The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia.
Innate Immun. 2011 Feb;17(3):338-52. doi: 10.1177/1753425910371396. Epub 2010 May 25.
Dendritic cells (DCs) serve as a link between the innate and adaptive immune systems. The activation state of DCs is crucial in this role. However, when DCs are isolated from lymphoid tissues, purified and placed in culture they undergo 'spontaneous' activation. The basis of this was explored, using up-regulation of DC surface MHC II, CD40, CD80 and CD86 as indicators of DC activation. No evidence was found for DC damage during isolation or for microbial products causing the activation. The culture activation of spleen DCs differed from that of Langerhans cells when released from E-cadherin-mediated adhesions, since E-cadherin was not detected and activation still occurred with β-catenin null DCs. Much of the activation could be attributed to DC-DC interactions. Although increases in surface MHC II levels occurred under all culture conditions tested, the increase in expression of CD40, CD80 and CD86 was much less under culture conditions where such interactions were minimised. DC-to-DC contact under the artificial conditions of high DC concentration in culture induced the production of soluble factors and these, in turn, induced the up-regulation of co-stimulatory molecules on the DC surface.
树突状细胞 (DCs) 是连接先天免疫和适应性免疫系统的桥梁。DCs 的激活状态在这一过程中至关重要。然而，当 DCs 从淋巴组织中分离出来，经过纯化并放入培养体系中时，它们会发生“自发”激活。本研究使用 DC 表面 MHC II、CD40、CD80 和 CD86 的上调来作为 DC 激活的指标，探索了这种自发激活的基础。在分离过程中未发现 DC 损伤的证据，也未发现微生物产物导致激活的证据。从 E-钙黏蛋白介导的黏附中释放的脾 DCs 的培养激活与朗格汉斯细胞不同，因为未检测到 E-钙黏蛋白，并且即使在 β-连环蛋白缺失的 DCs 中仍然发生激活。大部分激活可归因于 DC-DC 相互作用。尽管在所有测试的培养条件下表面 MHC II 水平都增加，但在这种相互作用最小化的培养条件下，CD40、CD80 和 CD86 的表达增加要少得多。在培养中高浓度 DC 下的人工条件下，DC 之间的接触诱导产生了可溶性因子，这些因子反过来又诱导 DC 表面共刺激分子的上调。
