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研究人员发现，血小板在驱动免疫系统对细菌作出反应的过程中发挥了重要作用，新成果发表在11月在线出版的《自然—免疫学》期刊上。 血小板的经典作用是它们参与了血凝反应。然而，Dirk Busch和同事指出，特定类型的细菌在血液中会被血小板迅速包裹，这一过程依赖于一种血小板所表达的分子GPIb。被包裹的细菌被运送到脾脏并在那里被树突状细胞所吞噬，树突状细胞在免疫系统功能的全面启动中发挥了重要作用。而未被血小板所包裹的细菌则被运送到巨噬细胞中，并在其中被摧毁，但这一过程不会让身体产生免疫记忆。（生物探索）
英文摘要：
A platelet-mediated system for shuttling blood-borne bacteria to CD8α+ dendritic cells depends on glycoprotein GPIb and complement C3
The acquisition of pathogen-derived antigen by dendritic cells (DCs) is a key event in the generation of cytotoxic CD8+ T cell responses. In mice, the intracellular bacterium Listeria monocytogenes is directed from the blood to splenic CD8α+ DCs. We report that L. monocytogenes rapidly associated with platelets in the bloodstream in a manner dependent on GPIb and complement C3. Platelet association targeted a small but immunologically important portion of L. monocytogenes to splenic CD8α+ DCs, diverting bacteria from swift clearance by other, less immunogenic phagocytes. Thus, an effective balance is established between maintaining sterility of the circulation and induction of antibacterial immunity by DCs. Other Gram-positive bacteria also were rapidly tagged by platelets, revealing a broadly active shuttling mechanism for systemic bacteria.
英文论文链接：http://www.nature.com/ni/journal/vaop/ncurrent/full/ni.2140.html
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