+, CD154+) and Th1/Th2 cell ratios are measured by flow cytometric analysis. Results, Proportions (%) of CD4+/154+ of CD4+ and CD8+/154+ of CD8+ cells were significantly higher in study group than those of controls. Proportions (%) of CD3+/69+ of CD3+ cells and CD8+/69+ of CD8+ cells were significantly increased in study group compared to controls. Proportion (%) of CD4+/69+ cells significantly correlated with % CD4+/154+ cells (P = 0.003). Activated cytotoxic T cells (CD8+/154+, CD8+/69+) inversely correlated with INF-,/IL-10 producing CD3+/4+ T cell ratios. Proportion of activated CD3+/8+/69 and CD3+/8+/154+ cells was inversely correlated with IFN-,/IL-10 expressing CD3+/4+ T cell ratios. Conclusion, Women with MIFs or RPLs have increased T cell activation in peripheral blood lymphocytes, and T cell suppressor activation seems to be associated with decreased Th1 immunity. Further studies on T cell activation may elucidate molecular mechanisms controlling Th1 effectors. [source] Pharmacodynamics of Mycophenolate Mofetil after Heart Transplantation: New Mechanisms of Action and Correlations with Histologic Severity of Graft RejectionAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2002Markus J. Barten The primary mechanism of action in vivo of mycophenolate mofetil (MMF) is believed to be inhibition of lymphocyte proliferation. We used novel assays of lymphocyte functions (pharmacodynamics, PD) in whole blood collected from rat heart allograft recipients treated with MMF to investigate the mechanisms of action of the active metabolite of MMF, mycophenolate acid (MPA) in vivo. Allograft recipients were treated orally once daily with 3 different doses of MMF. Seven days after transplantation, blood was collected 24 h after the penultimate dose and several timepoints after the last dose, after which grafts were removed for microscopic grading of rejection. Lymphocytes in whole blood samples were mitogen stimulated through calcium-dependent and -independent signaling pathways. Inhibition of PD was measured by lymphocyte proliferation and expression of several surface antigens on T cells, and was calculated as area under the time-inhibition of immune function effect curve (AUE0,24 h). We found that inhibition of lymphocyte proliferation and antigen expression by MPA correlated highly with MMF-dose, MPA level and with the histologic severities of graft rejection (p <,0.05). In summary, MPA suppressed lymphocyte proliferation and expression of T-cell surface antigens in whole blood collected from MMF-treated allograft recipients, thus demonstrating the multiple mechanisms of suppression of rejection on peripheral blood T cells after MMF treatment. [source] Depletion of functionally active CD20+ T cells by rituximab treatmentARTHRITIS & RHEUMATISM, Issue 12 2009Esther Wilk Objective Rituximab is a therapeutic anti-CD20 antibody used for in vivo depletion of B cells in proliferative and autoimmune diseases. However, the mechanisms of action are not fully understood, since not all of the therapy-mediated effects can be explained by the depletion of antibody-secreting cells. In addition to B cells, there is also a small population of T cells coexpressing CD20 in all individuals. This study was conducted to examine the phenotype and function of CD3+CD20+ T cells in patients with rheumatoid arthritis (RA) and healthy controls. Methods The phenotype and apoptosis of peripheral blood mononuclear cells from healthy donors and RA patients were examined by 4-color fluorescence-activated cell sorting analyses. Cytokine production was determined by intracellular staining and measurement of cytokines in the supernatants. Proliferation of sorted T cell populations was analyzed using 3H-thymidine uptake assays. Results In healthy individuals, 0.1,6.8% of peripheral blood T cells (mean 1.6%; n = 142) coexpressed CD20, which was not significantly different from that in the peripheral blood of RA patients, in whom 0.4,2.6% of T cells (mean 1.2%; n = 27) were CD20+. During rituximab therapy, the CD20+ T cells along with the B cells were eliminated from the RA peripheral blood. Among the CD20+ T cells, 45% coexpressed CD8 and 55% coexpressed CD4. Polyclonal CD3+CD20+ cells were functionally characterized by constitutive cytokine production (i.e., interleukin-1, and tumor necrosis factor ,), a low proliferative capacity, a high activation state, and enhanced susceptibility to apoptosis. Conclusion These findings suggest that CD20+ T cells represent a terminally differentiated cell type with immune-regulatory and proinflammatory capacities. Depletion of CD20+ T cells may be an additional mechanism by which anti-CD20 therapy functions in patients with RA. [source] Folate receptor , as a potential delivery route for novel folate antagonists to macrophages in the synovial tissue of rheumatoid arthritis patientsARTHRITIS & RHEUMATISM, Issue 1 2009Joost W. Van Der Heijden Objective To determine the expression of folate receptor , (FR,) in synovial biopsy tissues and peripheral blood lymphocytes from rheumatoid arthritis (RA) patients and to identify novel folate antagonists that are more selective in the targeting and internalization of FR, than methotrexate (MTX). Methods Immunohistochemistry and computer-assisted digital imaging analyses were used for the detection of FR, protein expression on immunocompetent cells in synovial biopsy samples from RA patients with active disease and in noninflammatory control synovial tissues. FR, messenger RNA (mRNA) levels were determined by reverse transcription,polymerase chain reaction analysis. Binding affinities of FR, for folate antagonists were assessed by competition experiments for 3H-folic acid binding on FR,-transfected cells. Efficacy of FR,-mediated internalization of folate antagonists was evaluated by assessment of antiproliferative effects against FR,-transfected cells. Results Immunohistochemical staining of RA synovial tissue showed high expression of FR, on macrophages in the intimal lining layer and synovial sublining, whereas no staining was observed in T cell areas or in control synovial tissue. Consistently, FR, mRNA levels were highest in synovial tissue extracts and RA monocyte-derived macrophages, but low in peripheral blood