tailieunhanh - Báo cáo y học: "Platelet-Activating Factor Antagonists Decrease Follicular Dendritic-Cell Stimulation of Human B Lymphocytes"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Platelet-Activating Factor Antagonists Decrease Follicular Dendritic-Cell Stimulation of Human B Lymphocytes. | Original Article Platelet-Activating Factor Antagonists Decrease Follicular Dendritic-Cell Stimulation of Human B Lymphocytes Isaac Halickman MD Yolande Bastien MS Qianli Zhuang MD PhD Monty B. Mazer Baruch Toledano MD Bruce D. Mazer MD Abstract Both B-lymphoblastoid cell lines and tonsillar B lymphocytes express receptors for platelet-activating factor PAF . In lymph node germinal centres B lymphocytes interact with follicular dendritic cells FDCs which present antigen-containing immune complexes to B lymphocytes. FDCs have phenotypic features that are similar to those of stromal cells and monocytes and may therefore be a source of lipid mediators. In this study we evaluated the effects of the PAF antagonist WEB 2170 on the activation of tonsillar B lymphocytes by FDCs. FDCs were isolated from tonsils by Bovine Serum Albumin BSA gradient centrifugation. After being cultured for 6 to 10 days they were incubated with freshly isolated B cells in the presence or absence of the specific PAF receptor antagonist WEB 2170. B-lymphocyte proliferation was assessed by 3H -thymidine incorporation and immunoglobulin Ig G and IgM secretion was assessed by enzyme-linked immunosorbent assay ELISA . WEB 2170 10 6 to 10 8 M inhibited 3H -thymidine incorporation by up to 35 3 . Moreover the secretion of IgG and IgM was inhibited by up to 50 by WEB 2170 concentrations ranging from 10 6 to 10 8 M. There was no evidence of toxicity by trypan blue staining and the addition of WEB 2170 to B cells in the absence of FDCs did not inhibit the spontaneous production of IgG or IgM. The effect of the PAF antagonist is primarily on B lymphocytes as reverse transcription polymerase chain reaction detected little PAF receptor messenger ribonucleic acid mRNA from FDCs. These data suggest that endogenous production of PAF may be important in the interaction of B lymphocytes with FDCs. Antigen presentation is a crucial part of any immune response. Antigen-presenting cells coordinate the interaction .