Intracellular Cytokine Production (intracellular + cytokine_production)

Distribution by Scientific Domains

Selected Abstracts

Monitoring of monocyte functional state after extracorporeal circulation: A flow cytometry study

CYTOMETRY, Issue 1 2004
Silverio Sbrana
Abstract Background Cardiovascular surgery with cardiopulmonary bypass (CPB) induces systemic inflammation and postoperative complications depending on pro- and anti-inflammatory mechanisms. Activated polymorphonuclear cells and monocytes may be responsible for morbidity associated with CPB. Knowledge of the monocyte functional state in particular may help to develop protective interventions. Methods Samples were drawn from venous peripheral blood (basal condition, at 4 and 24 h after CPB) and coronary blood (before and after cardioplegic arrest) of 14 patients undergoing cardiac surgery. The following phenotypic and functional parameters of the monocyte population were studied by flow cytometry: surface molecules expression (CD18, CD11a, CD11b, CD14, CD15, CD45, HLA-DR, and Toll-like receptor [TLR]-4), myeloperoxidase (MPO) content, and intracellular cytokine production (tumor necrosis factor [TNF]-,, interleukin [IL]-1,, IL-6, and IL-8). Results Cardiac surgery with CPB induced down-modulation of surface molecules expression on peripheral monocytes, especially at 24 h after CPB, for CD18, CD11a, and CD11b (P < 0.003) and for the CD15 adhesive cluster (P = 0.0028) and HLA-DR (P < 0.001). At 4 h after CPB, downregulation was observed for CD14 (P = 0.004), CD45 (P = 0.014), and CD15 (P = 0.0056). A loss of MPO was detected in venous peripheral (at 24 h after CPB, P = 0.01) or coronary (at reperfusion, P < 0.02) blood. The CD15 cluster complex exhibited a down-modulation in coronary blood (at reperfusion, P = 0.0003). Spontaneous intracellular production of IL-1,, IL-6, and IL-8 decreased at 24 h after CPB (P < 0.05). Conclusions The down-modulation of integrins and adhesive receptor expression and the loss of MPO suggest a strong activation and shedding reaction of circulating monocyte after CPB, further exacerbated by contact with coronary ischemic vessels. The changes of differentiation antigens may reflect the appearance of a partially immature population immediately after CPB. The reduced proinflammatory cytokine production, observed at 24 h after CPB, suggests a functional polarization of circulating monocytes. 2003 Wiley-Liss, Inc. [source]

Excessive production of tumor necrosis factor-alpha by bone marrow T lymphocytes is essential in causing bone marrow failure in patients with aplastic anemia

Takeshi Hara
Abstract:, Aplastic anemia (AA) is regarded as an immunological disorder because of the clinical effect of immunosuppressive therapy. Recent studies have reported that cytokines play an important role in the development of AA. In the present study, we measured levels of T-cell derived intracellular cytokine production in peripheral blood and bone marrow (BM) of patients with AA. We demonstrated that BM lymphocytes, particularly CD4+ and CD8+ T cells, in patients with AA produced significantly higher amounts of tumor necrosis factor-alpha (TNF- ,), compared with lymphocytes in normal controls. We have previously reported that expression of TNF receptor (R)1 and TNFR2 in the CD34+ CD38, and CD34+ CD38+ fractions of patients with AA is significantly higher than those in normal control. These results indicate that BM stem cells in patients with AA may possess high sensitivity to TNF- ,. This in turn suggests that TNF- , affects hematopoiesis at an earlier stage in AA patients than in normal controls. We strongly support the hypothesis that a simultaneous increase in TNF- , production by BM lymphocytes and sensitivity of stem cells to TNF- , leads to BM failure in AA. [source]

An assessment of the immunological status of patients with renal cell carcinoma based on the relative abundance of T-helper 1- and -2 cytokine-producing CD4+ cells in peripheral blood

T. Onishi
Objective To assess the immunological status of patients with renal cell carcinoma (RCC), by analysing the proportion of cluster-of-differentiation 4-positive (CD4+) cells showing intracellular cytokine production, i.e. interferon-, derived from T-helper (Th) 1 and interleukin-4 derived from Th2 cells, among peripheral blood lymphocytes from these patients Patients, subjects and methods Peripheral blood samples (5 mL) were collected from 36 patients (mean age 61 years, range 44,78) with RCC before and after they underwent nephrectomy. The proportion of cytokine-producing CD4+ cells was determined by flow cytometric analysis after stimulating the cells with phorbol 12-myristate 13-acetate, ionomycin and brefeldin A, and staining the cells with fluorescein isothiocyanate-labelled anti-interferon-,, anti-interleukin-4 and anti-immunoglubulin-2b antibodies. The results were expressed as the percentage of cytokine-producing cells in the CD4+ population. As a control, peripheral blood obtained from 35 healthy volunteers (mean age 34 years, range 22,49) was also analysed. Results The proportion of CD4+ cells producing interferon-, and interleukin-4 was significantly higher (P < 0.04 and P < 0.001, respectively) in patients with RCC than in controls. The Th1/Th2 ratio (i.e. the ratio of CD4+ cells producing each cytokine) was significantly lower in patients with RCC (P < 0.001). There was a significant correlation in the controls between interferon-, and interleukin-4 production (r = 0.489, P < 0.01) but not in patients with RCC. The proportion of CD4+ cells producing interleukin-4 was significantly higher and the Th1/Th2 ratio significantly lower in patients with high-stage than in those with low-stage RCC (P < 0.05). The percentage of CD4+ cells producing interleukin-4 was significantly less after nephrectomy in those with low-stage RCC (P < 0.01) and the Th1/Th2 ratio significantly greater (P < 0.05) than before nephrectomy; there was no such trend in patients with high-stage RCC. Conclusion An evaluation of the production of interferon-, and interleukin-4 in CD4+ peripheral blood lymphocytes is useful for assessing the immunological status of patients with RCC; there is a change in the predominant response from Th1 to Th2 with increasing stage of RCC. [source]

Cyclical ischaemic preconditioning modulates the adaptive immune response in human limb ischaemia,reperfusion injury

P. J. Sullivan
Background: Reperfusion injury (RI) has significant local and systemic consequences. Ischaemic preconditioning (IPC) modulates RI and the innate immune response. This study examined whether IPC attenuates RI-mediated changes in lymphocyte populations and function following elective surgery. Methods: Twenty-five patients sustaining 1 h of tourniquet ischaemia during cruciate ligament reconstruction were randomized before surgery to three 5-min ischaemia cycles separated by 5 min of reperfusion, or to a control group. Systemic levels of interleukin (IL) 4 and interferon (IFN) ,, and surface expression of CD45ro/ra, CD62L and CD95 were measured. T cells were examined systemically and in stimulated serum co-culture to determine CD4/CD8 and Th1/Th2 shifts through intracellular cytokine production. Results: CD4 CD45ro cell numbers increased after RI without IPC, whereas CD8 cells expressing CD45ro and CD95 increased with IPC. Preconditioned serum in co-culture attenuated increases in CD4 and decreases in CD8 numbers, a process prevented by inhibition of antigen activation. Following RI, systemic IL-2 levels were significantly lower after IPC, whereas co-culture with post-RI serum increased proinflammatory intracellular cytokine production. Conclusion: IPC modulated T cell responses in limb RI through reduced activation and proinflammatory cytokine production by CD4 cells, while preventing CD4/CD8 derangement. IPC prevented lymphocyte-directed immune dysfunction. Copyright 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]