Hungarian Immunology

[The role of endothelial cells]

CERVENAK László

OCTOBER 20, 2007

Hungarian Immunology - 2007;6(05)

[The role of endothelial cells is much beyond the well known barrier function between blood and tissues. Several different stimuli converge in the endothelial cells, which in turn regulate a number of vital processes in the organisms. Among these processes one of the most important is the immune response. Endothelial cells modulate the homing of leukocytes by the production of adhesion molecules and cytokines depending on activation state, anatomic location and vessel type. Endothelial cells express MHC and costimulatory molecules, which enables them to present antigens to T cells. Antigen presentation may lead to activation or tolerance of T cells depending on the phenotype of endothelial cells. They also express complement regulatory molecules and produce several complement cascade proteins. Endothelial cells take part in the catabolism of immunoglobulins as well as in the removal of circulating immune complexes. Finally, endothelial cells regulate inflammation at different levels by several mechanisms, which may substantially determinate the progression of the immune response.]

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Hungarian Immunology

[Altered rate and absolute count of Th1/Th2 and Tc1/Tc2 lymphocytes in whole blood of patients with psoriasis]

ANTAL-SZALMÁS Péter, ALEKSZA Magdolna, GONDA Andrea, HERÉDI Emese, SIPKA Sándor, HUNYADI János, SZEGEDI Andrea

[BACKGROUND - Psoriasis is a chronic inflammatory skin disorder characterised by an altered rate of interferon (IFN)-γ and interleukin (IL)-4 producing lesional and peripheral blood CD4+ and CD8+ T cells. To further characterise the imbalance of these cells and cytokines the rate and as a novel approach the absolute cell count (ACC) of IFN-γ+, IL-4+ and IL-10+ Thelper and Tcytotoxic cells was determined in the peripheral blood of psoriatic individuals. MATERIALS AND METHODS - Cell-associated cytokine expression was determined using intracellular cytokine staining and flow cytometry, serum cytokine levels were measured by enzyme linked immunosorbent assays (ELISAs) in the samples of 35 psoriatic patients and 15 controls. RESULTS - Significantly elevated rate (p<0.008) and ACC (p<0.009) of CD4+/IFN-γ+ cells was observed in the patients (28.3±8.8% and 237,216±134,154 cells/ml) compared to the healthy controls (21.0+ 6.8% and 135,772±50,212 cells/ml). In contrast the rate and the ACC of CD4+/IL-4+ cells decreased significantly in psoriasis (0.45±0.67% vs. 1.01± 0.48%, p<0.0001; 3,229±3,724 vs. 5,117±4,171 cells/ml, p<0.05). In the case of CD8+ T cells only the rate and the ACC of CD8+/IL-10+ cells increased significantly in patients compared to controls (5.49±5.42% vs. 1.59±0.78%, p<0.003 and 19,799±17,412 vs. 5,564±2,794 cells/ml, p<0.03). Though higher IFN-γ and lower IL-4 and IL-10 serum concentrations were detected in psoriasis these differences between patients and controls were not significant. Comparing the different cytokine parameters the serum cytokine levels showed some correlation only with the ACC and not with the rate of cytokine positive cells. CONCLUSIONS - These results further prove the presence of an altered balance in cytokine regulation towards the Thelper 1 cytokines in psoriasis, besides indicate that application of the ACC of cytokine positive helper and cytotoxic T cells as a novel parameter can help in the characterisation of these changes in different disorders.]

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