Articles by Andra Necula in JoVE
استخراج المستضدات لفحوصات الأنسجة وظيفية Andra Necula1, Rochna Chand1, Batool Albatat1, Stuart I. Mannering1,2 1Immunology and Diabetes Unit, St. Vincent's Institute of Medical Research, 2Department of Medicine, University of Melbourne يوصف بروتوكول بسيط لإعداد مقتطفات من الأنسجة البشرية لاستخدامها كمصدر للمستضدات في المقايسات T-الخلية الوظيفية. هذا الأسلوب يسمح للقياس T-الخلية الردود على الأنسجة المشتقة من المستضدات
Other articles by Andra Necula on PubMed
Residual Methylprednisolone Suppresses Human T-cell Responses to Spleen, but Not Islet, Extracts from Deceased Organ Donors International Immunology. Jul, 2012 | Pubmed ID: 22378502 Pancreatic islets, transplanted into recipients with type 1 diabetes, are exposed to allogenic and auto-immune T-cell responses. We set out to develop an assay to measure these responses using PBMC. Our approach was to prepare spleen extract from the islet donors (allo-antigen) and islet extracts (auto-antigen). To our surprise, we found that spleen extracts potently inhibited the proliferation of human T cells driven by antigen (tetanus toxoid) and mitogen (anti-CD3 mAb, OKT3), whereas extracts prepared from pancreatic islets from the same donor did not suppress T-cell proliferation. Suppression mediated by spleen extracts was unaffected by blocking mAbs against the IL-10R, transforming growth factor-Î² or CD152 (CTLA-4). It was also unaffected by denaturing the spleen extracts by heating, exposing to reducing agents or protease digestion. Because deceased organ donors are commonly given the immunosuppressive glucocorticoid methylprednisolone prior to death, we hypothesized that suppression was due to residual methylprednisolone in the spleen extracts. Methylprednisolone could be detected by mass spectrometry in spleen extracts at concentrations that suppress T-cell proliferation. Finally, the glucocorticoid receptor antagonist mifepristone completely reversed the suppression caused by the spleen extracts. We conclude that extracts of human spleen, but not islets, from deceased organ donors contain sufficient residual methylprednisolone to suppress the proliferation of T-cells in vitro.