Lindstedt M, Johansson-Lindbom B, Borrebaeck C A K
Department of Immunotechnology, Lund University, S-220 07 Lund, Sweden.
Scand J Immunol. 2003 Apr;57(4):305-10. doi: 10.1046/j.1365-3083.2003.01217.x.
Follicular dendritic cells (FDCs) are the antigen (Ag)-trapping accessory cells of the germinal centres (GCs), essential for the development of humoral immune responses and memory. FDCs reside in the microenvironment of secondary lymphoid tissue where Ag-activated B cells expand, and undergo isotype switching and affinity maturation prior to becoming memory B cells. In addition to delivering Ag, FDCs also provide potent nonspecific accessory signals to the B cells, which are important for the GC reaction. In this report, we show that human tonsilar FDCs express the costimulatory molecule CD137. Surface expression of CD137 on FDCs was confirmed by immunofluorescent labelling and fluorescence-activated cell sorter analysis. CD137 was also highly expressed by the human cell line HK, which displays many characteristics of in vivo FDCs. The interaction between B cells and FDCs is essential for the GC reactions, and our finding suggests that CD137 plays a role in FDC-regulated B-cell responses.
滤泡树突状细胞（FDCs）是生发中心（GCs）捕获抗原（Ag）的辅助细胞，对体液免疫反应和记忆的发展至关重要。FDCs存在于次级淋巴组织的微环境中，在该环境中，抗原激活的B细胞得以扩增，并在成为记忆B细胞之前经历同种型转换和亲和力成熟。除了传递抗原外，FDCs还向B细胞提供强大的非特异性辅助信号，这对生发中心反应很重要。在本报告中，我们表明人类扁桃体FDCs表达共刺激分子CD137。通过免疫荧光标记和荧光激活细胞分选分析证实了FDCs表面CD137的表达。人细胞系HK也高度表达CD137，该细胞系具有许多体内FDCs的特征。B细胞与FDCs之间的相互作用对生发中心反应至关重要，我们的发现表明CD137在FDC调节的B细胞反应中发挥作用。