T cells and monocytes. Screening of 10 new-generation folate antagonists revealed 4 compounds for which FR, had a high binding affinity (20,77-fold higher than for MTX). One of these, the thymidylate synthase inhibitor BCG 945, displayed selective targeting against FR,-transfected cells. Conclusion Abundant FR, expression on activated macrophages in synovial tissue from RA patients deserves further exploration for selective therapeutic interventions with high-affinity,binding folate antagonists, of which BCG 945 may be a prototypical representative. [source] Mature antigen-experienced T helper cells synthesize and secrete the B cell chemoattractant CXCL13 in the inflammatory environment of the rheumatoid jointARTHRITIS & RHEUMATISM, Issue 11 2008Antonio Manzo Objective Synovial B cells play a critical role in rheumatoid arthritis (RA), being involved in autoantibody synthesis, T cell activation, and cytokine production. CXCL13 is a B cell chemoattractant that is instrumental in synovial B cell organization; the regulatory determinants of CXCL13 in inflammation are poorly characterized. This study was undertaken to investigate the functional involvement of synovial T cells in the ectopic expression of CXCL13 in RA. Methods CXCL13 production and regulation were addressed using immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, multicolor flow cytometry, and enzyme-linked immunosorbent assay, by in situ,ex vivo analysis and in vitro functional assays with rheumatoid synovial tissue and primary cells. Results CXCL13 messenger RNA and protein expression and spontaneous CXCL13 secretion were detected in RA synovial fluid T cells but were not detected (or were detected only occasionally) in peripheral blood T cells. Analysis of tissue expression confirmed cytoplasm localization of CXCL13 in T lymphocytes infiltrating B cell follicles and small perivascular aggregates. Multicolor characterizations in synovial fluid demonstrated CXCL13 expression in antigen-experienced T helper cells, frequently characterized by terminal differentiation and the lack of the follicular helper T cell markers CXCR5 and BCL6 protein. In vitro functional assays revealed the enhancing effect of T cell receptor,CD28 engagement on CXCL13 production and secretion in primary cells. Conclusion Our findings define a new functional property of synovial T cells, demonstrating their active involvement in the local production of B cell chemoattractants, and support a direct contribution of the adaptive immune system and antigen-dependent signals in the mechanisms of B cell localization in RA. [source] Relationship between changes in interferon-, production by peripheral blood T cells and changes in peak expiratory flow rate in patients with chronic stable asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2002Y. I. Koh Summary Background Cytokines production by T helper lymphocytes (Th cells), which orchestrate the interplay of the different cells involved in airway inflammation of asthma, may be reflected in peripheral blood. Some studies have suggested that the Th cell cytokines by peripheral blood T cells correlate with asthma severity. Objective To investigate the relationship between changes in IFN-, production by peripheral blood T cells and changes in lung function in chronic stable asthmatics. Methods Sixteen patients with chronic stable moderate asthma aged 35,65 years (nine women) were recruited. Morning and evening peak expiratory flow rates (PEFR) monitoring and blood sampling for peripheral blood T cell culture, total IgE and blood eosinophils were performed at baseline and week 12. Levels of IFN-,, IL-4 and IL-5 in culture supernatants of peripheral blood T cell were determined by using enzyme-linked immunosorbent assay (ELISA) kits. Results Patients with increased IFN-, changes from baseline showed significantly increased changes in morning (P = 0.02) and evening (P < 0.05) PEFR compared with those with decreased IFN-, changes. The changes in IFN-, production and IFN-,: IL-4 ratio significantly correlated with the changes in morning PEFR (Rs = 0.59, P < 0.02; Rs = 0.63, P < 0.01, respectively) and tended to correlate with the changes in evening PEFR (Rs = 0.45, P = 0.08; Rs = 0.5, P = 0.05, respectively). The changes in IL-4 and IL-5 did not correlate with the changes in IgE and blood eosinophils, respectively. Conclusions These findings suggest that IFN-, may be associated with the alteration of lung function in asthmatics and play a role in the pathophysiology of chronic stable asthma. [source] Effect of leptin on activation and cytokine synthesis in peripheral blood lymphocytes of malnourished infected childrenCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007L. Rodríguez Summary Malnutrition compromises immune function, resulting in reduced resistance to infection. Recent animal and human studies have suggested that leptin is capable of modulating the immune response and that its levels, which are regulated by nutritional status, fall rapidly during starvation. Leptin deficiency is associated with impaired cell-mediated immunity, an increased incidence of infectious disease and an associated increase in mortality. The purpose of this study was to examine the effect of leptin on activation and cytokine production in peripheral blood T cells from malnourished children. The data obtained in the present study demonstrate that leptin produced an increase in the percentage of CD4+ and CD8+ cells producing interleukin (IL)-2 and interferon (IFN)-, in 24-h cultures. Moreover, leptin decreased the percentage of CD4+ and CD8+ cells producing IL-4 and IL-10, and enhanced activation of circulating T cells when co-stimulated by phorbol 12-myristate 13 acetate (PMA),ionomycin. Leptin enhanced the expression of activation markers CD69 and CD25 in both CD4+ and CD8+ cells after 5 h of stimulation. In conclusion, the results obtained show that leptin modulates CD4+ and CD8+ cell activation towards a T helper 1 (Th1) phenotype by stimulating the synthesis of IL-2 and IFN-,. In contrast, leptin decreases IL-4 and IL-10 production. Moreover, leptin enhanced the expression of CD69 and CD25 on CD4+ and CD8+ cells after stimulation with PMA,ionomycin. [source] | ||||||||||||||||||||||