Endocytosis and Recycling of Immune Complexes by Follicular Dendritic Cells Enhances B Cell Antigen Binding and Activation
Endocytosis and Recycling of Immune Complexes by Follicular Dendritic Cells Enhances B Cell Antigen Binding and Activation
复制标题
DOI：
10.1016/j.immuni.2013.02.023
复制
发表时间：
2013-06-27
期刊：
影响因子：
32.4
通讯作者：
Carroll, Michael C.
中科院分区：
文献类型：
--
作者：
Heesters, Balthasar A.;Chatterjee, Priyadarshini;Carroll, Michael C.
间质源性滤泡树突状细胞（follicular dendritic cells，FDCs）是抗原的主要储存库，所述抗原对于形成生发中心是必需的，所述生发中心是记忆和效应B细胞分化的位点。一个长期存在的问题是FDCs如何长时间保持抗原的天然形式，以及它们如何将其展示给特定的B细胞。我们发现FDC通过补体受体1和2（分别为CD 35和CD 21）从非同源B细胞获得补体包被的免疫复合物（IC），并通过肌动蛋白依赖性途径迅速内化。IC在非降解循环隔室内保持完整，并定期显示在细胞表面上，在那里它们可接近抗原特异性B细胞。这就解释了抗原是如何被保护不受损伤并长时间保留的，同时保持B细胞的可接近性。
Stromal-derived follicular dendritic cells (FDCs) are a major reservoir for antigen that are essential for formation of germinal centers, the site where memory and effector B cells differentiate. A long-standing question is how FDCs retain antigen in its native form for extended periods and how they display it to specific B cells. Here we found that FDCs acquired complement-coated immune complexes (ICs) from noncognate B cells via complement receptors 1 and 2 (CD35 and CD21, respectively) and rapidly internalized them by an actin-dependent pathway. ICs were retained intact within a nondegradative cycling compartment and were displayed periodically on the cell surface where they were accessible to antigen-specific B cells. This would explain how antigens are protected from damage and retained over long periods of time, while remaining accessible for B cells.