Hudrisier Denis, Aucher Anne, Puaux Anne-Laure, Bordier Christine, Joly Etienne
Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5089, 205 route de Narbonne, 31077 Toulouse Cedex 3, France.
J Immunol. 2007 Mar 15;178(6):3637-47. doi: 10.4049/jimmunol.178.6.3637.
Key events of T and B cell biology are regulated through direct interaction with APC or target cells. Trogocytosis is a process whereby CD4(+) T, CD8(+) T, and B cells capture their specific membrane-bound Ag through the acquisition of plasma membrane fragments from their cellular targets. With the aim of investigating whether the ability to trigger trogocytosis was a selective property of Ag receptors, we set up an assay that allowed us to test the ability of many different cell surface molecules to trigger trogocytosis. On the basis of the analysis of a series of surface molecules on CD4(+) T, CD8(+) T, and B cells, we conclude that a set of cell type-specific surface determinants, including but not limited to Ag receptors, do trigger trogocytosis. On T cells, these determinants include components of the TCR/CD3 as well as that of coreceptors and of several costimulatory molecules. On B cells, we identified only the BCR and MHC molecules as potentials triggers of trogocytosis. Remarkably, latrunculin, which prevents actin polymerization, impaired trogocytosis by T cells, but not by B cells. This was true even when the same Abs were used to trigger trogocytosis in T or B cells. Altogether, our results indicate that although trogocytosis is performed by all hemopoietic cells tested thus far, both the receptors and the mechanisms involved can differ depending on the lineage of the cell acquiring membrane materials from other cells. This could therefore account for the different biological consequences of Ag capture via trogocytosis proposed for different types of cells.
T细胞和B细胞生物学的关键事件是通过与抗原呈递细胞（APC）或靶细胞的直接相互作用来调节的。噬细胞作用是一个过程，通过该过程，CD4(+)T细胞、CD8(+)T细胞和B细胞从其细胞靶标获取质膜片段，从而捕获其特定的膜结合抗原。为了研究触发噬细胞作用的能力是否是抗原受体的选择性特性，我们建立了一种检测方法，使我们能够测试许多不同细胞表面分子触发噬细胞作用的能力。基于对CD4(+)T细胞、CD8(+)T细胞和B细胞上一系列表面分子的分析，我们得出结论，一组细胞类型特异性表面决定簇，包括但不限于抗原受体，确实能触发噬细胞作用。在T细胞上，这些决定簇包括TCR/CD3的成分以及共受体和几种共刺激分子的成分。在B细胞上，我们仅将BCR和MHC分子鉴定为噬细胞作用的潜在触发因素。值得注意的是，阻止肌动蛋白聚合的Latrunculin会损害T细胞的噬细胞作用，但不会损害B细胞的噬细胞作用。即使在T细胞或B细胞中使用相同的抗体来触发噬细胞作用，情况也是如此。总之，我们的结果表明，尽管迄今为止所有测试的造血细胞都能进行噬细胞作用，但所涉及的受体和机制可能因从其他细胞获取膜材料的细胞谱系而异。因此，这可以解释针对不同类型细胞提出的通过噬细胞作用捕获抗原的不同生物学后果。
