Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Case 906, 13288 Marseille Cedex 9, France.
J Exp Med. 2010 Jan 18;207(1):189-206. doi: 10.1084/jem.20091964. Epub 2009 Dec 28.
Recent studies have challenged the view that Langerhans cells (LCs) constitute the exclusive antigen-presenting cells of the skin and suggest that the dermal dendritic cell (DDC) network is exceedingly complex. Using knockin mice to track and ablate DCs expressing langerin (CD207), we discovered that the dermis contains five distinct DC subsets and identified their migratory counterparts in draining lymph nodes. Based on this refined classification, we demonstrated that the quantitatively minor CD207+ CD103+ DDC subset is endowed with the unique capability of cross-presenting antigens expressed by keratinocytes irrespective of the presence of LCs. We further showed that Y-Ae, an antibody that is widely used to monitor the formation of complexes involving I-Ab molecules and a peptide derived from the I-E alpha chain, recognizes mature skin DCs that express I-Ab molecules in the absence of I-E alpha. Knowledge of this extra reactivity is important because it could be, and already has been, mistakenly interpreted to support the view that antigen transfer can occur between LCs and DDCs. Collectively, these data revisit the transfer of antigen that occurs between keratinocytes and the five distinguishable skin DC subsets and stress the high degree of functional specialization that exists among them.
最近的研究挑战了朗格汉斯细胞（LCs）构成皮肤唯一抗原提呈细胞的观点，并表明真皮树突状细胞（DDC）网络极其复杂。使用基因敲入小鼠来追踪和清除表达 langerin（CD207）的 DC，我们发现真皮中存在五种不同的 DC 亚群，并在引流淋巴结中鉴定了它们的迁移对应物。基于这种精细化分类，我们证明了数量较少的 CD207+ CD103+ DDC 亚群具有独特的能力，可以交叉提呈角质形成细胞表达的抗原，而与 LCs 的存在与否无关。我们进一步表明，Y-Ae 是一种广泛用于监测涉及 I-Ab 分子和源自 I-E alpha 链的肽的复合物形成的抗体，它识别表达 I-Ab 分子而不表达 I-E alpha 的成熟皮肤 DC。了解这种额外的反应性很重要，因为它可能已经被错误地解释为支持抗原可以在 LCs 和 DDC 之间转移的观点。总的来说，这些数据重新审视了角质形成细胞与五种可区分的皮肤 DC 亚群之间发生的抗原转移，并强调了它们之间存在高度的功能专业化。
