Plasmacytoid dendritic cells: recent progress and open questions.

Plasmacytoid dendritic cells (pDCs) are specialized in rapid and massive secretion of type I interferon (IFN-α/β) in response to foreign nucleic acids. Combined with their antigen presentation capacity, this powerful functionality enables pDCs to orchestrate innate and adaptive immune responses. pDCs combine features of both lymphocytes and classical dendritic cells and display unique molecular adaptations to nucleic acid sensing and IFN production. In the decade since the identification of the pDC as a distinct immune cell type, our understanding of its molecular underpinnings and role in immunity has progressed rapidly. Here we review select aspects of pDC biology including cell fate establishment and plasticity, specific molecular mechanisms of pDC function, and the role of pDCs in T cell responses, antiviral immunity, and autoimmune diseases. Important unresolved questions remain in these areas, promising exciting times in pDC research for years to come.

浆细胞样树突状细胞（pDCs）擅长在遇到外来核酸时快速大量分泌I型干扰素（IFN -α/β）。结合其抗原呈递能力，这种强大的功能使pDCs能够协调先天免疫和适应性免疫应答。pDCs兼具淋巴细胞和经典树突状细胞的特征，并在核酸感应和干扰素产生方面表现出独特的分子适应性。自从pDC被确定为一种独特的免疫细胞类型以来的十年间，我们对其分子基础以及在免疫中的作用的理解迅速发展。在此，我们综述pDC生物学的一些方面，包括细胞命运的确立和可塑性、pDC功能的特定分子机制，以及pDCs在T细胞应答、抗病毒免疫和自身免疫疾病中的作用。在这些领域仍存在一些重要的未解决问题，这预示着未来几年pDC研究将迎来激动人心的时刻。