Young Louise J, Wilson Nicholas S, Schnorrer Petra, Proietto Anna, ten Broeke Toine, Matsuki Yohei, Mount Adele M, Belz Gabrielle T, O'Keeffe Meredith, Ohmura-Hoshino Mari, Ishido Satoshi, Stoorvogel Willem, Heath William R, Shortman Ken, Villadangos Jose A
The Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, Victoria 3050, Australia.
Nat Immunol. 2008 Nov;9(11):1244-52. doi: 10.1038/ni.1665. Epub 2008 Oct 12.
The importance of conventional dendritic cells (cDCs) in the processing and presentation of antigen is well established, but the contribution of plasmacytoid dendritic cells (pDCs) to these processes, and hence to T cell immunity, remains unclear. Here we showed that unlike cDCs, pDCs continued to synthesize major histocompatibility complex (MHC) class II molecules and the MHC class II ubiquitin ligase MARCH1 long after activation. Sustained MHC class II-peptide complex formation, ubiquitination and turnover rendered pDCs inefficient in the presentation of exogenous antigens but enabled pDCs to continuously present endogenous viral antigens in their activated state. As the antigen-presenting abilities of cDCs and pDCs are fundamentally distinct, these two cell types may activate largely nonoverlapping repertoires of CD4(+) T cells.
传统树突状细胞（cDC）在抗原加工和呈递中的重要性已得到充分证实，但浆细胞样树突状细胞（pDC）对这些过程以及对T细胞免疫的贡献仍不清楚。我们在此表明，与cDC不同，pDC在激活后很长时间仍继续合成主要组织相容性复合体（MHC）II类分子和MHC II类泛素连接酶MARCH1。持续的MHC II类-肽复合物形成、泛素化和周转使pDC在外源性抗原呈递方面效率低下，但使pDC能够在其激活状态下持续呈递内源性病毒抗原。由于cDC和pDC的抗原呈递能力存在根本差异，这两种细胞类型可能激活在很大程度上不重叠的CD4(+) T细胞库。
