http://repub.eur.nl/res/aut/30781/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/37175/ 2012-01-01T00:00:00Z Sarcoidosis is a systemic inflammatory disorder characterized by granulomas. Although the aetiology is unknown, sarcoidosis is thought to be mediated by Th1 lymphocytes. Recently, IL-17A has been implicated in granuloma formation in various diseases, including tuberculosis. Therefore, we hypothesized that Th17 cells play a role in sarcoidosis, paralleling recent findings in autoimmune diseases such as RA. The aim of our study was to investigate the role of Th17 cells in sarcoidosis. T cells were investigated by intracellular flow cytometry and immunohistochemistry, in blood, bronchoalveolar lavages (BALs) and bronchial mucosal biopsies from a cohort of newly diagnosed sarcoidosis patients and healthy controls. Circulating memory CD4(+) T-cell populations of sarcoidosis patients contained significantly increased proportions of IL-17A(+) cells when compared with healthy controls. Interestingly, proportions of IL-17A/IFN-γ and IL-17A/IL-4 double-producing cells were significantly increased in blood of sarcoidosis patients and were present in substantial numbers in BAL. In granuloma-containing, but not in non-granulomatous sarcoidosis biopsies, we found significantly increased numbers of IL-17A(+) T cells, located in and around granulomas throughout the lamina propria. IL-22(+) T cells were increased in the subepithelial layer. Enhanced IL-17A expression in granulomas and the presence of IL-17A(+), IL-17A(+)IFN-γ(+) and IL-17A(+)IL-4(+)memory Th cells in the circulation and BAL indicate Th17 cell involvement in granuloma induction or maintenance in sarcoidosis. Therefore, neutralization of IL-17A activity may be a novel strategy to treat sarcoidosis. http://repub.eur.nl/res/pub/26498/ 2011-09-21T00:00:00Z The history of sarcoidosis begins in 1899 when the Norwegian dermatologist Ceasar Boeck described nodular skin lesions characterized by epitheloid cells and a few giant cells as multiple benign sarcoid of the skin. Now, many years later, a lot more is known about sarcoidosis. The definition of sarcoidosis is described in the American Thoracic Society statement on sarcoidosis in 1999: sarcoidosis is regarded as a multisystem disorder of unknown cause, commonly affecting young and middle aged adults, with bilateral hilar adenopathy, pulmonary infiltrates, eye and skin lesions. Also other organs like the liver, the spleen, lymph nodes, salivary glands, the heart, muscles, bones and the nervous system can be involved. The diagnosis is established when clinical and radiological findings are supported by histological evidence of non-caseating epitheloid cell granulomas. Granulomas caused by other diseases need to be excluded. Sarcoidosis affects people of all racial and ethnic groups and occurs at all ages although it usually develops before the age of 50 years, with a peak incidence at 20-39 years. The incidence of sarcoidosis varies widely all over the world with the highest incidence in the northern European countries. There is a predispondance of sarcoidosis in females. In America, the incidence of sarcoidosis in Afro-Americans is roughly three times higher compared to white americans. In black Americans the peak incidence occurs later in live and sarcoidosis is more often chronic and fatal. http://repub.eur.nl/res/pub/24431/ 2009-12-31T00:00:00Z Background: Dendritic cells (DCs) play a pivotal role in linking the innate and adaptive immune response and have been implicated in a variety of pulmonary diseases. Currently, studies on the role of DCs are limited by difficulties in isolating DCs from the lung. Surgical lung specimens are not readily available and purification of DCs from digested lung tissue is likely to induce phenotypical and functional changes. DCs obtained from the alveolar spaces are thought to represent the local microenvironment and can be obtained using minimally invasive techniques. We developed a novel method of isolating DCs from bronchoalveolar lavage (BAL) fluid. Methods: After removal of macrophages, the remaining BAL cells were stained with a lineage mix (CD3-, CD14-, CD16-, CD19-, CD56-FITC), CD11c and HLA-DR and sorted with a FACS ARIA. DAPI was used as a dead-live marker. mDCs were low autofluorescent, lineage mix negative, CD11c+and HLA-DR+cells. pDCs were CD11c-but CD123+. Morphological assessment of sorted mDCs and pDCs was performed. Sorted mDCs were tested in a mixed leukocyte reaction (MLR) with naive CD4+T cells and evaluated for T cell differentiation and cytokine production. With confocal microscopy DC-T cell interaction was assessed. Results: Using our sorting strategy, mDCs and pDCs, with a high purity upon FACS analysis of the sorted fraction, were obtained. These cells showed the morphological characteristics of DCs. Most importantly, mDCs were able to induce T cell proliferation and differentiation in a MLR, and interact with T cells as assessed by confocal microscopy. These results indicate the presence of functional DCs. Freezing and thawing of the BAL cells did not affect phenotype or T cell stimulatory capacity of the isolated DCs. Conclusion: Using a novel sorting strategy, functional mDCs can be isolated from BAL fluid, enabling a detailed study in pulmonary disease.