CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France.
PLoS One. 2010 Jan 14;5(1):e8716. doi: 10.1371/journal.pone.0008716.
T and B cells capture antigens via membrane fragments of antigen presenting cells (APC) in a process termed trogocytosis. Whether (and how) a preferential transfer of some APC components occurs during trogocytosis is still largely unknown. We analyzed the transfer onto murine T and B cells of a large panel of fluorescent proteins with different intra-cellular localizations in the APC or various types of anchors in the plasma membrane (PM). Only the latter were transferred by trogocytosis, albeit with different efficiencies. Unexpectedly, proteins anchored to the PM's cytoplasmic face, or recruited to it via interaction with phosphinositides, were more efficiently transferred than those facing the outside of the cell. For proteins spanning the PM's whole width, transfer efficiency was found to vary quite substantially, with tetraspanins, CD4 and FcRgamma found among the most efficiently transferred proteins. We exploited our findings to set immunodiagnostic assays based on the capture of preferentially transferred components onto T or B cells. The preferential transfer documented here should prove useful in deciphering the cellular structures involved in trogocytosis.
T 和 B 细胞通过抗原呈递细胞（APC）的膜片段捕获抗原，这个过程称为 trogocytosis。在 trogocytosis 过程中，某些 APC 成分是否（以及如何）优先转移仍然很大程度上未知。我们分析了在 APC 中具有不同细胞内定位或质膜（PM）中各种类型锚定的荧光蛋白在大量面板上转移到小鼠 T 和 B 细胞上的情况。只有后者通过 trogocytosis 转移，尽管效率不同。出乎意料的是，锚定在 PM 细胞质侧的蛋白，或通过与磷酸肌醇的相互作用募集到 PM 的蛋白，比那些面向细胞外部的蛋白转移效率更高。对于跨越 PM 整个宽度的蛋白质，转移效率发现变化相当大，其中四跨膜蛋白、CD4 和 FcRgamma 被发现是转移效率最高的蛋白质之一。我们利用我们的发现，基于将优先转移的成分捕获到 T 或 B 细胞上，建立了免疫诊断检测方法。这里记录的优先转移应该有助于解析参与 trogocytosis 的细胞结构。
