树突状细胞中依赖Toll样受体的吞噬体微管形成促进吞噬体相互作用以优化MHC-II抗原呈递。

TLR-dependent phagosome tubulation in dendritic cells promotes phagosome cross-talk to optimize MHC-II antigen presentation.

作者信息

Mantegazza Adriana R, Zajac Allison L, Twelvetrees Alison, Holzbaur Erika L F, Amigorena Sebastián, Marks Michael S

机构信息

Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA 19104; Department of Physiology and.

Department of Physiology and Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; and.

出版信息

Proc Natl Acad Sci U S A. 2014 Oct 28;111(43):15508-13. doi: 10.1073/pnas.1412998111. Epub 2014 Oct 13.

Abstract

Dendritic cells (DCs) phagocytose large particles like bacteria at sites of infection and progressively degrade them within maturing phagosomes. Phagosomes in DCs are also signaling platforms for pattern recognition receptors, such as Toll-like receptors (TLRs), and sites for assembly of cargo-derived peptides with major histocompatibility complex class II (MHC-II) molecules. Although TLR signaling from phagosomes stimulates presentation of phagocytosed antigens, the mechanisms underlying this enhancement and the cell surface delivery of MHC-II-peptide complexes from phagosomes are not known. We show that in DCs, maturing phagosomes extend numerous long tubules several hours after phagocytosis. Tubule formation requires an intact microtubule and actin cytoskeleton and MyD88-dependent phagosomal TLR signaling, but not phagolysosome formation or extensive proteolysis. In contrast to the tubules that emerge from endolysosomes after uptake of soluble ligands and TLR stimulation, the late-onset phagosomal tubules are not essential for delivery of phagosome-derived MHC-II-peptide complexes to the plasma membrane. Rather, tubulation promotes MHC-II presentation by enabling maximal cargo transfer among phagosomes that bear a TLR signature. Our data show that phagosomal tubules in DCs are functionally distinct from those that emerge from lysosomes and are unique adaptations of the phagocytic machinery that facilitate cargo exchange and antigen presentation among TLR-signaling phagosomes.

摘要

树突状细胞(DCs)在感染部位吞噬如细菌等大颗粒,并在成熟的吞噬体内逐渐将其降解。DCs中的吞噬体也是模式识别受体(如Toll样受体(TLRs))的信号平台,以及货物衍生肽与主要组织相容性复合体II类(MHC-II)分子组装的场所。尽管来自吞噬体的TLR信号刺激吞噬抗原的呈递,但这种增强的潜在机制以及吞噬体中MHC-II-肽复合物向细胞表面的递送尚不清楚。我们发现,在DCs中,吞噬体在吞噬数小时后会延伸出许多长管状结构。管状结构的形成需要完整的微管和肌动蛋白细胞骨架以及MyD88依赖性的吞噬体TLR信号传导,但不需要吞噬溶酶体的形成或广泛的蛋白水解。与摄取可溶性配体和TLR刺激后从内溶酶体中出现的管状结构不同,晚期出现的吞噬体管状结构对于将吞噬体衍生的MHC-II-肽复合物递送至质膜并非必不可少。相反,管状化通过使带有TLR信号的吞噬体之间实现最大程度的货物转移来促进MHC-II的呈递。我们的数据表明,DCs中的吞噬体管状结构在功能上与溶酶体中出现的管状结构不同,是吞噬机制的独特适应性变化,有助于TLR信号传导吞噬体之间的货物交换和抗原呈递。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索